42results about How to "Guaranteed optical purity" patented technology

The invention provides a new enantioselective process for the preparation of (S) -pregabalin, or a pharmaceutical acceptable addition acid salt comprising: acid hydrolysis of the dioxolan ring of a chiral compound of general formula (I) to obtain compound of general formula (II); oxidation of compound (II) to obtain a compound of general formula (III) and transforming compound (III) into compound of general formula (IV); subjecting compound (IV) to basic hydrolysis to obtain a compound of general formula (V) which is reduced to obtain enantiomerically pure S-pregabalin. The invention also provides new chiral intermediates involved in the process.

The application provides a compound of formula I and a preparation method thereof. The application also provides the use of the compound of formula I for synthesizing buvaracetam and the synthesis method. The raw materials involved in the method described in this application are easy to obtain and cheap, and can prepare brivaracetam with high optical purity.

Disclosed is a method that is for producing 1-bromo-1-[3,5-bis(trifluoromethyl)phenyl] ethane having high optical purity, and that is a method containing a step for brominating optically active 1-[3,5-bis(trifluoromethyl)phenyl] ethanol using, as a brominating agent, either a) the combination of a phosphorus halide and hydrogen bromide, b) the combination of 1,2-dibromo-1,1,2,2-tetrachloroethane and the organophosphorus compound represented by general formula I, which is P(R1)(R2)(R3) (in the formula: R1, R2 and R3 each independently indicate a C6-10 aryl group, a C6-10 aryloxy group, a C1-10 alkyl group, a C1-10 alkoxyl group, a C3-6 cycloalkyl group, or a C3-6 cycloalkoxyl group), or c) the combination of N-bromosuccinimide and a dialkyl sulphide.

The invention discloses a preparation method of (S)-N-glycidol phthalimide in a structural formula 1. The method comprises the following steps of: I, phthalimide salt of a structural formula 9 and a compound of a structural formula 10 are subjected to heating reflux for reaction in an alcohols solvent to obtain the compound of a structural formula 11; II, the compound of the structural formula 11 obtained form the step I is reacted with the compound of a structural formula 12 in an aprotic solvent under the action of alkaline to obtain a (S)-N-glycidol phthalimide crude product of the structural formula 1; and III, the (S)-N-glycidol phthalimide crude product of the structural formula 1 obtained from the step II is refined by ethanol to obtain the (S)-N-glycidol phthalimide with the optical purity larger than or equal to 99.0%. The preparation method is simple to operate and good in safety, the optical purity of the obtained product is high (larger than or equal to 99.0%), and the preparation method is suitable for industrial production. The invention also discloses a novel synthetic method of Rivaroxaban.

The invention discloses a preparation method of tamsulosin hydrochloride with high optical purity, and belongs to a medicine technology and a chemical field. A recrystallization method is adopted, crude products of (R)-5-(2-(2-(2-ethoxyphenoxy) ethyl amino) propyl)-2-methoxyl phenyl sulfonamide hydrochloride are refined, so that pure products of the (R)-5-(2-(2-(2-ethoxyphenoxy) ethyl amino) propyl)-2-methoxyl group sulfonamide hydrochloride of which the e.e. value is larger than 99.8% is obtained; a crystallizing solvent adopted by the recrystallization method is a mixed solvent consisting of an organic solvent and water, the organic solvent is selected from one of methanol, ethyl alcohol, acetone, acetonitrile and isopropyl alcohol, and the recrystallization temperature is under 15 DEG C. The preparation method disclosed by the invention is simple to operate, short in period, low in cost and good in repeatability, and can solve the inevitable problem of rework for treatment in the industrial production.

The present invention discloses one kind of 3-hydroxy olefine acid derivative in the structure as shown and its preparation process and application. By means of the inherent chirality of the material and the cross-metathesis of olefine, the product of the present invention, 3-hydroxy olefine acid, has high optical purity. The present invention lays foundation for the industrial preparation of 3-hydroxy olefine acid derivative.

The invention relates to a high-activity double-function catalyst as well as a preparation method and application of the high-activity double-function catalyst. The catalyst is a tetradentate schiff base aluminum complex and the molecule contains more than one quaternary ammonium salt or quaternary phosphonium salt radical. Under a low catalyst concentration, the high-activity double-function catalyst still has the higher catalytic activity; reaction conditions are relatively moderate and a process is simple and convenient; the catalytic efficiency is high and the product selectivity is high; any organic solvent does not need to be added; and when chiral epoxyalkane is used as a reactant, the optical purity of a product can be completely kept.

The invention discloses a method for preparing L-theanine by a chemical method. The method comprises the following steps: firstly, reacting ethylamine with acryloyl chloride in the presence of an alkali to obtain N-ethylacrylamide; secondly, perform Michael addition reaction on chiral auxiliary BPB based glycine Schiff base Ni(II) coordination compound and the N-ethylacrylamide in the presence ofthe alkali to obtain theanine Schiff base Ni(II) coordination compound; and finally, performing acid hydrolysis on the theanine Schiff base Ni(II) coordination compound to prepare the L-theanine. Themethod adopts the chiral auxiliary chemical method to prepare the L-theanine, and constructs a complete theanine fragment through the Michael addition reaction so as to prepare the theanine Schiff base Ni(II) coordination compound, wherein the rigid space structure of the coordination compound can maintain the L-configuration of the theanine so as to ensure the optical purity of the L-theanine. The method can reclaim the chiral auxiliary in high yield, and can elute Ni(II) ions through ion exchange for recycling.

The invention discloses a method for preparing D-sulbenicillin sodium. The method includes steps of removing L-amino acid from L-amino acid salt of D-sulfophenylacetic acid in solvents and carrying out salt forming to obtain D-sulfophenylacetic acid salt; carrying out reaction on the D-sulfophenylacetic acid salt and acylating agents to obtain mixed acid anhydride; dissolving 6-APA in organic solvents under the effect of organic alkali; dropwise adding mixed acid anhydride solution into 6-APA solution, and carrying out sufficient reaction and after-treatment to obtain the D-sulbenicillin sodium. The D-sulfophenylacetic acid is an intermediate. The 6-APA is a matrix. The method has the advantages that the D-sulbenicillin sodium is prepared by the aid of novel synthetic routes, conditions are mild, the method includes stable process and is easy to implement, and the problems of instable processes of existing methods or insufficient optical purity of products and the like can be solved bythe aid of the method.