| abstract |
The invention relates to a method for recovering methyl ester from valsartan mother liquor, and belongs to the technical field of chemical synthesis. The method comprises the following steps: firstly, the valsartan mother liquor is subjected to reduced pressure rotary evaporation to obtain a mixture; secondly, the mixture is sent into a reaction kettle to undergo esterification reaction with methanol to generate L-valsartan methyl ester and D-valsartan Methyl ester, crystallizes D-valsartan methyl ester by cooling; the third, the filtrate reacts with the inorganic base containing alkali metal ions to form salt and crystallizes to obtain L-valsartan methyl ester alkali metal salt solid; the fourth, L -L-Valsartan methyl ester is hydrolyzed by alkali metal salt of valsartan methyl ester. The present invention designs and develops a reaction kettle integrating reaction, crystallization and suction filtration, greatly shortens the recovery time of L-valsartan methyl ester, improves efficiency, reduces product loss, and finally obtains L-valsartan methyl ester The ester purity is above 99.53%. |