Alkylation: The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.Alkylating Agents: Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.Palladium: A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.Methyl Methanesulfonate: An alkylating agent in cancer therapy that may also act as a mutagen by interfering with and causing damage to DNA.Nitrogen Mustard Compounds: A group of alkylating agents derived from mustard gas, with the sulfur replaced by nitrogen. They were formerly used as toxicants and vesicants, but now function as antineoplastic agents. These compounds are also powerful mutagens, teratogens, immunosuppressants, and carcinogens.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Allyl CompoundsGuanineIodoacetamide: An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.Iodoacetates: Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.Ethylnitrosourea: A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Methylnitronitrosoguanidine: A nitrosoguanidine derivative with potent mutagenic and carcinogenic properties.O(6)-Methylguanine-DNA Methyltransferase: An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Uracil Mustard: Nitrogen mustard derivative of URACIL. It is a alkylating antineoplastic agent that is used in lymphatic malignancies, and causes mainly gastrointestinal and bone marrow damage.Quinacrine Mustard: Nitrogen mustard analog of quinacrine used primarily as a stain in the studies of chromosomes and chromatin. Fluoresces by reaction with nucleic acids in chromosomes.Sulfhydryl Compounds: Compounds containing the -SH radical.Distamycins: Oligopeptide antibiotics from Streptomyces distallicus. Their binding to DNA inhibits synthesis of nucleic acids.Leucomycins: An antibiotic complex produced by Streptomyces kitasatoensis. The complex consists of a mixture of at least eight biologically active components, A1 and A3 to A9. Leucomycins have both antibacterial and antimycoplasmal activities.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Nylons: Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.Mechlorethamine: A biologic alkylating agent that exerts its cytotoxic effects by forming DNA ADDUCTS and DNA interstrand crosslinks, thereby inhibiting rapidly proliferating cells. The hydrochloride is an antineoplastic agent used to treat HODGKIN DISEASE and LYMPHOMA.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Methylnitrosourea: A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.Monomethylhydrazine: Hydrazine substituted by one methyl group.Epoxy Compounds: Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.Cyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)KetonesHydrocarbons, IodinatedAziridines: Saturated azacyclopropane compounds. They include compounds with substitutions on CARBON or NITROGEN atoms.DNA Glycosylases: A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.DNA Adducts: The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.DNA Damage: Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.Acronine: A pyrano-acridone alkaloid found in RUTACEAE plants.Nitrosourea CompoundsIodoacetic Acid: A derivative of ACETIC ACID that contains one IODINE atom attached to its methyl group.Phosphines: Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Kinetics: The rate dynamics in chemical or physical systems.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).N-Glycosyl Hydrolases: A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.Antineoplastic Agents, Alkylating: A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumor efficacy and the presence in their chemical structures of N-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumor cells are not completely understood. (From AMA, Drug Evaluations Annual, 1994, p2026)Mesylates: Organic salts or esters of methanesulfonic acid.Carbonates: Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)Sulfuric Acid Esters: Organic esters of sulfuric acid.Dimethylnitrosamine: A nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties. It causes serious liver damage and is a hepatocarcinogen in rodents.Nitrosamines: A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.Alkenes: Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)Ethyl Methanesulfonate: An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.

Effect of hepatocarcinogens on the binding of glucocorticoid-receptor complex in rat liver nuclei. (1/1546)

The effects of a number of carcinogens and hepatotoxins on the binding kinetics of the interactions of glucocorticoidcytosol receptor complex with nuclear acceptor sites in rat liver were investigated. Both the apparent sites in rat liver were investigated. Both the apparent concentration of nuclear binding sites and the Kd were significantly diminished following treatment of rats with sublethal doses of the carcinogens aflatoxin B1, diethylnitrosamine, dimethylnitrosamine, thioacetamide, 3'-methyl-4-dimethylaminoazobenzene, 4-dimethylaminoazobenzene, and 3-methylcholanthrene. Treatment with actinomycin D resulted in a slight reduction in the apparent concentration of nuclear acceptor sites but had no effect on the nuclear binding Kd. The hepatotoxic but noncarcinogenic analgesic, acetaminophen, as well as the weakly toxic aflatoxin B1 cognate, aflatoxin B2, were without effect on the kinetics or binding capacity of glucocorticoid-nuclear acceptor site interaction. These experiments suggest that chemically induced alteration of functional glucocorticoid binding sites on chromatin may be involved in the biochemical effects produced in liver by carcinogens of several chemical types. This experimental model may provide a useful approach for further elucidation of early events in carcinogenesis.  (+info)

Effect of sex difference on the in vitro and in vivo metabolism of aflatoxin B1 by the rat. (2/1546)

Hepatic microsome-catalyzed metabolism of aflatoxin B1 (AFB1) to aflatoxin M1 and aflatoxin Q1 and the "metabolic activation" of AFB1 to DNA-alylating metabolite(s) were studied in normal male and female Sprague-Dawley rats, in gonadectomized animals, and in castrated males and normal females treated with testosterone. Microsomes from male animals formed 2 to 5 times more aflatoxin M1, aflatoxin Q1, and DNA-alkylating metabolite(s) than those from females. Castration reduced the metabolism of AFB1 by the microsomes from males by about 50%, whereas ovariectomy had no significant effect on AFB1 metabolism by the microsomes from females. Testosterone treatment (4 mg/rat, 3 times/week for about 6 weeks) of castrated immature males and immature females enhanced the metabolism of AFB1 by their microsomes. A sex difference in the metabolism of AFB1 by liver microsomes was also seen in other strains of rats tested: Wistar, Long-Evans, and Fischer. The activity of kidney microsomes for metabolic activation was 1 to 4% that of the liver activity and was generally lower in microsomes from male rats as compared to those from female rats of Sprague-Dawley, Wistar, and Long-Evans strains. The in vitro results obtained with hepatic microsomes correlated well with the in vivo metabolism of AFB1, in that more AFB1 became bound in vivo to hepatic DNA isolated from male rats and from a female rat treated with testosterone than that isolated from control female rats. These data suggest that the differences in hepatic AFB1 metabolism may be the underlying cause of the sex difference in toxicity and carcinogenicity of AFB1 observed in rats.  (+info)

Anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria. (3/1546)

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the delta subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.  (+info)

G protein activation by human dopamine D3 receptors in high-expressing Chinese hamster ovary cells: A guanosine-5'-O-(3-[35S]thio)- triphosphate binding and antibody study. (4/1546)

Despite extensive study, the G protein coupling of dopamine D3 receptors is poorly understood. In this study, we used guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]-GTPgammaS) binding to investigate the activation of G proteins coupled to human (h) D3 receptors stably expressed in Chinese hamster ovary (CHO) cells. Although the receptor expression level was high (15 pmol/mg), dopamine only stimulated G protein activation by 1.6-fold. This was despite the presence of marked receptor reserve for dopamine, as revealed by Furchgott analysis after irreversible hD3 receptor inactivation with the alkylating agent, EEDQ (N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline). Thus, half-maximal stimulation of [35S]-GTPgammaS binding required only 11.8% receptor occupation of hD3 sites. In contrast, although the hD2(short) receptor expression level in another CHO cell line was 11-fold lower, stimulation by dopamine was higher (2.5-fold). G protein activation was increased at hD3 and, less potently, at hD2 receptors by the preferential D3 agonists, PD 128,907 [(+)-(4aR,10bR)-3,4,4a, 10b-tetrahydro-4-propyl-2H,5H- [1]benzopyrano[4,3-b]-1, 4-oxazin-9-ol] and (+)-7-OH-DPAT (7-hydroxy-2-(di-n-propylamino)tetralin). Furthermore, the selective D3 antagonists, S 14297 ((+)-[7-(N, N-dipropylamino)-5,6,7, 8-tetrahydro-naphtho(2,3b)dihydro-2,3-furane]) and GR 218,231 (2(R, S)-(dipropylamino)-6-(4-methoxyphenylsulfonylmethyl)-1,2,3,4- tetrahydronaphtalene), blocked dopamine-stimulated [35S]GTPgammaS binding more potently at hD3 than at hD2 sites. Antibodies against Galphai/alphao reduced dopamine-induced G protein activation at both CHO-hD3 and -hD2 membranes, whereas GalphaS antibodies had no effect at either site. In contrast, incubation with anti-Galphaq/alpha11 antibodies, which did not affect dopamine-induced G protein activation at hD2 receptors, attenuated hD3-induced G protein activation. These data suggest that hD3 receptors may couple to Galphaq/alpha11 and would be consistent with the observation that pertussis toxin pretreatment, which inactivates only Gi/o proteins, only submaximally (80%) blocked dopamine-stimulated [35S]GTPgammaS binding in CHO-hD3 cells. Taken together, the present data indicate that 1) hD3 receptors functionally couple to G protein activation in CHO cells, 2) hD3 receptors activate G proteins less effectively than hD2 receptors, and 3) hD3 receptors may couple to different G protein subtypes than hD2 receptors, including nonpertussis sensitive Gq/11 proteins.  (+info)

In vitro reactions of butadiene monoxide with single- and double-stranded DNA: characterization and quantitation of several purine and pyrimidine adducts. (5/1546)

We have previously shown that butadiene monoxide (BM), the primary metabolite of 1,3-butadiene, reacted with nucleosides to form alkylation products that exhibited different rates of formation and different stabilities under in vitro physiological conditions. In the present study, BM was reacted with single-stranded (ss) and double-stranded (ds) calf thymus DNA and the alkylation products were characterized after enzymatic hydrolysis of the DNA. The primary products were regioisomeric N-7-guanine adducts. N-3-(2-hydroxy-3-buten-1-yl)adenine and N-3-(1-hydroxy-3-buten-2-yl)adenine, which were depurinated from the DNA more rapidly than the N-7-guanine adducts, were also formed. In addition, N6-(2-hydroxy-3-buten-1-yl)deoxyadenosine and N6-(1-hydroxy-3-buten-2-yl)deoxyadenosine were detected and evidence was obtained that these adducts were formed by Dimroth rearrangement of the corresponding N-1-deoxyadenosine adducts, not while in the DNA, but following the release of the N-1-alkylated nucleosides by enzymatic hydrolysis. N-3-(2-hydroxy-3-buten-1-yl)deoxyuridine adducts, which were apparently formed subsequent to deamination reactions of the corresponding deoxycytidine adducts, were also detected and were stable in the DNA. Adduct formation was linearly dependent upon BM concentration (10-1000 mM), with adduct ratios being similar at the various BM concentrations. At a high BM concentration (750 mM), the adducts were formed in a linear fashion for up to 8 h in both ssDNA and dsDNA. However, the rates of formation of the N-3-deoxyuridine and N6-deoxyadenosine adducts increased 10- to 20-fold in ssDNA versus dsDNA, whereas the N-7-guanine adducts increased only slightly, presumably due to differences in hydrogen bonding in ssDNA versus dsDNA. These results may contribute to a better understanding of the molecular mechanisms of mutagenesis and carcinogenesis of both BM and its parent compound, 1,3-butadiene.  (+info)

Monoclonal antibody 3F3 against conformational epitope of Torpedo acetylcholinesterase. (6/1546)

AIM: To study the type of epitope of native Torpedo acetylcholinesterase (AChE) directed by its monoclonal antibody (McAb) 3F3. METHODS: Enzyme-linked immunosorbent assay (ELISA) was used for the assay of the reaction between antigen and antibody. RESULTS: McAb 3F3 immunoreacted well with the native AChE, but not with the reduced- and alkylated-AChE (RA-AChE) at all. Soman did not interfere the binding of 3F3 with AChE molecule. The synthesized 24-peptide containing the active serine residue of the AChE active center did not react with McAb 3F3. CONCLUSION: 3F3 is a monoclonal antibody against the conformational epitope of Torpedo AChE active center, but dose not occupy the active serine residue of the enzyme.  (+info)

Use of methyl iodide for probing the polarity of the immediate environment of --SH groups in thiolenzymes. Reaction of methyl iodide with thiosubtilisin. (7/1546)

A new approach is proposed for probing the polarity of the immediate environment of -SH groups in thiolenzymes, based on the alkylation of the -SH group with methyl iodide, a relatively small and non-polar molecule. Rate and activation parameters (delta H*, delta S*) for the reaction of the enzyme are compared to those of glutathione, a simple -SH compound alkylated in aqueous medium. The enzyme and model compound are also reacted with iodoacetamide, a polar counterpart of the non-polar methyl iodide. The above method was applied to thiolsubtilisin, an artificial thiolenzyme. 1. The ratio of the rates of alkylation of thiolsubtilisin and glutathione is about 20 times as high with methyl iodide as with iodoacetamide. 2. delta H* and delta S* for enzyme alkylation, as compared to those for glutathione, are remarkably lower with methyl iodide whereas they are slightly higher with iodoacetamide. 3. delta H* and delta S* for alkylation of thiolsubtilisin with methyl iodide are similar to those found with glutathione in 40% dioxane/water mixture. 4. The activation enthalpy and entropy values for the reaction of thiolsubtilisin with D-2-bromo-n-valeramide are lower than those for glutathione reaction. Consequently, in this respect, D-2-bromo-n-valeramide is similar to methyl iodide rather than to iodoacetamide. It is concluded that the -SH group of thiolsubtilisin is located in an environment less polar than water. The concentration of methyl iodide in this non-polar layer is higher than in the bulk solution, which results in an enhanced reaction rate.  (+info)

Thermal effects on an enzymatically latent conformation of coagulation factor VIIa. (8/1546)

Activation of the zymogen factor VII yields an enzyme form, factor VIIa, with only modest activity. The thermal effect on this low activity of factor VIIa and its enhancement by the cofactor tissue factor was investigated. Factor VIIa activity measured with a chromogenic peptide substrate is characterized by an unusual temperature dependency which indicates that the activated protease exists in an equilibrium between a latent (enzymatically inactive) and an active conformation. As shown by calorimetry and activity measurements the thermal effects on factor VIIa are fully reversible below the denaturation temperature of 58.1 degrees C. A model for factor VIIa has been proposed [Higashi, S., Nishimura, H., Aita, K. & Iwanaga, S. (1994) J. Biol. Chem. 269, 18891-18898] in which the protease is supposed to exist primarily as a latent enzyme form because of the poor incorporation into the protease structure of the N-terminal Ile153 released by proteolytic cleavage during activation of factor VII. Binding of tissue factor to factor VIIa is assumed to shift the equilibrium towards an active conformation in which the N-terminal Ile153 forms a salt bridge with Asp343. We corroborate the validity of this model by: (a) chemical modification of factor VIIa; this suggests that the thermal effect on the equilibrium between the active and inactive conformation is reflected in the relative accessibility of the active site and the N-terminal Ile153; (b) measurements of factor VIIa binding to tissue factor indicating that complex formation is favoured by stabilization of the active conformation; and (c) activity measurements of a cross-linked factor VIIa-tissue factor complex; this showed that cross-linking stabilized the active conformation of factor VIIa and essentially prevented its thermally-induced transformation into the inactive state.  (+info)

TY - JOUR. T1 - Asymmetric Synthesis of α,β-Dialkyl-α-phenylalanines via Direct Alkylation of a Chiral Alanine Derivative with Racemic α-Alkylbenzyl Bromides. A Case of High Enantiomer Differentiation at Room Temperature. AU - Soloshonok, Vadim A.. AU - Tang, Xuejun. AU - Hruby, Victor J. AU - Van Meervelt, Luc. PY - 2001/2/8. Y1 - 2001/2/8. N2 - (Matrix Presented) This study demonstrates that the direct alkylation of a Ni(ll)-complex of the chiral Schiff base of alanine with (S)-o-[N-(N-benzylprolyl)amino]-benzophenone, with racemic α-alkylbenzyl bromides, is a synthetically feasible and methodologically advantageous approach to the target α,β-dialkylphenylalanines over previously reported methods. For the first time we report and rationalize a case of a high enantiomer differentiation process at room temperature.. AB - (Matrix Presented) This study demonstrates that the direct alkylation of a Ni(ll)-complex of the chiral Schiff base of alanine with ...
Global Ethyl Bromoacetate Sales Market Report 2018 1 Ethyl Bromoacetate Market Overview 1.1 Product Overview and Scope of Ethyl Bromoacetate 1.2 Classification of Ethyl Bromoacetate by Product Category 1.2.1 Global Ethyl Bromoacetate Market Size (Sales) Comparison by Type (2013-2025) 1.2.2 Global Ethyl Bromoacetate Market Size (Sales) Market Share by Type (Product Category) in 2017 1.2.3 Food Grade 1.2.4 Pharmaceutical Grade 1.3 Global Ethyl Bromoacetate Market by Application/End Users 1.3.1 Global Ethyl Bromoacetate Sales (Volume) and Market Share Comparison by Application (2013-2025) 1.3.2 Chemicals 1.3.3 Pharmaceuticals 1.3.4 Food Industry 1.3.5 Other 1.4 Global Ethyl Bromoacetate Market by Region 1.4.1 Global Ethyl Bromoacetate Market Size (Value) Comparison by Region (2013-2025) 1.4.2 United States Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.3 China Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.4 Europe Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.5 Japan Ethyl ...
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene (or their equivalents).[1] An alkyl group is a piece of a molecule with the general formula CnH2n+1, where n is the integer depicting the number of carbons linked together. For example, a methyl group (n = 1, CH3) is a fragment of a methane molecule (CH4). Alkylating agents use selective alkylation by adding the desired aliphatic carbon chain to the previously chosen starting molecule. This is one of many known chemical syntheses. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline.[2]. In medicine, alkylation of DNA is used in ...
Headline: Bitcoin & Blockchain Searches Exceed Trump! Blockchain Stocks Are Next!. Alkylation Catalysts Market analysis is provided for global market including development trends by regions, competitive analysis of the Alkylation Catalysts market. Alkylation Catalysts Industry report focuses on the major drivers and restraints for the key players. Alkylation Catalysts Market research report also provides granular analysis of the sales, market growth market share, segmentation, revenue forecasts and geographic regions of the market. Alkylation is the transfer of an alkyl group from one molecule to another. Alkylation of isobutane with olefins in the petroleum is an important industrial process to improve the octane number. As the most usually liquid acid catalysts, concentrated sulfuric acid (H2SO4) and hydrofluoric acid (HF) have potential environmental problem especially for the HF alkylation process.. Browse Detailed TOC, Tables, Figures, Charts and Companies Mentioned in Alkylation Catalysts ...
Here, we demonstrate that OTUD4 may serve as a master regulator of alkylation damage resistance through stabilization of the human AlkB homologues. A number of distinct lines of evidence support this role for OTUD4. First, OTUD4 interacts specifically with ALKBH2 and ALKBH3 and encodes a K48‐specific DUB (Fig 1). Consistently, ALKBH3 is subjected to K48‐linked ubiquitination and proteasomal degradation (Fig 2A-D). OTUD4 antagonizes ALKBH3 ubiquitination and stabilizes both ALKBH2 and ALKBH3 in vivo (Fig 2E-H). ALKBH3 protein levels do not correlate well with ALKBH3 mRNA levels in various tumor cell lines but do correlate with OTUD4 levels (Supplementary Fig S2). Finally, overexpression of ALKBH3 in PC‐3 cells, which depend primarily on ALKBH3 instead of ALKBH2 for alkylation damage resistance, is sufficient to rescue alkylation damage sensitivity upon loss of OTUD4 (Fig 7G).. What is most striking is that we find OTUD4 catalytic activity to be apparently dispensable for its stabilization ...
DNA repair of alkylation damage is defective in various cancers. This occurs through somatically acquired inactivation of the MGMT gene in various cancer types, including breast cancers. In addition to MGMT, the two E. coli AlkB homologs ALKBH2 and ALKBH3 have also been linked to direct reversal of alkylation damage. However, it is currently unknown whether ALKBH2 or ALKBH3 are found inactivated in cancer. Methylome datasets (GSE52865, GSE20713, GSE69914), available through Omnibus, were used to determine whether ALKBH2 or ALKBH3 are found inactivated by CpG promoter methylation. TCGA dataset enabled us to then assess the impact of CpG promoter methylation on mRNA expression for both ALKBH2 and ALKBH3. DNA methylation analysis for the ALKBH3 promoter region was carried out by pyrosequencing (PyroMark Q24) in 265 primary breast tumours and 30 proximal normal breast tissue samples along with 8 breast-derived cell lines. ALKBH3 mRNA and protein expression were analysed in cell lines using RT-PCR and
Tang, X.; Soloshonok, V.A.; Hruby, V.J., 2001: Asymmetric synthesis of alpha,beta-disubstituted-alpha-amino acids via direct alkylation of chiral amino acid derivatives with racemic sec-alkyl bromides
Chelated enolates are versatile nucleophiles for palladium-catalysed allylic alkylations. Even with complex allylic substrates the reaction proceed without significant isomerisation. This allows the stereoselective introduction of polyhydroxylated allylic sidechains into amino acids and peptides with retention of the olefin geometry ...
The CC-1065 and duocarmycin family of compounds are ultrapotent antitumour antibiotics which demonstrate activity in the picomolar range. These agents exert their biological effect through a sequence selective alkylation at the N3 position of adenine resulting in apoptosis. Despite the potential of this family to exert themselves as successful chemotherapeutic agents, a lack of clinical success has been observed for these compounds. This has been attributed to a lack of selectivity resulting in off-target side effects and toxicity. For this reason, research now focuses on ways in which these alkylating agents could realise their potential using tumour specific, targeted delivery strategies.. Herein, we investigate the use of a duocarmycin SA analogue, functionalised for solid phasesynthesis, in the design of conjugates for targeted delivery to cancerous tissue via the Thomsen-Friedenreich antigen (T-antigen). This antigen is overexpressed in 90% of primary human carcinomas, yet is cryptic in ...
The value derived for Henrys Law constant H relates to the properties of the substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol [EC no. 700-960-7]. Vapour pressure (VP) and water solubility (WS) were obtained from tests with different samples of the substance (see CSR Chapter 1.3). The molecular weight was determined as average molecular weight of the different commercial products of the substance taking into account the percentage of the components in the products and their respective molecular weights. The 90th percentile of these data was taken as characteristic average molecular weight for the substance (average MW 298 g/mol). The constant H for the substance oligomerisation and reaction product … is calculated using the vapour pressure of 0.044 Pa and the water solubility of 4 mg C/L (= 0.0134 mol/m³), both at 21°C (see Chapter 1.3.). Dimension of H is Pa*m³/mol. H = VP / WS x MW = 0.044 Pa / 4 mg/L x 298 g/mol = 3.278 Pa*m³/mol ...
Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) are converted to a high octane gasoline feedstock. Alkylate currently accounts for a key fraction of the total U.S. gasoline pool; in fact, concerns over emissions have led to an interest in increasing the amount of alkylate used in gasoline. However, environmental and safety concerns present a barrier to this increase, as current processes for alkylate production employ hazardous liquid acids. As yet, a practical process based on solid catalysts has not been identified ¿ conventional fixed bed processes have faced rapid catalyst aging and downtime for regeneration. This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. Moreover, the proposed approach offers the potential for higher quality ...
TY - JOUR. T1 - Direct and stereoselective synthesis of β-mannosides by anomeric o-alkylation. AU - Takahashi, Daisuke. PY - 2016. Y1 - 2016. KW - Anomeric O-alkylation. KW - Glycosylation. KW - Stereoselective. KW - β-mannosylation. UR - http://www.scopus.com/inward/record.url?scp=84997542885&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=84997542885&partnerID=8YFLogxK. U2 - 10.4052/tigg.1608.6E. DO - 10.4052/tigg.1608.6E. M3 - Comment/debate. AN - SCOPUS:84997542885. VL - 28. SP - E119-E120. JO - Trends in Glycoscience and Glycotechnology. JF - Trends in Glycoscience and Glycotechnology. SN - 0915-7352. IS - 164. ER - ...
This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions.. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. An OH-Pd hydrogen bond in Pd(0)-π-olefin complexes of hydroxy-containing oxazoline ligands was identified by density functional theory computations and helped to rationalize the contrasting results obtained employing hydroxy- and methoxy-containing ligands in the catalytic reaction. This type of hydrogen bond was further studied in phenanthroline metal complexes. As expected for a hydrogen bond, the strength of the bond was found to increase with increased electron density at the metal and with increased acidity of the hydroxy protons.. The second part deals with the use of hydroxy- and methoxy-containing phosphinooxazoline ligands in the rhodium- and iridium-catalyzed asymmetric hydrosilylation reaction. The ...
Get 24/7 Alkylation Of Alcohols Homework Help Online from experts on Transtutors.com. ✓25% discount ✓100% Cashback* ✓4144+ Alkylation Of Alcohols Experts. Ask Now ! Get 100% error-free solutions at affordable prices
1.1. Organolithium and Grignard reagents as nucleophiles - Metalation of halogenated compounds - Hydrogen/metal exchange - Halogen/metal exchange - General reactivity of electrophiles - Reaction of Organolithium and Grignard reagents - Diastereoselectivity of nucleophilic addition (Felkin-Anh, Cram - Enantioselectivity of organozinc/aldehyde additions 1.2. Reaction with organocopper reagents 1. Dithianes 2. O-Alkylated cyanohydranes 3. Alpha lithiated vinyl ethers 1.4. Homoenolate equivalents 1.5. Olefination of carbonyl compounds 1. Wittig reaction (Unstabilized ylides) 2. Horner-Emmons modification (stabilized ylides) 3. C.W. Still Modification 4. Peterson reaction 5. Methylenation of carbonyl compounds by Tebbe reagent 1. Reaction with saturated aldehydes and ketones 2. Reaction with α, β-unsaturated ketones 1. Preparation of enolates by α-deprotonation 2. Alkylation - Alkylation of enolates derived from 1,3-dicarbonyl compounds - Alkylation at γ position of 1,3-dicarbonyl compounds - ...
1993) have been devel- oped as generic reagents for introducing fluorine-18 into N-isopropyl groups by the reductive alkylation augmentin sf syrup direct alkylation of secondary amines, FAF488 appears to be augmetnin distributed and shows focally reduced intensity.
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
TY - JOUR. T1 - Sulfhydryl Site-Specific Cross-Linking and Labeling of Monoclonal Antibodies by a Fluorescent Equilibrium Transfer Alkylation Cross-Link Reagent. AU - del Rosario, Renato B.. AU - Wahl, Richard L.. AU - Brocchini, Stephen J.. AU - Lawton, Richard G.. AU - Smith, Richard H.. PY - 1990/1/1. Y1 - 1990/1/1. N2 - The site-specific intramolecular cross-linking of sulfhydryls of monoclonal antibodies via a new class of "equilibrium transfer alkylation cross-link (ETAC) reagents" is described. Following complete or partial reduction of interchain disulfides with dithiothreitol (DTT), two murine IgG2a monoclonal antibodies, 225.28S and 5G6.4, were reacted with a,a-bis[(p-tolylsulfonyl)methyl]-m-aminoacetophenone (ETAC 1a) and a fluorescent conjugated derivative, sulforhodamine B m-(α,α-bis(p-tolylsulfonylmethyl) acetyl)anilide derivative (ETAC 1b). Reducing SDS-polyacrylamide gel electrophoresis analysis of the products from lb indicated the formation of S-ETAC-S interchain heavy and ...
D4337 - 89(2017) Standard Test Methods for Analysis of Linear Detergent Alkylates , linear alkylbenzenes, linear detergent alkylates ,,
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
Visible-light-induced photoredox decarbonylative C-C bond formation with aldehydes is described for the first time. Minisci-type alkylation reactions of N-heteroarenes proceed smoothly at ambient temperature with air as the sole oxidant. The present sustainable protocol uses readily available organofluorescein as a
Description: Subject matter wherein the hydrocarbon feed is treated prior to the alkylation reaction, e.g., by separating nonhydrocarbon therefrom, by separating the feed into several different fractions, etc ...
However, the simplest synthetic approach to the N-9 substituted guanine compounds involves the direct alkylation of appropriately substituted 2-aminopurines e.g. guanine derivatives. There are significant drawbacks to this approach as it always results in a mixture of N-9 and N-7 alkylation products. The undesirable N-7 isomers are produced in large amounts, which in turn necessitate tedious and in-efficient methods of separation such as silica gel chromatography in order to obtain the desired N-9 isomer at a favourable degree of purity. Use of halogenated purines can. hardly be selected as methods for industrial production, as their starting materials are expensive and difficult to acquire, and they demand a reaction with ammonia at high temperature and pressure in order to obtain guanine nucleosides, such as acyclovir, ganciclovir etc. Hence, it is highly desirable to develop a regioscpecific process for the manufacture of ganciclovir ...
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice ...
The Ordinary Ethylated Ascorbic Acid 15% Solution 30ml Olağanüstü Kararlı, Doğrudan C Vitamini Formu Cildi aydınlatmaya ve zararlı çevresel faktörlere karşı
S-Adenosyl-L-Methionine (a.k.a., SAM, AdoMet) is a cofactor that is crucial to many biological processes. Specifically, SAM is a cationic sulfur-based alkylatin...
TY - JOUR. T1 - Alkylation of pyridine-3,5-dicarboxamide and pyridine-3,5-dicarbonitriles by radical substitution. AU - Kanomata, Nobuhiro. AU - Nagahara, Hisashi. AU - Tada, Masaru. PY - 1992/10/1. Y1 - 1992/10/1. N2 - Structural modification of NAD(P) model compounds, N,N,N′,N′ tetramethylpyridine-3,5-dicarboxamide (1), pyridine-3,5-dicarbonitrile (2), and 4-methylpyridine-3,5-dicarbonitrile (3), have been explored by the reaction with alkyl radicals such as the 1-adamantyl, tert-butyi, and isopropyl radicals. The alkyl substitutions of compounds 1, 2, and 3 with the 1-adamantyl and the fert-butyl radical gave both 2-mono and 2,6-disubsti-tution products, whereas the reaction of compound 2 with the isopropyl radical gave 2-mono 6c, 2,4-di 7c, 2,6-di 8c, and 2,4,6-trisubstitution 9c products.. AB - Structural modification of NAD(P) model compounds, N,N,N′,N′ tetramethylpyridine-3,5-dicarboxamide (1), pyridine-3,5-dicarbonitrile (2), and 4-methylpyridine-3,5-dicarbonitrile (3), have been ...
see article for more reactions. Abstract. A Cp*Ir complex bearing a functional bipyridonate ligand is a highly effective and versatile catalyst for the α-alkylation of ketones with primary alcohols under environmentally benign and mild conditions. Furthermore, this complex also exhibited a high level of catalytic activity for the α-methylation of ketones with methanol.. ...
Each sealed reaction vial contains either 75 µmol of BF3K reagent with 100 µmol of K2S2O8 or 250 µmol of tert-butyl peracetate. Typically, the reaction is performed with 6200K white LED or blue LED (450 nm). The alkylation production kit contains 2 sets of vials allowing the screening of two different substrates or 1 substrate in two solvents. Sparging reaction solvents with nitrogen or argon while transferring reagents is important to achieve highest conversions of product. See protocol diagram for instructions.. Protocol at 500 µl volume reaction condition. ...
Press release - Market Research Hub - Global Alkylation Catalyst Market Analysis By Application 2025 | Top Key Players Albemarle, BASF, CRI, Sinopec - published on openPR.com
sensitive.. Recommended solvents are DMSO or CHCl3 with or without H2O/TFA (0.1 ml of TFA in 2 ml of water). H2O/TFA can change the regioselectivity and conversion of the reaction.. Prepare a solution of ...
Starting from N-methyl-1-{(3S,4S)-4-[2-(trifluoromethyl)phenoxy]-3,4-dihydro-1H-isochromen-3-yl}methanamine (1) target compound 2 is prepared using a mild, direct alkylation approach with 2-fluoroethyl trifluoromethanesulfonate.
In this video Ill teach you why alpha-hydrogens are so acidic, and how we can use that property to do some cool organic reactions. Ill talk about keto-enol tautomerism, LDA (lithium diisopropyl amine), alpha-halogenation, alkylation, acylation, beta-alkylation, the aldol reaction, the Claisen condensation, the Robinson annulation, decarboxylation, and the malonic ester synthesis. --Dr. Mike Christiansen from Utah State University
Were found to alkylate all oxygens and nitrogens in nucleic acids , whereas a host of more moderately reactive electrophilic agents typically target nitrogens
Literature References: Antitumor antibiotic; alkylates DNA by interstrand crosslinking of the major groove. Isoln from Streptomyces sahachiroi: T. Hata et al., J. Antibiot. 7A, 107 (1954). Purification: H. Kamada et al., ibid. 8A, 187 (1955). Mechanism of action: J. W. Lown, K. C. Majumdar, Can. J. Biochem. 55, 630 (1977); T. Fujiwara, I. Saito, Tetrahedron Lett. 40, 315 (1999). Proposed structure: J. W. Lown, C. C. Hanstock, J. Am. Chem. Soc. 104, 3213 (1982). Identity with azinomycin B: E. J. Moran, R. W. Armstrong, Tetrahedron Lett. 32, 3807 (1991). Purification: K. Nagaoka et al., J. Antibiot. 39, 1527 (1986). Total structure as azinomycin B: K. Yokoi et al., Chem. Pharm. Bull. 34, 4554 (1986). ...
Digitization process: Scanned using an Epson 750 as 1200 ppi, 48-bit, RGB, .tif; service master changed to black and white, levels and contrast adjusted, sharpened and cropped; derivative resampled to 3000 pixels on the long edge, 24-bit .jpg ...
T. Mathew, S. Shylesh, S. N. Reddy, S. C. Peter, S. K. Date, B. S. Rao and S. D. Kulkarni, Redistribution of cations amongst different lattice sites in Cu1-xCoxFe2O4 ferrospinels during alkylation: magnetic study. , Cat. Lett. 93, 155 - 160 (2004 ...
An enantioselective synthesis of allenes through palladium-catalyzed asymmetric allylic alkylation using a chiral diaminophosphine oxide is described. The asymmetric allylic alkylations proceeded in the presence of a catalytic amount of lithium acetate at 4 °C, affording the chiral allenes in excellent yield with up to 99% ee. ...
Involvement of two endonuclease III homologs in the base excision repair pathway for the processing of DNA alkylation damage in Saccharomyces cerevisiae.
Dottavio-Martin, D.; Ravel, J.M., 1978: Radiolabeling of proteins by reductive alkylation with [14C]formaldehyde and sodium cyanoborohydride
Looking for online definition of ethylated in the Medical Dictionary? ethylated explanation free. What is ethylated? Meaning of ethylated medical term. What does ethylated mean?
Summary of Facts and Submissions. I. The appeal is from the decision of the Opposition Division to maintain the European patent 1 138 750 in amended form.. II. In opposition procedure the Opponent raised inter alia objections with regard to sufficiency of disclosure, lack of novelty and lack of inventive step and cited among others documents. D6: US-A-5 648 586. D7: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, C5s Selective Hydrogenation and Etherification. D8: STRATCO, The 1990 Alkylation Seminar: K. Masters, Amylene Alkylation. D9: NPRA Q&A Sessions: C5 alkylation questions (from 1989 to 1993). D17: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, Etherification. D18: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, Upgrading Alkylation Feedstocks by Hydrogenation. D21: WO-A-97/03148. III. In its decision the Opposition Division concluded inter alia that the Opponent was not allowed to start argumentation for the first time from a combination of documents D7,D17 and D18 at a very ...
The feasibility of distilling alkylation product and technical alkyl phenol in a continuous apparatus was established. The conditions for distilling the alkylation product and technical alkyl phenol was determined. In terms of its preliminary performance characteristics (sedimentation and increase in viscosity), additive BFK prepared on the basis of the target alkyl phenol distilled in the continuous apparatus surpasses the additive prepared on the basis of technical alkyl phenol with the periodic apparatus.(*DISTILLATION
TY - GEN. T1 - Modeling of benzene with ethylene alkylation. AU - Khlebnikova, Elena. AU - Dolganova, Irena. AU - Ivashkina, Elena. AU - Koshkin, Stanislav. PY - 2016/4/19. Y1 - 2016/4/19. N2 - The paper considers the benzene alkylation with ethylene model development with the use of zeolite catalyst. A list of reactions occurring in the alkylation reactor was made and the thermodynamic possibility of determination of these reactions by the change of Gibbs energy was defined. The paper presents the hydrocarbons transformation scheme, which includes the grouping of components on the basis of their reactivity and the degrees of compensation values of the corresponding reactions. Drawing on the obtained data the authors developed the kinetic model of the alkylation of benzene with ethylene.. AB - The paper considers the benzene alkylation with ethylene model development with the use of zeolite catalyst. A list of reactions occurring in the alkylation reactor was made and the thermodynamic ...
The first direct intermolecular regiospecific and highly enantioselective a-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd0 complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific a-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 e.r.; e.r.=enantiomeric ratio). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals, 2-alkyl-butane-1,4-diols, and amines. The concise co-catalytic asymmetric total syntheses of biologically active natural products (e.g., Arundic acid) are disclosed.. ...
TY - JOUR. T1 - Enolate and Other Carbon Nucleophile Alkylation Reactions using 1,2-Cyclic Sulfates as Terminal Epoxide Equivalents. AU - Hoye, Thomas R. AU - Crawford, Khushrav B.. PY - 1994/2/1. Y1 - 1994/2/1. N2 - Enolates of esters and amides as well as α-sulfonyl-, α-cyano-, and α-phosphonyl-substituted anions react with cyclic sulfate 1 to give hydroxylated products arising from nucleophilic attack, on this terminal epoxide equivalent, at the primary carbon.. AB - Enolates of esters and amides as well as α-sulfonyl-, α-cyano-, and α-phosphonyl-substituted anions react with cyclic sulfate 1 to give hydroxylated products arising from nucleophilic attack, on this terminal epoxide equivalent, at the primary carbon.. UR - http://www.scopus.com/inward/record.url?scp=0012518614&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0012518614&partnerID=8YFLogxK. U2 - 10.1021/jo00082a005. DO - 10.1021/jo00082a005. M3 - Letter. AN - SCOPUS:0012518614. VL - 59. SP - 520. EP - ...
Alkylation reactions represent an important organic transformation to form C-C bonds. In addition to conventional approaches with alkyl halides or sulfonates as alkylating agents, the use of unactivated olefins for alkylations has become attractive from both cost and sustainability viewpoints. This Review summarizes transition-metal-catalyzed alkylations of various
0019] In other embodiments the adjusting is done by changing a ratio of isoparaffin to olefin in a feed to the alkylation reactor. In general, lowering the molar ratio of isoparaffin to olefin in the feed will produce a higher level of C5+ hydrocarbons in the process unit that boil above 280° F. (137.8 degree Celsius). In one embodiment, the molar ratio of isoparaffin to olefin in the feed while operating the alkylation reactor in the alkylate mode is from 4:1 to 100:1, such as from 4:1 to 50:1, or from 4:1 to 20:1; and the molar ratio of isoparaffin to olefin in the feed while operating the alkylation reactor in the distillate mode is a lower molar ratio from that used during the alkylate mode, from 0.25:1 to 25:1, such as from 0.25:1 to 20:1, or 0.25:1 to 10:1. In a different embodiment the molar ratio of isoparaffin to olefin in the feed is approximately the same while operating in both the alkylate mode and the distillate mode. In one embodiment, the control system connected to the ...
Looking for online definition of alkylate in the Medical Dictionary? alkylate explanation free. What is alkylate? Meaning of alkylate medical term. What does alkylate mean?
Title: Chiral Pyrrolidine-Based Salen Ligands for the Enantioselective Alkylation of Aromatic Aldehydes. VOLUME: 4 ISSUE: 2. Author(s): M. Elisa da Silva Serra, Dina Murtinho, Albertino Goth and A. M. dA. Rocha Gonsalves. Affiliation:Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal.. Keywords:Pyrrolidine, diamine, Salen, diethylzinc, enantioselective, alkylation. Abstract: A new type of Salen ligands derived from (2R, 3R)-N-benzyl-2,3-diaminopyrrolidine and aromatic hydroxyaldehydes was synthesized and tested in the enantioselective alkylation of aromatic aldehydes with diethylzinc, moderate selectivity being observed. This study represents the application of a new type of Zn- Salen ligands and opens the way to exploring these promising new structures in other enantioselective and biological processes. ...
Friedel-Crafts alkylation involves the alkylation of an aromatic ring with an alkyl halide using a strong Lewis acid, such as ... Friedel-Crafts alkylation has been hypothesized to be reversible. In a retro-Friedel-Crafts reaction or Friedel-Crafts ... Reaction conditions are similar to the Friedel-Crafts alkylation. This reaction has several advantages over the alkylation ... In a green chemistry variation aluminium chloride is replaced by graphite in an alkylation of p-xylene with 2-bromobutane. This ...
Alkylation[edit]. The most industrially significant amines are prepared from ammonia by alkylation with alcohols:[5] ... Amine alkylation Amines Degree of substitution increases Schotten-Baumann reaction Amide Reagents: acyl chlorides, acid ... Alkylation, acylation, and sulfonation[edit]. Aside from their basicity, the dominant reactivity of amines is their ... Such reactions, which are most useful for alkyl iodides and bromides, are rarely employed because the degree of alkylation is ...
Silicotungstic acid is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene: C2H4 + CH3CO2H → CH3CO2C ... Alkylation of carboxylate salts[edit]. Although not widely employed for esterifications, salts of carboxylate anions can be ... Another variation is the Fráter-Seebach alkylation. Other reactions[edit]. *Phenyl esters react to hydroxyarylketones in the ...
Alkylation. Major chemical intermediates from the alkylation with ethylene is ethylbenzene, precursor to styrene. Styrene is ... alkylation, 5) hydration, 6) oligomerization, and 7) hydroformylation. In the United States and Europe, approximately 90% of ...
Bipin V. Vora, Joseph A. Kocal, Paul T. Barger, Robert J. Schmidt, James A. Johnson (2003). "Alkylation". Kirk‐Othmer ... Isobutane is the principal feedstock in alkylation units of refineries. Using isobutane, gasoline-grade "blendstocks" are ...
The alkylation of linear alkenes, even 1- alkenes such as 1-dodecene gives several isomers of phenyldodecane.[11] ... Bipin V. Vora, Joseph A. Kocal, Paul T. Barger, Robert J. Schmidt, James A. Johnson (2003). "Alkylation". Kirk‐Othmer ... They were prepared by the Friedel-Crafts alkylation of benzene with 'propylene tetramer' (also called tetrapropylene) followed ...
AlkylationEdit. Alkyl nitriles are sufficiently acidic to form nitrile anions, which alkylate a wide variety of electrophiles.[ ...
C-alkylationEdit. C-alkylation is a process for the formation of carbon-carbon bonds. For alkylation at carbon, the ... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a ... N-and P-alkylationEdit. N- and P-alkylation are important processes for the formation of carbon-nitrogen and carbon-phosphorus ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ...
N-AlkylationEdit. N-Methylation of aniline with methanol at elevated temperatures over acid catalysts gives N-methylaniline and ... The largest scale industrial reaction of aniline involves its alkylation with formaldehyde. An idealized equation is shown: 2 C ...
S-alkylationEdit. Thiols, or more specific their conjugate bases, are readily alkylated to give thioethers: RSH + R′Br + B → ... Another method entails the alkylation of sodium hydrosulfide. RX + NaSH → RSH + NaX (X = Cl, Br, I). This method is used for ... alkyl halides are converted to thiols via a S-alkylation of thiourea. This multistep, one-pot process proceeds via the ... A related two-step process involves alkylation of thiosulfate to give the thiosulfonate ("Bunte salt"), followed by hydrolysis ...
O-alkylation. Pyridine N-oxides react with alkyl halides to the O-alkylated product Bis-ter-pyridine derivatives adsorbed on ...
The Tsuji-Trost reaction (also called the Trost allylic alkylation or allylic alkylation) is a palladium-catalysed substitution ... Allylic alkylation." J. Am. Chem. Soc. 1973, 95, 292-294. doi:10.1021/ja00782a080. Rios, Itzel Guerrero; Rosas-Hernandez, ... Trost, B. M.; Strege, P. E. "Asymmetric induction in catalytic allylic alkylation." J. Am. Chem. Soc. 1977, 99, 1649-1651. doi: ... The enantioselective version of the Tsuji-Trost reaction is called the Trost asymmetric allylic alkylation (Trost AAA) or ...
... α-alkylation… Mannich... Michael [a]ddition... and α-amination… [reactions] of carbonyl compounds. In the literature, this ...
White, James D.; Sung, Wing Lam (1974). "Alkylation of Hagemann's ester. Preparation of an intermediate for trisporic acid ...
for inducing alkylation reactions. Blass BE (2002): KF/Al2O3 mediated organic synthesis. Tetrahedron, Vol. 58, 9301-9320.. ...
Alkylation with Oxalic Esters. Scope and Mechanism Marina Bährle-Rapp: Springer Lexikon Kosmetik und Körperpflege, S. 130; ISBN ... Dimethyl oxalate is used for alkylation and in the cosmetics industry as a chelating agent. For countries with low oil but ...
It produces random mutations in genetic material by nucleotide substitution; particularly by guanine alkylation. This typically ...
... is a form of alkylation, with a methyl group, rather than a larger carbon chain, replacing a hydrogen atom. These ... The term methylation in organic chemistry refers to the alkylation process used to describe the delivery of a CH3 group. ... Purdie, T.; Irvine, J. C. (1903). "C.?The alkylation of sugars". Journal of the Chemical Society, Transactions. 83: 1021. doi: ... a biophysical method to determine the methylisation state of DNA Alkylation Methoxy Titanium-Zinc Methylenation Petasis reagent ...
γ- Alkylation of allylic alcohols. Generally, the alkylation reaction of organocopper reagents proceed via gamma- alkylation. ... Alkylation of amines using the Gilman reagent Yamamoto and coworkers described an efficient synthetic method for the alkylation ... Amine alkylation reaction The reaction is reported to be favorable in ethereal solvents. This method was proved to be very ... A remarkably enhanced regioselective gamma- attack of allylic halides and direct alkylation of allylic alcohols via RCu.BF3". ...
"A Novel N-Alkylation Reaction". Journal of the American Chemical Society. 75 (3): 744-745. doi:10.1021/ja01099a508. ISSN 0002- ...
The primary difficulty for alkylation reactions employing nitrile anions is over-alkylation. In the alkylation of acetonitrile ... Two exceptions are alkylations with epoxides (the nearby negative charge of the opened epoxide wards off further alkylation) ... Alkylation of a nitrile anion followed by reductive decyanation was employed in the novel synthesis of (2)-9-dotlecen-1-yl ... Simple alkylations take place by SN2 displacement and are subject to the usual stereoelectronic requirements of the process. ...
Amine alkylation represents a common method to get to imine precursors. Amine alkylation by direct SN2 reaction is only ... Alkylation with Allylic and Benzyl Halides". J. Org. Chem. 26 (9): 3576-3577. doi:10.1021/jo01067a645. Baxter, E. W.; Labaree, ... The most useful and standard method of amine alkylation is to have the amine form an amide bond, and subsequently reduce it, ... Amine alkylation (not shown), transforms the molecule to the rearrangement substrate. Significantly, this molecule shows the ...
The Alkylation of Phenol with Alcohols". Journal of the American Chemical Society. 57 (4): 709-711. doi:10.1021/ja01307a034. " ... alkylation, esterification, dehydration, condensation, Mukaiyama aldol addition, and other reactions[citation needed] Other, ...
Lin, S.; Song, C.-X.; Cai, G.-X.; Wang, W.-H.; Shi, Z.-J. (2008). "Intra/Intermolecular Direct Allylic Alkylation via Pd(II)- ... Young, A. J.; White, M. C. (2008). "Catalytic Intermolecular Allylic C-H Alkylation". J. Am. Chem. Soc. 130 (43): 14090-14091. ... In 2008, simultaneous publications described the allylic C-H alkylation of allylarene substrates. These reactions were ...
Catalytic Two-Phase Alkylation of Cyanamide". Synthesis. 1978: 882-883. doi:10.1055/s-1978-24922. Ponsold K, Ihn W (1970). "Die ...
The asymmetric allylic alkylations proceeded in the presence of a catalytic amount of lithium acetate at 4 °C, affording the ... Palladium-Catalyzed Asymmetric Allylic Alkylation of 2,3-Allenyl Acetates Using a Chiral Diaminophosphine Oxide. Authors. *. ... An enantioselective synthesis of allenes through palladium-catalyzed asymmetric allylic alkylation using a chiral ... From carbopalladation/allylic alkylation domino sequence to decarboxylative allenylation, Journal of Organometallic Chemistry, ...
Denaturing PAGE analysis revealed that DNA alkylation activity of polyamide-seco-CBI conjugate 5 was similar to that of ... Comparative analysis of DNA alkylation by conjugates between pyrrole-imidazole hairpin polyamides and chlorambucil or seco-CBI ... We investigated sequence-specific DNA alkylation using conjugates between the N-methylpyrrole (Py)-N-methylimidazole (Im) ...
Alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane ... Alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane ... Alkylation units were installed in petroleum refineries in the 1930s, but the process became especially important during World ... molecules in the gasoline range; alkylation, a process combining an olefin and a paraffin such as isobutane; isomerization, the ...
... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ... In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). ... Methylation is distinct from alkylation in that it is specifically the transfer of one carbon, whereas alkylation can refer to ...
Key to the alkylation of alcohols is the use of catalysts that render the hydroxyl group a good leaving group. The largest ... Amine alkylation (amino-de-halogenation) is a type of organic reaction between an alkyl halide and ammonia or an amine. The ... N-alkylation is a general and useful route to quaternary ammonium salts from tertiary amines, because overalkylation is not ... Examples of N-alkylation with alkyl halides are the syntheses of benzylaniline, 1-benzylindole, and azetidine. Another example ...
C-alkylationEdit. C-alkylation is a process for the formation of carbon-carbon bonds. For alkylation at carbon, the ... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a ... N-and P-alkylationEdit. N- and P-alkylation are important processes for the formation of carbon-nitrogen and carbon-phosphorus ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ...
DuPont is committed to alkylation research and has extensive experience in assisting refiners with alkylation research, design ... STRATCO® alkylation technology is licensed and marketed by DuPont as part of its Clean Technologies portfolio in Overland Park ... DuPont is the world leader in alkylation technology with over 90 units licensed and with more than 800,000 BPSD (31,400 kmta) ... As part of DuPonts commitment to innovation, the alkylation unit at Hengli will utilize the patented XP2 technology in the ...
The output from the first alkylation reaction zone is supplied, at least in part, to a second alkylation zone which is operated ... by the gas phase alkylation of benzene over a molecular sieve aromatic alkylation catalyst followed by liquid phase alkylation ... A feedstock containing benzene and ethylene is supplied to a first alkylation reaction zone containing a molecular sieve ... aromatic alkylation catalyst. The reaction zone is operated at temperature and pressure conditions to cause gas phase ...
A palladium-catalyzed asymmetric allylic alkylation (AAA) is used to set the spiro(pyrrolidine-oxindo... ... A palladium-catalyzed asymmetric allylic alkylation (AAA) is used to set the spiro(pyrrolidine-oxindole) stereogenic center. ...
Browse Sigma-Aldrichs Alkylation Reagents to find products in DMF-Dialkylacetals, Diazoalkales, Esterification Reagents, ... USA Home > Product Directory > Analytical/Chromatography > Analytical Reagents > Derivatization Reagents > Alkylation Reagents ...
... , Top Key Players Albemarle, BASF, CRI, Sinopec - published on ... 1 Alkylation Catalyst Market Overview. 1.1 Product Overview and Scope of Alkylation Catalyst. 1.2 Alkylation Catalyst Segment ... 1.4 Global Alkylation Catalyst Market Size. 1.4.1 Global Alkylation Catalyst Revenue (2014-2025). 1.4.2 Global Alkylation ... 1.3 Global Alkylation Catalyst Market by Region. 1.3.1 Global Alkylation Catalyst Market Size Region. 1.3.2 North America ...
Adaptive Response Sister Chromatid Exchange GM637 Cell Methyl Guanine Alkylation Damage This is a preview of subscription ... Samson L., Schwartz J.L. (1983) The Induction of Resistance to Alkylation Damage in Mammalian Cells. In: Lawrence C.W. (eds) ... Loveless, A: Possible relevance of 0-6 alkylation of deoxyguanosine to the mutagenicity and carcinogenicity of nitrosamines and ...
D8: STRATCO, The 1990 Alkylation Seminar: K. Masters, Amylene Alkylation. D9: NPRA Q&A Sessions: C5 alkylation questions (from ... In addition, under the heading alkylation pretreatment on page 3 of D7, reference is made to hydrotreating alkylation ... Alkylation pretreatment and the further chapter TAME feedstock pretreatment. Alkylation and TAME production are therefore ... T 1245/09 (Gasoline hydroisomerization/alkylation/UOP) of 20.9.2011. European Case Law Identifier:. ECLI:EP:BA:2011: ...
This Review summarizes transition-metal-catalyzed alkylations of various ... the use of unactivated olefins for alkylations has become attractive from both cost and sustainability viewpoints. ... Alkylation reactions represent an important organic transformation to form C-C bonds. In addition to conventional approaches ... According to the mode of activation, the Review is divided into two sections: alkylation via C-H activation and alkylation via ...
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice ...
Short-term toxicity of Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP) to fish was ...
The viscosity range for the substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP) ( ... the viscosity range for the substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP) ( ...
Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol Type:. legal entity composition of the substance ... Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol EC Number:. 700-960-7. Molecular formula:. not ...
In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. It is a major aspect of the ... In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). ... Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl ... Selective alkylation, or adding parts to the chain with the desired functional groups, is used, especially if there is no ...
Microwave assisted N-alkylation of amine functionalized crystal-like mesoporous phenylene-silica.. Lourenço MA1, Siegel R, ... N-alkylation reaction of amine functionalized phenylene moieties in crystal-like mesoporous silica is successfully achieved ...
An easy Pd-mediated oxidation of primary amines to imines followed by aniline addition enables an alkylation of anilines. The ... Well-defined Co(II) complexes stabilized by a PCP ligand catalyze efficient alkylations of aromatic amines by primary alcohols ... The addition of 4 molecular sieves enables an efficient cobalt(II)-catalyzed N-alkylation of both aromatic and aliphatic amines ... A base-catalyzed/promoted transition-metal-free direct alkylation of amines with either aromatic or aliphatic alcohols provides ...
Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) ... This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin ... polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. ...
Regioselective ketone α-alkylation with simple olefins via dual activation Message Subject. (Your Name) has forwarded a page to ...
Reports emphasize developments in process technology for Alkylation for Motor Fuels that have potential implications for the ... Solid catalyst alkylation processes are being researched as a response to the potential ban of HF acid use because of ... Alkylation has become an important refinery process because of increasing demand for high octane and low vapor pressure ... The flexibility of alkylation in producing a high quality gasoline blending component is evaluated for three types of ...
... alkylation repair homolog 5 (E. coli) Biomolecules from leading suppliers on Biocompare. View specifications, prices, citations ...
  • We investigated sequence-specific DNA alkylation using conjugates between the N-methylpyrrole (Py)-N-methylimidazole (Im) polyamide and the DNA alkylating agent, chlorambucil, or 1-(chloromethyl)-5-hydroxy-1, 2-dihydro-3H-benz[e]indole (seco-CBI). (nii.ac.jp)
  • Comparative analysis of DNA alkylation by conjugates between pyrrole-imidazole hairpin polyamides and chlorambucil or seco-CBI. (nii.ac.jp)
  • Denaturing PAGE analysis revealed that DNA alkylation activity of polyamide-seco-CBI conjugate 5 was similar to that of polyamide-chlorambucil conjugates 1 and 2. (nii.ac.jp)
  • Abstract Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) are converted to a high octane gasoline feedstock. (sbir.gov)
  • abstract = "Reductive alkylation of methyl 3, 5-dimethoxybenzoate with the dibromoalkane and the bromochloroalkane derivatives (4a-d) and (4e-g) afforded, after acid hydrolysis, the corresponding methyl 1- (haloalkyl)-3-methoxy-5-oxocyclohex-3-ene-1-carboxylate derivatives (6a-g). (monash.edu)
  • P h − O − + M e 2 − S O 4 ⟶ P h − O − M e + M e − S O 4 − {\displaystyle \mathrm {Ph{-}O^{-}\ +\ Me_{2}{-}SO_{4}\ \longrightarrow \ Ph{-}O{-}Me\ +\ Me{-}SO_{4}^{-}} } (with Na+ as a spectator ion) On the contrary, the alkylation of amines introduces the problem that the alkylation of an amine makes it more nucleophilic. (wikipedia.org)
  • Microwave assisted N-alkylation of amine functionalized crystal-like mesoporous phenylene-silica. (nih.gov)
  • a) O xidation with Jones Reagent (Aldehydes) b) Bayer-Villiger o xidation (Ketones) b) En amine formation 4. (coursehero.com)
  • DuPont Clean Technologies (DuPont) is pleased to announce that Hengli Petrochemical Company (Hengli), based in Dalian, China, has awarded DuPont a contract to supply the alkylation and spent acid regeneration (SAR) technologies for the new, grassroots refinery in the Changxing Island Harbor Industrial Zone. (prweb.com)
  • The grassroots refinery complex, with the addition of STRATCO® alkylation technology, will allow Hengli to produce a high quality alkylate product (used as a blending component in the gasoline pool) from a 100% isobutylene feed stream. (prweb.com)
  • In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). (wikidoc.org)
  • Alkylation has become an important refinery process because of increasing demand for high octane and low vapor pressure gasoline blending components. (ihs.com)
  • An East Coast refinery test was conducted by Aggreko's Process Services (APS) group and the DuPont Clean Technologies division where chiller systems were installed in the reactor feed section of the STRATCO alkylation unit. (hydrocarbonprocessing.com)
  • The case explored in this paper, cleaner production approaches to reduce fluorine use and waste in the alkylation process at a specific UK oil refinery, illustrates the need to broaden the issues and trade-offs considered in assessing processing and waste management options. (thefreedictionary.com)
  • DuPont STRATCO Refinery Solutions, "HF Alkylation Course," (2006). (thefreedictionary.com)
  • However, the conventional enolate alkylation approach remains problematic due to lack of regioselectivity, risk of overalkylation, and the need for strongly basic conditions and expensive alkyl halide reagents. (sciencemag.org)
  • For upgrading of petroleum, alkylation produces synthetic C7-C8[further explanation needed] alkylate, which is a premium blending stock for gasoline. (wikipedia.org)
  • Alkylation , in petroleum refining , chemical process in which light, gaseous hydrocarbons are combined to produce high-octane components of gasoline . (britannica.com)
  • Alkylation units were installed in petroleum refineries in the 1930s, but the process became especially important during World War II , when there was a great demand for aviation gasoline. (britannica.com)
  • For upgrading of petroleum , alkylation produces a premium blending stock for gasoline. (wikipedia.org)
  • The unique feed stream (100-percent isobutylene) available from the Hengli Petrochemical facility marks the beginning of a new era for alkylation in the gasoline market as the butane-to-alkylate movement grows around the world. (prweb.com)
  • Alkylation is used by the petroleum refining industry to produce a low-vapor-pressure, high-octane gasoline blendstock. (doe.gov)
  • Examples of N-alkylation with alkyl halides are the syntheses of benzylaniline, 1-benzylindole, and azetidine. (wikipedia.org)
  • For alkylation at carbon, the electrophilicity of alkyl halides is enhanced by the presence of a Lewis acid such as aluminium trichloride . (wikipedia.org)
  • Secondary alkyl halides can be tricky to prepare in the lab because the intermediates en route to making them tend to rearrange. (acs.org)
  • The same can be said for using secondary alkyl halides as reactants in the Friedel-Crafts alkylation. (acs.org)
  • The conventional a-alkylation of carbonyl compounds is performed by utilizing stoichiometric amounts of metal enolates for addition to alkyl halides. (docme.ru)
  • Alkylation of α-oxygenated aryl ketones with various alkyl halides proved successful with a cinchonidine catalyst, giving products with high yield and enantioselectivity. (byu.edu)
  • The alkylation of phenols is particularly straightforward since it is subject to fewer competing reactions. (wikipedia.org)
  • Alkylation reactions represent an important organic transformation to form C-C bonds. (rti.org)
  • They're not very electrophilic, and because the Friedel-Crafts alkylation involves generating a carbocation intermediate, you get a lot of competing side reactions and rearrangements," she says. (acs.org)
  • In this context, the catalytic direct a-alkylation of nonstabilized aldehydes and ketones is challenging due to competing side reactions, such as aldol condensations, Cannizzaro and Tishchenko reactions, and N- or O-alkylations. (docme.ru)
  • Well-designed, two-component activation systems with Pd that combine metal catalysis and the employment of stoichiometric or catalytic amounts of an organic catalyst have also been successfully employed in allylic alkylation reactions. (docme.ru)
  • Silicotungstic acid is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene: C2H4 + CH3CO2H → CH3CO2C2H5 It has also been commercialized for the oxidation of ethylene to acetic acid: C2H4 + O2 → CH3CO2H Methylation is the most common type of alkylation, being associated with the transfer of a methyl group. (wikipedia.org)
  • Methylation is the most common type of alkylation, being associated with the transfer of a methyl group . (wikidoc.org)
  • This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. (sbir.gov)
  • This results in high levels of catalyst consumption, making solid catalytic alkylation economically and environmentally unacceptable. (doe.gov)
  • Direct Catalytic Intermolecular -Allylic Alkylation of Aldehydes by Combination of Transition-Metal and Organocatalysis. (docme.ru)
  • There are a few methods for the catalytic intermolecular a-alkylation of nonactivated aldehydes and ketones. (docme.ru)
  • For example, Tamaru and co-workers reported that the a-allylic alkylation of aldehydes is possible in the presence of a catalytic amount of palladium and a slight excess of Et3B. (docme.ru)
  • Herein, we report the first direct intermolecular a-alkylation of aldehydes, which involves catalytic enamine intermediates. (docme.ru)
  • The contract includes the license and engineering design packages for the STRATCO® alkylation and MECS® SAR units. (prweb.com)
  • As part of DuPont's commitment to innovation, the alkylation unit at Hengli will utilize the patented XP2 technology in the STRATCO® Contactor™ reactor. (prweb.com)
  • STRATCO® alkylation technology is licensed and marketed by DuPont as part of its Clean Technologies portfolio in Overland Park, Kansas. (prweb.com)
  • The Kumada coupling employs both a nucleophilic alkylation step subsequent to the oxidative addition of the aryl halide (L = Ligand , Ar = Aryl ). (wikipedia.org)
  • Inspired by the work of Trost and Tsuji on allylic alkylations, the use of previously reported two-component catalyst systems with Pd, and our experience from initial experiments, we decided to pursue a different highly challenging strategy for the a-alkylation of aldehydes and cyclic ketones: the one-pot combination of transition-metal and enamine catalysis (Scheme 1). (docme.ru)
  • However the adoption of zeolites on large scale Friedel-Crafts alkylation has been hampered by the high cost of zeolite production from commercial sources. (uwc.ac.za)
  • The main emphasis of this work is to utilize Pd catalyzed allylic alkylation to synthesize new heterocycles including furans, isoxazolines and new cyclopentane amino-acid analogs in an enantioselective manner. (usf.edu)
  • Adverse outcome pathway development from protein alkylation to liver fibrosis. (wikipathways.org)
  • Carbonyl reductase inactivation may contribute to mouse lung tumor promotion by electrophilic metabolites of butylated hydroxytoluene: protein alkylation in vivo and in vitro. (ucdenver.edu)
  • Alkylating agents utilize selective alkylation by adding the desired aliphatic carbon chain to the previously chosen starting molecule. (wikipedia.org)
  • Selective alkylation, or adding parts to the chain with the desired functional groups, is used, especially if there is no commonly available biological precursor. (wikidoc.org)
  • Currently the only proven alternative is sulphuric acid (see Existing Alkylation Process and Waste Management Section) and the trade-offs are such that there is no general preference for one process over the other (Chapin et al. (thefreedictionary.com)
  • Catalyst production is treated as part of the Background because both HF and sulphuric acid are bulk commodities so that any change in use for this alkylation plant would represent no more than a marginal change in demand. (thefreedictionary.com)
  • The origin of the diastereoselective alkylation of enolates of oxazolopiperidones is studied by means of theoretical calculations and experimental assays. (ub.edu)
  • The alkylation of phenol derivatives can be achieved in good yield via Lewis or Brønsted acid. (rsc.org)
  • S-Alkylation of Thioacridone Derivatives Using Solid-Liquid Phase Transfer Catalysis without Solvent. (ad-astra.ro)
  • Significantly less heme alkylation was observed for the clinically utilized artemisinin derivatives compared to the equipotent trioxolanes included in this study. (asm.org)
  • b) 6-Heteroaryl functions [6-(1,2,4-triazol-4-yl) and 6-(imidazol-1-yl)] were introduced into purine derivatives for regioselective N9 alkylation. (byu.edu)
  • According to the mode of activation, the Review is divided into two sections: alkylation via C-H activation and alkylation via olefin activation. (rti.org)
  • Transtutors has a vast panel of experienced chemistry tutors who specialize in alkylation of alcohol and can explain the different concepts to you effectively. (transtutors.com)
  • The N-alkylation of amines constitutes one of the most widely applied transformations in synthetic chemistry, but established methods often utilise non-renewable feedstocks and must be adapted for a post fossil fuel world. (manchester.ac.uk)
  • However, when the angular carbon adopts an S configuration, the preference for the exo alkylation stems from the intermolecular steric hindrance between the enolate and the alkylating reagent. (ub.edu)
  • In parallel experiments, the effects of pretreatment with PB, Aroclor 1254, pregnenolone-16α-carbonitrile, butylated hydroxytoluene, β-naphthoflavone, and ethanol on DMN-induced alkylation of liver DNA were studied at a DMN dose of 5 µg/kg body weight. (aacrjournals.org)
  • We have earlier reported that alkylation of DNA by the chemical carcinogen dimethyl sulphate, which mainly alkylates N-7 of guanine and N-3 of adenine, causes the formation of partially denatured regions in double-stranded DNA (Rizvi RY, Alvi NK & Hadi SM, Biosci. (portlandpress.com)
  • Taken together, this work reveals a novel, noncanonical mechanism by which an OTU family deubiquitinase regulates its substrates, and provides multiple new targets for alkylation chemotherapy sensitization of tumors. (embopress.org)
  • These results establish that N -alkylation of prosthetic heme during attempted metabolism of olefinic bonds is the cause of cytochrome P -450 destruction. (aspetjournals.org)