The preparation method of rifapentine

Abstract

The invention discloses a preparation method of rifapentine, and the steps are as follows: rifamycin S is used as a starting material for reacting with dihydroxy methyl tert-butyl amine in a first organic solvent to convert into intermediate rifaoxazine; a catalyst and a reductant are added into a second organic solvent for hydrolysis ring opening of the intermediate rifaoxazine; a rifapentine solution is obtained by condensation of a rifaoxazine hydrolysis product and 1-amino-4-cyclopentyl piperazine; and a rifapentine finished product is obtained by filtration, segmented crystallization at multistage crystallization temperature, first separation, washing, second separation, drying, soaking, third separation, drip washing, spin drying, sieving, drying, and powder mixing refining processes of the rifapentine solution. The preparation method adopts the reductant which can play a role in anti oxidation; different crystallization temperature is adopted in the segmented crystallization process; and by combination with the adding of a crystallization solvent, the crystalline polymorph is uniform, the particles are uniform, the stability is good, and the defects of high impurity content and nonuniform particles of rifapentine processes in the prior art can be solved.

Description

technical field [0001] The invention relates to the field of medicines, in particular to a preparation method of rifapentine. Background technique [0002] According to the data and patent documents, at present, in the public drug synthesis database, the process route of rifapentine is as follows: 0.01ml of 3-formyl rifamycin SV is dissolved in tetrahydrofuran, and 0.011mol of rifamycin SV is added at room temperature 1-Amino-4-cyclopentylpiperazine. The reaction was followed by TLC until the starting material spot disappeared. The solvent was evaporated, and the residue was recrystallized from ethyl acetate to obtain rifapentine with a yield of 55% and a melting point of 179-180°C. This method uses tetrahydrofuran as a solvent, because tetrahydrofuran is easy to oxidize, it is easy to oxidize the aldehyde group into a carboxyl group, which increases impurities and reduces the yield. Contents of the invention [0003] The purpose of the present invention is to provide a...

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Problems solved by technology

This method uses tetrahydrofuran as a solvent, because tetrahydrofuran is easy to oxidize, it is easy to oxidize the aldehyde group into a carboxyl group, which increases impurities and reduces the yield.

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