47results about How to "High chiral selectivity" patented technology

The invention discloses threonine aldolase, mutants, threonine aldolase and mutant coding genes, recombinant vectors constructed by coding genes, recombinant genetically engineered bacteria obtained by transformation of recombinant vectors, and threonine aldolase and the application of mutants in the preparation of 2- / 3- / 4-position substituted phenylserine derivatives. The present invention uses threonine aldolase and mutants as biocatalysts, 2- / 3- / 4-position substituted benzaldehyde as substrate, pyridoxal 5-phosphate as coenzyme, glycine / glycine ester as Auxiliary substrate, carry out enzyme-catalyzed reaction in appropriate conditions and media, separate and prepare a series of phenylserine derivatives with different substituents, the total yield of this method is in the range of 76-99%, the ee value of the product is greater than 99%, and the de value is greater than 99%. The range is 70‑99%.

The invention discloses a method for preparing a chiral amino acid tetrazole compound. The method is characterized by synthesizing and preparing the chiral amino acid tetrazole compound by taking cyanophenylalanine and sodium azide as raw materials, dimethyl formamide as a solvent and imidazole polymer ferric salt ionic liquid as a catalyst, and specifically comprises the following steps: mixing the cyanophenylalanine, the sodium azide, the imidazole polymer ferric salt ionic liquid and the dimethyl formamide which are in proportional amounts, heating to 110 to 130 DEG C while stirring, reacting for 20 to 30 hours at a constant temperature, cooling to room temperature, filtering and separating an imidazole polymer ferric salt ionic liquid catalyst, regulating pH (Potential of Hydrogen) ofa separating solution to be neutral with hydrochloric acid, adding an ethyl acetate for extracting and separating liquid, taking a supernatant organic phase, rotationally drying an organic solvent after washing, obtaining white solid, and carrying out vacuum drying, thus obtaining the chiral amino acid tetrazole compound.

The invention provides an L-cyclic alkylamino acid synthesis method and a medicinal composition containing L-cyclic alkylamino acid. The synthesis method comprises the following steps: 1, preparing cyclic alkyl ketonic acid or cyclic alkyl ketonate having a structure represented by formula (I) or formula (II); and 2, mixing the cyclic alkyl ketonic acid or cyclic alkyl ketonate with ammonium formate, a leucine dehydrogenase, a formate dehydrogenase and a coenzyme NAD<+>, and carrying out a reduction amination reaction to generate the L-cyclic alkylamino acid, wherein n1 in the formula (I) is not lower than 1, m1 in the formula is not lower than 0, and M1 is H or a univalent cation; n2 in the formula (II) is not lower than 0, m2 in the formula (II) is not lower than 0, and M2 is H or a univalent cation; and the amino acid sequence of the leucine dehydrogenase is represented by SEQ ID No.1. The method utilizes specific leucine dehydrogenase, the formate dehydrogenase and the coenzyme NAD<+> to carry out the reduction amination reaction of the cyclic alkyl ketonic acid or cyclic alkyl ketonate, and has a high raw material conversion rate and a high chiral selectivity.

The invention relates to a preparation method of (S)-2-chloro-1-(6-fluoro-1-chromanone-2-yl)-ethanol and belongs to the technical field of synthesis of drug intermediates. Aiming at solving the existing problems that the chiral purity is low and the separation is difficult, the invention provides the preparation method of the (S)-2-chloro-1-(6-fluoro-1-chromanone-2-yl)-ethanol; the preparation method comprises the following step: carrying out catalytic reduction reaction on a substrate in a mixed solvent of isopropyl alcohol and a non-proton weak-polarity solvent under the catalysis effect oforganic aluminum salt, so as to obtain the product (S)-2-chloro-1-(6-fluoro-1-chromanone-2-yl)-ethanol. According to the preparation method provided by the invention, an isopropyl alcohol and non-proton weak-polarity solvent system is combined and the organic aluminum salt is used for carrying out the catalytic reaction, so that the high chiral selectivity can be realized, and the preparation method has the effects of high chiral purity and high yield.

The present invention relates to a method for preparing Tegoprazan (Tegoprazan) chiral alcohol, in particular to (S)-5,7-difluoro-3,4-dihydro-2 H -Process for the preparation of chromene-4-ol. The method uses 5,7-difluoro-4H-benzopyran-4-one as the starting material, and realizes (S)-5, 7‑difluoro‑3,4‑dihydro‑2 H Preparation of ‑chromene‑4‑ol.

The invention relates to the technical field of pharmaceutical intermediates, in particular to a method for preparing an enone reductase and a buvaracetam intermediate, the preparation method comprising the following steps: under the catalysis of morpholine, valeraldehyde and glyoxylic acid The reaction generates 5-hydroxyl-4-n-propyl-2(5H)-furanone; under the catalysis of sodium borohydride, 5-hydroxyl-4-n-propyl-2(5H)-furanone dehydroxylates to generate 4 ‑n-propyl‑2(5H)‑furanone; in the presence of enone reductase, 4‑n-propyl‑2(5H)‑furanone undergoes a reduction reaction to generate the target product brivaracetam intermediate; the ene The nucleotide sequence of ketoreductase is shown in SEQ ID NO.1, and its amino acid sequence is shown in SEQ ID NO.2. The preparation method of the brivaracetam intermediate of the present invention only needs 3 steps of reaction to prepare the brivaracetam intermediate without additional chemical resolution, the overall process is green and environmentally friendly, the cost is low, and it is easy to implement.

The invention discloses a method for preparing lactam compounds with high chiral purity. The method for preparing the lactam compounds with the high chiral purity includes steps of adding reactive solvents and heavy metal catalysts into a reaction vessel, and stirring the reactive solvents and the heavy metal catalysts for 10-30 minutes; adding reaction raw materials A into the reaction vessel, then adding hydrogen sources into the reaction vessel and carrying out constant-temperature reaction at the temperature ranging from -30 DEG C to 0 DEG C for 20-40 hours; terminating the reaction, filtering reaction products, and rotationally removing organic solvents from the reaction products; adding water and isopropyl acetate into the reaction products and carrying out extraction; carrying out drying, suction filtration and concentration on organic phase to obtain crude products; re-crystallizing the crude products to obtain lactam products B with high chiral purity. The reduction chiral selectivity can be effectively improved without optional added chiral auxiliaries. The method has the advantages of low production cost, convenience in production and operation, safety, atom economy, easiness in industrial production and the like.