- Reaction pathways at the initial steps of trioxane polymerisation
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Cleavage and (re)formation of oxymethylene moieties are essential steps during the build-up of polyoxymethylene (POM), a technically relevant high-performance polymer. To reveal how the catalyst accomplishes the cleavage of oxymethylene moieties, the kinetics of the ring-opening of trioxane was studied. Thereby insights into the initial phase of the growth of oxymethylene chains were obtained. The chain length of short oligomers was controlled with acetic anhydride as transfer agent. With a high ratio of acetic anhydride to trioxane, the first homologues of the series, trioxymethylene diacetate, dioxymethylene diacetate and monooxymethylene diacetate were obtained in excellent yield. The homologues show distinct features in the NMR and IR spectra that were related to their reactivity during chain propagation. Formation of intermediate hemi-acetal oxonium moieties is suggested to be a key step in the reaction pathway. Such molecular level insight may be a crucial factor for further tailoring production and properties of polyoxymethylene as well as introducing oligomeric oxymethylene diacetates to new application fields.
- Hoffmann, Matthias,Bizzarri, Claudia,Leitner, Walter,Müller, Thomas E.
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p. 5594 - 5603
(2018/11/20)
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- Process for preparing 1,1-disubstituted ethylenic monomers
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The present invention relates to a process for preparing 1,1-disubstituted ethylene monomers having general formula (I) from a compound of general formula (II) and an active methylene compound of general formula (III) using a catalytic amount of an ammonium or iminium salt in homogeneous phase or supported on a solid substrate. Said process allows the direct synthesis of the monomers and finds application in the preparation of a wide variety of monomers. The products obtained are reactive monomers of high purity which find application in the field of fast curing adhesives.
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Paragraph 0079
(2015/11/16)
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- PROCESS FOR PREPARING V- TI-P CATALYSTS FOR SYNTHESIS OF 2,3-UNSATURATED CARBOXYLIC ACIDS
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The invention relates to a catalyst composition comprising a mixed oxide of vanadium, titanium, and phosphorus. The titanium component is derived from a water-soluble, redox-active organo-titanium compound. The catalyst composition is highly effective at facilitating the vapor-phase condensation of formaldehyde with acetic acid to generate acrylic acid, particularly using an industrially relevant aqueous liquid feed. Additionally, the catalyst composition is catalytically active towards the formation of acrylic acid from methylene diacetate and methacrylic acid from methylene dipropionate; both reactions are carried out with high space time yields.
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Paragraph 000245
(2014/10/15)
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- HYDROCARBOXYLATION OF METHYLENE DIPROPIONATE IN THE PRESENCE OF PROPIONIC ACID AND A HETEROGENEOUS CATALYST
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Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of methylene dipropionate in the presence of a solid acid catalyst and propionic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the propionic acid stream is readily removed from the glycolic acid and the propionic acid is recycled.
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Paragraph 0122
(2013/10/08)
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- HYDROCARBOXYLATION OF FORMALDEHYDE IN THE PRESENCE OF A HIGHER ORDER CARBOXYLIC ACID AND HETEROGENEOUS CATALYST
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Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a solid acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the glycolic acid stream is readily removed from the carboxylic acid and the carboxylic acid is recycled.
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Paragraph 0128
(2013/10/08)
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- HYDROCARBOXYLATION OF METHYLENE DIPROPIONATE IN THE PRESENCE OF A PROPIONIC ACID AND A HOMOGENEOUS CATALYST
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Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of methylene dipropionate in the presence of a homogeneous acid catalyst and propionic acid. This invention discloses hydrocarboxylations and corresponding homogeneous acid catalyst and glycolic acid separations. The homogeneous acid catalyst is readily separated from the hydrocarboxylation reaction effluent and recycled and the propionic acid is readily removed from the glycolic acid and the propionic acid is recycled
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Paragraph 0142
(2013/10/08)
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- HYDROCARBOXYLATION OF FORMALDEHYDE IN THE PRESENCE OF A HIGHER ORDER CARBOXYLIC ACID AND A HOMOGENEOUS CATALYST
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Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a homogeneous acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding homogeneous acid catalyst and glycolic acid separations. The homogeneous acid catalyst is readily separated from the hydrocarboxylation reaction effluent and recycled and the carboxylic acid is readily removed from the glycolic acid and the carboxylic acid is recycled.
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Paragraph 0133
(2013/10/08)
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- Process for preparing esters and organic halides
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A process for preparing esters and organic halides, which comprises reacting - a salt having a melting point of less than 100°C (at 1 bar) and of the formula ???????? (K+)n X (COO-)n, in which K+ is an organic cation, X (COO-)n is an organic anion having an n-valent organic group X which is substituted by n carboxylate groups COO-, and n is 1, 2 or 3, - with an organic halogen compound (Hal)mY, in which Hal is a halogen atom, Y is an m-valent organic group, and m is 1, 2 or 3, to give an ester and a halide K+ Hal-.
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Page/Page column 5-7
(2013/02/27)
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- Chemoselective protection and deprotection of aldehydes using solid supported reagent (Silica Chloride) under solvent-free conditions
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Silica chloride, a heterogeneous catalyst, has been found to be an efficient catalyst for the protection of aldehydes as acylals under solvent-free conditions, and deprotection of acylals to aldehydes in methanol as a solvent occurred. The reaction takes a shorter time and ensures good to excellent yield of the products.
- Datta, Bandita,Pasha
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experimental part
p. 1160 - 1166
(2011/05/06)
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- SYNTHESIS
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The present invention provides a method of preparing a sulfonyl ether comprising the steps of: v) reacting a sulfonic acid with an anhydride, under continuous vacuum distillation conditions, to form a carboxysulfonate; vi) reacting the carboxysulfonate with an optionally substituted cycloalkane ring containing at least 3 heteroatoms to form a sulfonyl ether pre-mix comprising a sulfonyl ether and at least two additional reaction products each containing at least one ether linkage; vii) subjecting the pre-mix to continuous vacuum distillation conditions to remove at least some of the additional reaction products from the sulfonyl ether pre-mix to provide a crude sulfonyl ether product; and viii) purifying the crude sulfonyl ether product.
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Page/Page column 8-9
(2008/12/07)
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- METHOD OF OBTAINING POLYOXYGENATED ORGANIC COMPOUNDS
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The invention relates to a method of obtaining polyoxygenated organic compounds. The inventive method is characterized in that it comprises the oxidation reaction of a diether, preferably an acetal, with an oxygen source, in the presence of: one or more radical initiating agents, one or more additives that generate a basic reaction medium, and one or more catalysts.
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Page/Page column 8
(2008/06/13)
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- Kinetic resolution of primary alcohols having remote stereogenic centers: lipase mediated kinetic resolution of (±)-3-chloro-3-arylpropanols
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Kinetic resolutions of (±)-3-chloro-3-arylpropanols by lipase mediated acetylation are described for the first time. Acetylation with CCL provided the best enantioselectivity amongst the enzymes used. Enantiomerically enriched products were obtained with up to 78% ee after two successive lipase-catalyzed acetylations. Different substituents on the aromatic ring and bromide, instead of chloride, on the substrates were found to have no drastic influence on the enantioselectivity of the reaction.
- Isleyen, Alper,Tanyeli, Cihangir,Dogan, Oezdemir
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p. 1561 - 1567
(2007/10/03)
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- Boron trifluoride mediated prins reaction of methylene diacetate with styrenes. One-pot synthesis of 3-chloro-3-arylpropanols
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A one-pot procedure was developed for the synthesis of 3-chloro-3- arylpropanols, which are important starting materials for the synthesis of biologically active benzanilide derivatives. Styrenes were reacted with methylene diacetate in the presence of boron trifluoride to give the corresponding 3-chloro-3-arylpropanols in 36-84% yield by the Prins reaction. A strongly electron-donating methoxy substituent at either the ortho or para position of the styrene did not give the expected 3-chloro-3-arylpropanols due to polymerization. Styrene with a strongly electron-withdrawing nitro substituent gave the corresponding 3-chloro-3-arylpropanol in very low yield. Under the same reaction conditions, substituted norbornene gave a tricyclic ether. A very easy procedure for the synthesis of methylene diacetate is also reported. Georg Thieme Verlag Stuttgart.
- Isleyen, Alper,Dogan, Oezdemir
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p. 1427 - 1432
(2007/10/03)
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- Reaction of alkylcarbonyloxymethyl halides with phenols: reevaluating the influence of steric hindrance
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Evidence is presented that contradicts an earlier finding that, in the absence of steric hindrance, the coupling reaction of alkylcarbonyloxymethyl (ACOM) halides with phenols favors acylated product. A one-step synthesis is used to generate sterically unhindered ACOM iodides, which are then reacted with several phenols to give mainly alkylated phenol.
- Thomas, Joshua D.,Sloan, Kenneth B.
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p. 8785 - 8787
(2007/10/03)
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- High molecular weight dibenzoylresorcinol UV absorbers
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Novel dibenzoylresorcinol compositions capable of absorbing ultraviolet light having the formula STR1 where Ar1 and Ar2 are independently substituted or unsubstituted monocyclic or polycyclic aryl groups, R is hydrogen, an aryl group, or a linear or branched alkyl chain having less than about 10 carbons, and Ar3 is an aryl group bearing at least one hydroxyl group. Methods of making the compositions are provided. The novel dibenzoylresorcinol compositions are methylene-bridged dibenzoylresorcinol derivatives having a phenol group on the bridging methylene and are compatible in coating compositions to improve the weatherability of thermoplastic substrates.
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- Ozonolyses of Acetylenes: Trapping of α-Oxo Carbonyl Oxides by Carbonyl Compounds and Stabilization of α-Oxo Ozonides by Derivatizations
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Ozonolyses of 2-butyne (7) or of 3-hexyne (14) in the presence of carbonyl compounds (aldehydes, ketones, acid derivatives) afforded the corresponding mostly labile monocyclic α-oxo ozonides (9, 13a, 16), which could be stabilized and, hence, isolated by subsequent conversion into α-methoximino derivatives. Ozonolyses of 1,4-diacyloxy-substituted (19) and 1-acyloxy-substituted 2-butynes (27) gave bicyclic ozonides (22,31) by intramolecular [3 + 2]-cycloadditions of the corresponding carbonyl oxide intermediates (20, 29). These ozonides could also be stabilized by reactions with O-methylhydroxylamine to give O-methyloximes (23c, 32) or with diazomethane to give epoxy ozonides (25, 34).
- Griesbaum, Karl,Dong, Yuxiang,McCullough, Kevin J.
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p. 6129 - 6136
(2007/10/03)
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- Bis-methylene ether pyridinium compound preparation
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An illustrative embodiment of the invention substitutes solid, non-carcinogenic bis(methanesulfonoxymethyl) ether for bis-chloromethyl ether in a low temperature reaction of about 0°-5° C. for the production of bis-methylene ether pyridinium quaternary compounds. In this way, the production of important nerve agent antidotes (toxogonin, HI-6 and HGG-12) by a method of synthesis using the reactant bis-mesylmethyl ether, is carried out in appreciably greater safety.
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- Ozonolyses of α-Oxo-alkenes: On the Existence of α-Oxo-ozonides
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Ozonolyses of nine acyclic (1a-i) and two cyclic (14, 29) α-oxo-alkenes on polyethylene or in pentane afforded in eight cases (1d-i, 14, 29) isolable α-oxo-ozonides. α-Diozonides (9) are obtained from five of the acyclic α-oxo-alkenes (1a, b, d, g, h).All isolated ozonides are labile; the 2,4-dinitrophenylhydrazones of the α-oxo-ozonides, however, are very stable.Decomposition of the α-oxo-ozonides affords not only the hitherto known fragments, but non-peroxidic isomers (8) of the ozonides, too.
- Griesbaum, Karl,Greunig, Hans-Joachim,Volpp, Willi,Jung, In-Chan
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p. 947 - 956
(2007/10/02)
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- SYNTHESIS OF SORBIC ALCOHOL (2E,4E-HEXADIEN-1-OL)
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The decomposition of 1-acetoxy-3-acetoxymethoxy-4-hexene by the action of acids leads to a 1:2 mixture of 1-acetoxy-2,4-hexadiene and 1-acetoxy-3,5-hexadiene.The same compounds are formed in a ratio of 1:1 during the pyrolysis of 1,3-diacetoxy-4-hexene.
- Vasil'ev, A. A.,Poddubnaya, S. S.,Cherkaev, G. V.,Cherkaev, V. G.
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p. 1457 - 1460
(2007/10/02)
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- Preparation of isochromane derivatives
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A process for the preparation of an isochromane of the formula STR1 in which R 1 and R 2 are identical or different and denote hydrogen, lower alkyl or lower alkoxy, or together form a cyclopentane or cyclohexane ring which is optionally substituted by lower alkyl andR 3 denotes hydrogen or lower alkyl,comprising reacting an alcohol of the formula STR2 with formaldehyde and a carboxylic acid anhydride of the formula STR3 or with a methylene diester of the formula STR4 in which R 4 represents a lower alkyl radical, in the presence of an acid catalyst. The products are known, having a musk-like odor.
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- Alkane acetates produced by oxidative esterification of olefins over transition metal borates in the presence of acetic acid
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A process for the production of alkane acetates from olefins in the presence of a transition metal borate catalyst, oxygen and acetic acid alone via oxidative esterification is described. The reaction is conducted at a temperature in the range of 120° to 220° C. and a pressure of 1 atmosphere or greater. Alkane diacetates and hydroxy acetates are produced which may be used as precursors to alkylene oxides, alkylene glycols and other useful compounds.
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- ELECTROGENERATED BASES VII. NOVEL SYNTHESES OF ETHYL GLYOXALATE AND DIETHYL KETOMALONATE VIA ELECTROGENERATED SUPEROXIDE
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Using electrogenerated tetraalkylammonium superoxide plus oxygen ethyl cyanoacetate has been converted (a) directly to ethyl glyoxylate and (b) in a "one-pot" two-step synthesis to the oxomalonate.
- Sugawara, M.,Baizer, M. M.
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p. 2223 - 2226
(2007/10/02)
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- Electrogenerated Bases. VI. Reaction of Electrogenerated Superoxide with Some Carbon Acids. II.
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Electrogenerated superoxide and molecular oxygen were allowed to react sequentially with a number of esters, nitriles, N,N-dialkylamides, sulfones, and aliphatic nitro compounds.The α-methyl groups in these compounds bore aliphatic and/or aromatic substituents.When the electron-withdrawing group (EWG) of these carbon acids could be displaced intact (nitile 2, ArSO2 4, nitro) good to excellent yields of the corresponding carbonyl compounds could be obtained.The efficiency of the transformation depended upon the nature of the substituents: α,α-diphenyl (e.g., 2a) > α-methyl-α-phenyl (2b) > α,α-dimethyl.By conducting the electrolysis in the presence of acetic anhydride it was shown that the known conversion of phenylacetonitrile (2d) to benzoic acid did indeed proceed via benzaldehyde.When the EWG itself could be cleaved (esters 1, N,N-dialkyl-amides 3), this methodology produced α-hydroxylated compounds and the products resulting from fragmentation of the EWG and also from its complete displacement.The effects of the α-substituents were similar to those above.
- Sugawara, M.,Baizer, M. M.,Monte, W. T.,Little, R. D.,Hess, U.
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p. 509 - 518
(2007/10/02)
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