摘要:
This invention relates to a process for preparing electron deficient olefins, such as 2-cyanoacrylates, using an acid catalyzed two-step process including a transesterification reaction followed by a Knoevenagel condensation reaction.
摘要:
A concise method of producing nylon 11, 12, or 13 precursors from oleic acid or an ester of oleic acid is described. The method involves cross-metathesis reactions as the key C-C bond formation step. Subsequent steps are provided to convert the metathesis product to the corresponding nylon precursors. Also provided are the products of the method.
摘要:
Process for preparing 1,1-disubstituted ethylene monomers 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.
摘要:
Process for the manufacture of an amino ester of formula (I) R 1 -O-C(O)-(CH 2 ) n -NH 2 (I) in which n is an integer from 10 to 15 from an unsaturated ester responding to formula (II) R 1 -O-C(O)-(CH 2 ) m -CH=CH-R 2 (II) in which R 1 is either H or a saturated alkyl group containing from 1 to 5 carbon atoms; R 2 is either H or an alkyl group containing from 1 to 10 carbon atoms, either saturated or containing 1 or 2 unsaturations and bearing optionally a hydroxyl, a carboxylic or an ester group, and m is equal to 7, 8, 9, 10 or 11; said process comprising: submitting the unsaturated ester of formula (II) to a catalytic cross-metathesis reaction with a pentenenitrile chosen among 2-pentenenitrile or 3-pentenenitrile in order to obtain a ester-nitrile responding to formula (III) R 1 -O-C(O)-(CH 2 ) m -CH=CH-(CH 2 ) p -CN (III) in which m is equal to 7, 8, 9, 10 or 11 and p is equal to 0 or 1, and submitting the obtained ester-nitrile of formula (III) to an hydrogenation in order to obtain the amino ester of formula (I).
摘要:
The present invention provides an improved process for the preparation of a compound of formula (I), which comprises the steps of: formula (I), (a) reacting isovaleraldehyde of formula (II) and alkyl cyanoacetate of formula (III) optionally in presence of salts of weak acid and weak base or weak base in a suitable solvent to get 2-cyano-5- methyl-hex-2-enoic acid alkyl ester of formula (IV); (b) reacting 2-cyano-5-methyl-hex-2-enoic acid alkyl ester of formula (IV) with a suitable cyanide source in water or in an organic solvent or mixture thereof to get 2-isobutylsuccinonitrile of formula (V); (c) obtaining optionally 2-isobutylsuccinonitrile of formula (V) by reacting isovaleraldehyde of formula (II) and alkyl cyanoacetate of formula (III) in presence of suitable cyanide source in water or in an organic solvent or mixture thereof in single step; (d) converting 2-isobutylsuccinonitrile of formula (V) to racemic 3-cyano-5-methyl-hexanoic acid or salt thereof of formula (VI) with a genetically modified nitrilase enzyme (Nit 9N_56_2) in water or optionally with an organic co-solvent at appropriate pH and temperature; (e) converting racemic 3-cyano-5-methyl-hexanoic acid or salt thereof of formula (VI) to racemic alkyl 3-cyano-5-methyl-hexanoate of formula (VII) by treatment with alcohol (R3OH) and acidic catalyst or alkyl halide (R3X) in presence of a base in a suitable solvent or a mixture of solvents thereof;.(f) obtaining (S)-alkyl 3 -cyano-5 -methyl -hexanoate of formula (VIII) and (R)-3-cyano-5-methyl- hexanoic acid or salt thereof of formula (X) by enzymatic enantioselective hydrolysis in water or organic solvent or a mixture thereof from racemic alkyl 3-cyano-5-methyl-hexanoate of formula (VII);.(g) obtaining optionally the compound of formula (VII) by racemizing unwanted (R)-3-cyano-5- methyl-hexanoic acid or salt thereof of formula (X) or substantially enriched (R)-3 -cyano-5 - methyl-hexanoic acid salt thereof of formula (X) in presence of a base in organic solvent or a mixture thereof; (h) converting (S)-alkyl 3-cyano-5-methyl-hexanoate of formula (VIII) to pregabalin of formula (I) by hydrolyzing ester group with suitable alkali or alkaline earth metal base followed by hydrogenation optionally in one pot in a solvent selected from water or other organic solvents or a mixture thereof in presence of a suitable hydrogenation catalyst.
摘要:
The invention describes a method for the preparation of substituted 5,6-dihydropyrido[2,3-d]pyrimidin-7(8H)-one compounds of general formula (3) that can be used as selective kinase protein inhibitors, which comprises condensing an a,ß-unsaturated ester of general formula (4) with a propionitrile of general formula (5) in the presence of a specific base and reacting the resulting intermediate with a guanidine compound of general formula (6) or a salt thereof in the presence of another base. The invention also describes novel synthesis intermediates of general formula (1) and of general formula (2).
摘要:
The high temperatures required for cracking the cyanoacrylate oligomers, produced by the Knovenagel condensation of formaldehyde and a cyanoacetate, limit the synthetic diversity and the number of different side chains that can be incorporated into a cyanoacrylate prepared using this method. Accordingly, the diversity of cyanoacrylate monomers prepared industrially is quite limited. Disclosed herein is a method for the preparation of alpha-Cyanoacrylate ester monomers from a variety of phosphonium and ammonium alpha-cyanoacrylate salts. The phosphonium and ammonium alpha-cyanoacrylate salts are of the general formula: (I).
摘要:
L'invention a pour objet un procédé de synthèse d'un α,ω-aminoester (acide) saturé longue chaîne obtenu dans une première étape par réaction de métathèse croisée entre un premier composé acrylique et un second composé mono-insaturé comportant au moins une fonction trivalente, nitrile, acide ou ester, l'un de ces composés comportant une fonction nitrile et l'autre une fonction acide ou ester, en présence d'un catalyseur de métathèse de type carbènes de ruthénium et dans une deuxième étape par l'hydrogénation du nitrile-ester(acide) mono-insaturé obtenu en présence du catalyseur de métathèse de l'étape précédente faisant fonction de catalyseur d'hydrogénation
摘要:
The present invention relates to a process for preparation of teriflunomide via reaction of ethyl 2-cyano-3-hydroxybut-2-enoate with 4-trifluoromethylaniline.