61results about How to "High enantiomeric purity" patented technology

The present invention relates to a process for the preparation of [S(-)amlodipine-L(+)-hemi taratarte] from RS amlodipine base using L(+) tartaric acid in the presence of dimethyl sulfoxide.

The invention discloses a method for synthesizing a chiraltetrahydro naphthalenederivate through asymmetric hydrogenation on isoquinoline by means of an iridium catalyst. A catalysis system applied in the method is a chiral bi-phosphine complex of metal iridium. The reaction is carried out under the conditions that the temperature is 25-60 DEG C; the volume ratio of tetrahydrofuran to dichloromethane in a solvent, namely a mixed solvent of tetrahydrofuran and dichloromethane is 1:1; the pressure is 13-50 Mpa; the ratio of a substrate to a catalyst is 50:1; the catalyst is a coordination compound of a (1,5-cyclooctadiene) iridium chloridedipolymer and a chiral bi-phosphine ligand. The corresponding chiral 1-position or 3-position substituted tetrahydro naphthalenederivate through hydrogenation on isoquinoline, and the enantiomeric excess of the derivate can reach 96%. The method is simple and practical in operation, raw materials are easy to obtain, the enantioselectivity is high, the yield is high, the reaction has atom economy, and the environment is friendly.

The present invention relates to novel compounds of Formula I and their use in therapeutic treatments. The invention further relates to a novel chiral synthesis of 5,6,7,(8-substituted)-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazines using N-sp3 protective groups. The invention also provides intermediates for use in the synthesis of compounds of Formula I.

The invention discloses a synthetic method of bortezomib, which comprises the following steps of: taking isovaleraldehyde as an initial raw material, taking (R)-methylpropane-2-sulfinamide as a chiral reagent, generating (R,E)-2-methyl-N-(3-methyl butylidene) propane-2-sulfinamide by a condensation and dehydration reaction, then carrying out a nucleophilic addition reaction with pinacol diboron so as to generate (R)-1-N-methylpropane sulfinyl-3-methyl butane-1-pinacol borate ester, afterwards hydrolyzing under an acidic condition so as to obtain pinacol-(R)-1-amino-3-methyl butane-1-borate ester hydrochloride, then reacting with (S)-3-phenyl-2-(pyrazine-2-formamido) propionic acid under the existence of a coupling agent and also hydrolyzing under the action of isobutyl borate so as to generate a final product of the bortezomib. According to the synthetic method of the bortezomib, the (R)-methylpropane-2-sulfinamide which is easy to obtain is used as the chiral induction reagent, so that an obtained intermediate enantiomorph has higher purity, and a bulk drug which is finally obtained has better quality.

The invention provides energy efficient depolymerization of polyesters such as post-consumer polylactic acid. Ultrasonic induced implosions can be used to facilitate the depolymerization. The expanding market of polylactic acid-based plastic products, such as water bottles and packaging materials, has raised concerns of contaminating the recycling stream, which is largely filled with petroleum-based plastics. Thus the development of an energy efficient and economically viable PLA recycling process is urgently needed. Post consumer PLA was exposed to methanol as the suspension media in the presence of organic or ionic salts of alkali metals such a potassium carbonate and sodium hydroxide as depolymerization catalysts to provide high quality lactic acid monomers in high yield.

The present invention relates to a process for the separation of racemic mixtures comprising development of a denser molecular imprint on silica with a desired enantiomer by sol-gel protocol.

The present invention provides for a process for preparing racemic methyl 6,6-dimethyl-3-azabicyclo[3,1,0]hexane-2-carboxylate, its corresponding salt: (2S, 3R, 4S)-methyl 6,6-dimethyl-3-azabicyclo[3,1,0]hexane-2-carboxylate di-p-toluoyl-D-tartaric acid (“D-DTTA”) salt or a (2R, 3S, 4R)-methyl 6,6-dimethyl-3-azabicyclo[3,1,0]hexane-2-carboxylate di-p-toluoyl-L-tartaric acid salt (“L-DTTA”) in a high enantiomeric excess. This invention also provides for a process for preparing a (2S, 3R, 4S)-methyl 6,6-dimethyl-3-azabicyclo[3,1,0]hexane-2-carboxylate dibenzoyl-D-tartaric acid (“D-DBTA”) salt or a (2R, 3S, 4R)-methyl 6,6-dimethyl-3-azabicyclo[3,1,0]hexane-2-carboxylate L-tartaric acid (“L-DBTA”) salt in a high enantiomeric excess. Further, this invention provides a process for preparing intermediates II, IIB, III, IV, IV salt, V, VI, and VII.

A process for the resolution of each of the enantiomers of methyl-α-5-[4,5,6,7-tetrahydro[3,2-c]thienopyridyl]-(2-chlorophenyl)acetate and salts thereof by diastereomeric crystallization comprising the use of a single optically active resolving agent and at least one solvent.

The invention relates to a method for purifying esomeprazole sodium, which comprises the following steps: after dissolving an esomeprazole sodium crude product in 0.5-10 times of an alcohol solvent, adding a poor solvent, filtering to obtain a solid, dissolving the solid in 0.5-10 times of acetone, crystallizing until the system becomes turbid, adding a poor solvent, filtering, and drying to finally obtain the sample. The method can remove abundant residual solvents which can not be easily removed in the prior art to obtain the high-purity low-solvent-residue high-yield product, and is suitable for industrial production.

The invention provides methods and compositions for preparing amphetamine conjugates, such as lisdexamfetamine, homoarginine-D-amphetamine, and salts thereof. In one embodiment, the invention provides methods of preparing an amphetamine conjugate from a chloramphetamine intermediate.

The present invention relates to the improved and efficient process for the synthesis of antiepileptic drug Lacosamide in high enantiopurity (>98% ee) and better yield. More particularly, the present invention relates to improved and efficient, cost effective process for synthesis of desired (R) isomer of Lacosamide starting from commercially available (S)-benzyl glycidyl ether.

Disclosed herein is a cost effective and industrially feasible process for the preparation of (+) Clopidogrel bisulphate. The present invention further discloses a novel method of precipitation of (+) Clopidogrel bisulphate Form I directly from solvent mix of methanol and acetone in presence of sulfuric acid at a temperature of 25-40° C.

The method for synthesizing high-antimer pure pine sawfly sex pheromone (2S, 3S, 7S)-3,7-dimethyl-2- pentadecyl alcohol ester is characterized by that it uses cheap easily-evailable natural (S)-malicacid with high-antimer purity as raw material, and can high-stereoselectively synthesize a series of important intermediate compounds of (S)-1,3- butanediol 4, (2S, 3S-2-methyl-1,3-butanediol 12, (S)-3-methyl-hendecyl alcohol 8 and (2S,3S,7S)-3,7- dimethyl-2-pentadecyl alcohol 15 of the pine sawfly sex pheromone, then makes the (2S,3S,7S)-3,7- dimethyl-2-pentadecyl alcohol 15 undergo the process of acrylation reaction to obtain the pine sawfly sex pheromone (2S,3S,7S)-3,7-dimethyl-2-pentadecyl alcohol carboxylic ester 16 and 17 with high antimer purity.

The invention discloses a sodium alginate chiral cross-linked membrane and applications thereof. The preparation method of the sodium alginate chiral cross-linked membrane comprises the following steps: weighing a certain amount of sodium alginate, dissolving the sodium alginate into a water solution of acetic acid, carrying out a supersonic treatment to remove the aggregated particle molecules, allowing the system to stand still so as to remove the bubbles; pouring the membrane-forming solution on a clean and smooth glass board at a room temperature, scrapping off the membrane from the glass board with a membrane-scrapping knife, drying for 4 days; putting the dry membrane into an acetone cross-linking agent containing glutaraldehyde and hydrochloric acid to carry out cross-linking reactions; and washing the cross-linked membrane with a large amount of acetone and ultrapure water until the membrane turns neutral so as to obtain the needed chiral cross-linked membrane. The cross-linked membrane is loaded into a normal dialysis device, and then separates D,L-p-hydroxyphenylglycine raceme aqueous solution under the driving of concentration difference, and the enantiomer purity of p-hydroxyphenylglycine in the permeate reaches 60% or more. The raw materials of the membrane are cheap, the purity of the obtained mono-enantiomer is high, and the preparation method of the membrane has the advantages of large throughput, environment-friendliness, low cost, and easiness in continuous operation and massive industrial production.

Process for preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline wherein 1-phenyl-1,2,3,4-tetrahydroisoquinoline is reacted with D-(−)-tartaric acid in a solvent system comprising of methanol and water, preferably at 3.3:1 to 1:1 volume ratio, the crystallization mixture is left for crystallization and (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline is released from obtained crystalline diastereoisomeric salt according to standard procedures. (S)-1-Phenyl-1,2,3,4-tetrahydroisoquinoline is the intermediate in enantiomeric synthesis of solifenacin.

A process for synthetically producing (S)-nicotine ([(S)-3-(1-methylpyrrolidin-2-yl) pyridine]) is provided.

The invention discloses a method for synthesizing a high-enantiomer-purity diprionidae pheromone and a stereo isomer, relates to a diprionidae pheromone and provides a novel method for synthesizing an optically-active high-enantiomer-purity diprionidae pheromone and a stereo isomer. The method comprises the following steps of: selectively synthesizing the high-enantiomer-purity diprionidae pheromone, a homologous compound thereof and the stereo isomer by taking malic acid or (3R)-hydroxy ethyl butyrate as a raw material; and synthesizing a series of important intermediate compounds, including(R)-1,3-butanediol 12a, (S)-1,3-butanediol 12b, (R)-3-methyl-1-bromotridecane 20a (S)-3-methyl-1-bromotridecane 20b as well as chiral 3,7-dimethyl-2-pentadecyl alcohol 21-28, chiral 3,7-dimethyl-2-tridecyl alcohol 29-36 and chiral 3,7-dimethyl-2-undecyl alcohol 37-44. The diprionidae pheromone is obtained by acylating chiral alcohol 21-44.

The present invention provides a compounds the formula (IV):

and methods for producing an α-(phenoxy)phenylacetic acid compound of the formula:

wherein R¹ is a member selected from the group consisting of:

each R² is a member independently selected from the group consisting of (C₁-C₄)alkyl, halo, (C₁-C₄)haloalkyl, amino, (C₁-C₄)aminoalkyl, amido, (C₁-C₄)amidoalkyl, (C₁-C₄)sulfonylalkyl, (C₁-C₄)sulfamylalkyl, (C₁-C₄)alkoxy, (C₁-C₄)heteroalkyl, carboxy and nitro; the subscript n is 1 when R¹ has the formula (a) or (b) and 2 when R¹ has the formula (c) or (d); the subscript m is an integer of from 0 to 3; * indicates a carbon which is enriched in one stereoisomeric configuration; and the wavy line indicates the point of attachment of R¹; and compounds

The present invention relates to an efficient and environmentally friendly process for preparing (3RS)-3-[(2SR)-(2-cyclopentyl-2-hydroxy-2-phenylacetyl)oxy]-1,1-dimethylp- yrrolidinium bromide with high yield and purity suitable for industrial scale applications.