209results about How to "High ee %value" patented technology

A chemical-enzyme method of preparing ursodeoxycholic acid is disclosed. The method adopts chenodeoxycholic acid as an initial substrate, and prepares the ursodeoxycholic acid through a chemical process and a bio-enzyme process in order, wherein 7-KLCA reductase is adopted as a biological catalyst. A situation that an oxidant residual in a process of preparing 7-ketolithocholic acid through a chemical manner causes later enzyme inactivation in the prior art does not occur. A product prepared by the method is high in ee value and low in comprehensive cost.

The invention discloses a transaminase mutant and application thereof. An amino acid sequence of the transaminase mutant is an amino acid sequence obtained by mutation of an amino acid sequence shownin SEQ ID NO:1, and mutation at least comprises one of the following mutation site combinations: T7C+S47C, Q78C+A330C, V137C+G313C, A217C+Y252C and L295C+C328C; or the amino acid sequence of the transaminase mutant is an amino acid sequence which has a mutation site in a mutant amino acid sequence and has 80% homology or above with the mutant amino acid sequence. The transaminase mutant realizes change of protein structure and functions, reduces enzyme dose, increased the ee value of the product and reduces after treatment difficulty, so that the transaminase mutant can be suitable for industrial production.

The present invention discloses a preparation method of carbonate with high optical activity, a main catalyst that is used in the method, and a preparation method of the main catalyst. In the method, racemic epoxy alkane and carbon dioxide have catalytic cycloaddition reaction under chiral double-component catalysts to prepare the optically active cyclic carbonate. The main catalyst is the metal complex of double-chiral Schiff base with coordinated four teeth; the auxiliary catalyst is four substituted tribromide or quaternary ammonium salt.

The invention discloses a synthesis method for a chiral intermediate of atorvastatin calcium, and belongs to the technical field of medical intermediate synthesis. The synthesis method is characterized in that according to the process route, not only are dangerous, highly toxic and expensive chemicals such as butyl lithium, editpotassium cyanide and periodic acid in chemical synthesis prevented from being used, but also an ee value of the chiral intermediate is effectively improved due to usage of a mixed chiral catalysts of titanium iso-propylate and S-xenol. According to the synthesis method, the raw materials are low in cost and easy to obtain, the route operation is easy, the repeatability is good, the yield is very high, and the synthesis method is suitable for industrial production.

The invention discloses a synthesis method of enantiomer-enriched indoline-2-formic acid shown in a formula (I). The synthesis method of the enantiomer-enriched indoline-2-formic acid comprises the following steps: by adopting low-cost and available ortho-position halogen substituted benzaldehyde and N-benzoyl substituted glycine as starting materials, carrying out Erlenmeyer-Plochl cyclization, alkaline hydrolysis and asymmetric catalytic hydrogen for constructing a chiral center, and then carrying out acid catalysis, deprotection and cyclization sequentially or cyclization, acid catalysis and deprotection sequentially, so that the enantiomer-enriched indoline-2-formic acid is obtained. The synthesis method of the enantiomer-enriched indoline-2-formic acid has the advantages that raw materials used in the whole process route are low-cost and easily available, harmful substances or multiple danger special processes are not used, reaction conditions are mild, technological operation is simple, production is safe and stable, the product yield is high, the purity is high, less three wastes are produced, and the energy consumption is low, so that the synthesis method of the enantiomer-enriched indoline-2-formic acid is a process route especially applicable to industrial production. The formula (1) is described in the specification.

The invention discloses a preparation method of chiral alpha-amino acid. Initial raw materials comprising aldehyde and N-acryl substituted glycine undergo Erlenmeyer-Plochl cyclization, hydrolysis or alcoholysis, asymmetric catalytic hydrogenation and acid hydrolysis to obtain the chiral alpha-amino acid compound. The method adopting the above synthesis route has the advantages of mild reaction conditions, simple technological operation, safe and stable production, realization of high yield, good chemical purity and good optical purity of the above obtained product, wide application range, and suitableness for industrial production.

The present invention discloses a reversible acetylcholinesterase inhibitor huperzine-A synthesis method, wherein the route is defined in the specification. The method of the present invention has advantages of easily-available raw materials, simple operation, high yield, low cost, high purity of the final product, easy quality control and the like, and is suitable for industrial production.

The invention relates to preparation of chiral alcohol by an enzymic method, belongs to the field of preparation of a medical intermediate by a gene engineering technology, and provides ketoreductaseand application thereof in preparation of (S)-2-chloro-1-(3,4-difluorophenyl) ethanol. Ketoreductase of which the source is different from that of ketoreductase in the prior art is provided. The concentration of a substrate 2-chloro-1-(3,4-difluorophenyl) ethanone which can be converted by the ketoreductase reaches 350 g/L or above, moreover, ee value of a product (S)-2-chloro-1-(3,4- difluorophenyl) ethanol can reach 99% or above, and meanwhile, the conversion rate of the substrate is 99% or above. According to the technical scheme, by the ketoreductase which is from the new source, the problem that the substrate concentration of (S)-2-chloro-1-(3,4-difluorophenyl) ethanol prepared by enzymatic hydrolysis in industrial application is not high is solved, and the conversion rate of the high-concentration (S)-2-chloro-1-(3,4-difluorophenyl) ethanol and the ee value of the product are increased.

The invention discloses a biological preparation method of (S)-1-(2,6-dichloro-3-fluorophenyl)ethanol. The method comprises the following steps: proportionally mixing co-expressed whole cells, 2,6-dichloro-3-fluoroacetophenone, glucose and a buffer solution, reacting at 30-40 DEG C under the pH value of 5-8, and carrying out after-treatment to obtain the target product, wherein the co-expressed whole cells are gene engineering bacteria containing carbonyl reductase and glucose dehydrogenase. Compared with the prior art, the method disclosed by the invention does not need any exogenous coenzyme, and the catalyst can be easily separated from the reaction solution, so that the technique is greatly simplified and the production cost is lowered. The product has higher yield and ee value, and thus, has favorable industrial application value.

The invention relates to a preparing method of a (2R,4R)-4-methylpiperidine-2-ethyl formate compound. The method comprises the following steps of 1, regarding 4-methyl-2-cyanopiperidine as an initialraw material to be subjected to a hydrolysis reaction through hydrochloric acid to obtain 4-methyl-2-piperidinecarboxylicacid hydrochloride; 2, using ethyl alcohol to esterify 4-methyl-2-piperidinecarboxylicacid hydrochloride to obtain 4-methyl-2-ethyl nipecotate hydrochloride; 3, adding a mixed solvent of methyl tertiary butyl ether and ethyl alcohol, reacting the mixed liquid for pulping, filtering to remove cis-form 4-methyl-2-ethyl nipecotate hydrochloride solid, and collecting mother liquor to obtain anti-form 4-methyl-2-ethyl nipecotate hydrochloride; 4, using L-tartaric acid to split anti-form 4-methyl-2-ethyl nipecotate to obtain the target product (2R,4R)-4-methylpiperidine-2-ethyl formate.

The invention provides a synthetic method of L-glufosinate intermediate shown as a formula II and belongs to the technical field of organic synthesis. The synthetic method comprises the step: under aprotective gas atmosphere, reacting a compound in a formula I with diethyl methyl phosphonate in the presence of a catalyst to obtain an intermediate shown as the formula II; the catalyst is MgBr2+PEG-400, LiBr+PEG-400, KCl+PEG-400, MgBr2+TBAB, MgCl2,MgBr2, TMSBr+TBAB, LaCl3+TBAB or CaCl2. The synthetic method provided by the invention has the benefits that as the catalyst is added, the dosage ofthe diethyl methyl phosphonate is reduced, and the process safety and the reaction rate are improved; meanwhile, the problem of reaction racemization can be solved, so that the ee value of a product is improved, the post-processing operation is simplified, and the process cost is reduced, therefore, the industrial application is more easy to perform.

The invention relates to a novel chiral open-chain pyridoxamine catalyst and a synthesis method and application thereof. The structural general formula of the pyridoxamine catalyst is shown in the specification, wherein R1, R2, R3 and R4 are one of hydrogen, C1-24 alkyl, C1-24 alkyl containing substituent groups, substances shown in the specification and halogen, the substituent groups on C1-24 alkyl are a substance shown in the specification or a substance shown in the specification or a substance shown in the specification or O-Rw or S-Rw' or halogen, and Rx, Rx', Ry, Ry', Ry'', Rz, Rz', Rw and Rw' are one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, benzyl, (1-phenyl)ethyl, 1-naphthyl, 2-naphthyl and halogen. Compared with the prior art, the pyridoxamine catalyst can achieve rapid and efficient synthesis of chiral amino acid, the preparation raw materials are easy to obtain, reaction conditions are mild, cost is low, and when the novel chiral open-chain pyridoxamine catalyst is used for a transamination reaction, the conditions are mild, and the reaction is stable.

The invention discloses a new method for using controllable multi-enzyme cascade reaction to synthesize two kinds of optical pure epoxy compounds. The method is characterized in that coexpression carbonyl reductase in escherichia coli and the recombinant bacteria of styrene monooxygenase are used as biocatalysts, alpha, beta-unsaturated ketone compounds are used as substrate, isopropanol is used as a switch for controlling, and chirality pure allylic epoxy ketone/ alcohol is synthesized.

The invention discloses a novel asymmetric catalytic synthesis method of (S)-naproxen. According to the method, racemic 2-halogenated propionate is used as an initial raw material to perform an asymmetric Kumada cross-coupling reaction with 6-methoxyl-naphthyl grignard reagent in the catalysis of bisoxazoline/cobalt to prepare (S)-naproxen ester, and the ee value is increased by using a re-crystallization method, and the (S)-naproxen is prepared by catalytic hydrogenation. The synthetic route is simple and short, is a two-step reaction, the total yield of the whole synergetic route is 43 percent, and the optical purity of the product is more than 99 percent.

The invention discloses a natural product (+)-Strictifolione synthetic method. The method comprises the steps that 3-benzenepropanal and an Evans chiral auxiliary reagent are subjected to an aldol reaction for diisobutyl aluminum hydride reduction and then subjected to an addition reaction with metal indium activated 3-propylene bromine to obtain a compound shown in the formula 5; silyl enol ether reacts with acrolein under the action of titanium tetraisopropoxide and (R)-1,1-binaphthol, then carbonyl is reduced through sodium borohydride, p-toluenesulfonic acidpyridinium salt is used for cyclization, and acidification treatment is carried out after a methylsulfonyl group becomes a leaving group to obtain a compound shown in the formula 11; a Grubbs second-generation catalyst is used for carrying out a metal coupling reaction on the compounds shown in the formulas 5 and 11 to obtain (+)-Strictifolione. According to the bisection synthetic method, the design is simple and reasonable, operation is easy and convenient, the reaction condition is moderate, linear steps are simple, the product yield is high, and the production cost is greatly reduced.

The invention provides an avalcopam intermediate (a compound shown in a formula I). The compound can be used as an avalcopam raw material or intermediate for synthesizing avalcopam. The invention further provides a preparation method of the atavapam intermediate compound shown in the formula I. The target product atavapam intermediate compound shown in the formula I is obtained through three-step reaction, the whole route design is novel, the chiral resolution process adopted in the prior art is avoided, practicability is high, the yield is high, the reaction speed is high, few by-products are generated, and the preparation method is very suitable for industrial application.