38results about How to "High split yield" patented technology

The invention discloses a preparation method of levo cloperastine fendizoate, which comprises the following steps: carrying out nucleophilic substitution reaction on 4-chlorobenzhydrol and 2-chloroethanol in a benzene organic solvent, so that an intermediate product is obtained; reacting the intermediate product with piperidine, so that racemic cloperastine is obtained; resolving the racemic cloperastine by using a resolving agent in a fatty alcohol solvent, so that levo cloperastine is obtained; and carrying out salt forming reaction on the levo cloperastine and a fendizoic acid, so that levo cloperastine fendizoate is obtained, wherein the resolving agent is an R-substituted dibenzoyl-L-tartaric acid, and R refers to alkyl, alkoxy, -Cl, -F, -Br or -H. In the method provided by the invention, in a fatty alcohol solvent, an R-substituted dibenzoyl-L-tartaric acid is adopted as a resolving agent for carrying out resolving on racemic cloperastine, and the resolving yield is high, so that the obtained levo cloperastine fendizoate has high optical purity, and has a high product yield.

The invention relates to the technical field of medicine preparation, and discloses a preparation method of rotigotine, which uses 5-methoxy-2-tetralone as an initial raw material, reacts with R-α-methylbenzylamine, and undergoes desorption Benzyl reduction, chiral resolution of S-mandelic acid, and then react with propionyl chloride reagent to generate amide compound, then reduce it with sodium borohydride reagent, and finally react with 2-(thiophen-2-yl) 2-nitrobenzenesulfonic acid ethyl Ester reaction to give rotigotine. The preparation process route is that the rotigotine of the present invention has mild preparation conditions, simple operation, high yield of key intermediates, high optical purity, easy industrial scale-up production, and good application prospects.

The invention discloses a synthesis and resolution method of N-[4-(1-aminoethyl)-2,6-difluorophenyl]methanesulfonamide. The synthesis method comprises 3,4,5-trifluorobenzene Ethanone reacts with methanesulfonamide to obtain N-(4-acetyl-2,6-difluorophenyl) methanesulfonamide, and then reacts with hydroxylamine hydrochloride to obtain N-[4-(hydroxylaminoethyl)-2, 6‑difluorophenyl] methanesulfonamide, finally obtained by catalytic hydrogenation. The resolving agent adopted in the resolution method is D-mandelic acid, etc., the solvent used is water, etc., and the resolution temperature is 40-50°C. The synthesis method of the invention has simple operation, low production cost, less environmental pollution, high product purity and high reaction yield, and is suitable for large-scale industrial production. In the resolution method of the present invention, a higher resolution yield and optical purity can be finally obtained by selecting a suitable resolution agent, solvent, resolution temperature, especially the addition method of the resolution agent.

The invention relates to a resolution method of DL-panthenolactone. The resolving agent used in the existing resolution method has low selectivity when resolving DL-panthenolactone, which makes the total utilization rate of DL-panthenolactone low and improves the efficiency of resolving DL-panthenolactone. Cost of production. The resolving agent used in the present invention is an organic base R-NH 2 , where R is C 15 h 15 , comprising the following steps: a) reacting the purified resolving agent with acid, adding water, heating and dissolving, adding dropwise DL-pantothenolactone hydrolyzate, resolving agent: the molar ratio of DL-pantothenolactone=0.5- 0.7:1; b) Suction filter the reaction liquid obtained in a, carry out racemization on the filter cake, recover the resolving agent, add an organic solvent to the filtrate for azeotropic dehydration, distill off the excess organic solvent for crystallization. The present invention obviously improves the selectivity of the resolving agent to D-panthenolactone, improves the total utilization rate of DL-panthenolactone, has high resolution yield, reduces the amount of resolving agent and is easy to recycle repeatedly, reducing Breakdown of the production cost of DL-panthenolactone.

The invention discloses a method for preparing D-serine by kinetic resolution. The method takes DL-serine as raw material and is implemented by esterifying DL-serine with methanol under catalysis of Amberlyst-15 ion exchange resin to obtain DL-serinemethylester, carrying out dynamic kinetic resolution on DL-serinemethylester and resolving agent L-DBTA under action of racemization catalyst to obtain dibasic DL-serinemethylester.L-DBTA, dissociating with hydrochloric acid, and hydrolyzing to obtain D-serine, the target product of the invention. Compared with the prior art, by using the racemization catalyst in the invention, the dynamic continuous conversion of dibasic L-serinemethylester.L-DBTA into dibasic DL-serinemethylester.L-DBTA can be realized with the theoretic conversion rate being approximate to 100%, thus greatly enhancing yield of resolution, reducing operation cost, stabilizing product quality and being suitable for industrialized production.

The invention relates to a method for preparing L-2-aminopropanol by means of splitting DL-2-aminopropanol. The method includes steps of 1), dissolving L-tartaric acid in water to obtain L-tartaric acid aqueous solution; 2), dissolving the DL-2-aminopropanol in alcohol solvents at the room temperature, then stirring the DL-2-aminopropanol and the alcohol solvents under cooling conditions, simultaneously completely dropwise adding the L-tartaric acid aqueous solution into the DL-2-aminopropanol to obtain mixed solution, then cooling the mixed solution until the temperature of the mixed solution reaches 0-5 DEG C, and preserving heat to obtain cooled solution; 3), adding a small quantity of crystal seeds into the cooled solution, allowing the cooled solution to stand still at the temperatures ranging from -15 DEG C to +25 DEG C, crystallizing the cooled solution at the temperatures ranging from -15 DEG C to +25 DEG C for 16-24 hours and separating out L-tartaric acid-L-2-aminopropanol acid salt crystals; 4), dissolving the L-tartaric acid-L-2-aminopropanol acid salt crystals by the aid of alcohol solvents, adding inorganic bases into the L-tartaric acid-L-2-aminopropanol acid salt crystals in batches, stirring the inorganic bases and the L-tartaric acid-L-2-aminopropanol acid salt crystals until amino alcohol is completely free, carrying out suction filtration and carrying out reduced-pressure distillation on filter liquid to obtain the L-2-aminopropanol. The method has the advantages that processes are easy to implement, raw materials are high in utilization rate, and accordingly the method is suitable for large-scale production.

Provided in the present invention is a method for the enzymatic resolution of an isavuconazole intermediate. Enantiomeric impurities in (2R,3S)-isavuconazole intermediate I are hydrolyzed to (2S,3S)-carboxylic acid by-product by nitrilase, and the products are separated and purified to obtain the optically pure (2S,3R)-isavuconazole intermediate I.

This invention provides a optical resolution preparation that substitutes oxygen phosphino-acetic acid, concretely relating to optical resolution preparation of racemoid which consists of [(R)-[(1S)-2-methyl-1-(1-keto-propoxy) propoxy] ( 4-benzene butyl)oxygen phosphino]acetic acid and [(S)-[(1R)-2-methyl-1- (1-keto-propoxy)propoxy](4- benzene butyl)oxygen phosphino]acetic acid. The preparation of this invention uses 10,11-di-H Cinchonidine shown in following formula(1) as resolution agent, compared with present resolution preparation, the yield and optical purity of resolution is obviously raised, it need not recryst many times to depurate, and dosis of resolution agent is reduced.