PURPOSE: To readily obtain a compound useful as a synthetic intermediate for diltiazem hydrochloride which is a remedy for angina pectoris and essential hypertension in high purity and yield, by reacting a 4-methoxyphenyl-propionic acid derivative with 2-nitrothiophenol.
CONSTITUTION: A novel threo-2,3-dihydroxy-3-(4-methoxyphenyl)-propionic acid expressed by formula I is reacted with 2-nitrothiophenol expressed by formula II in the presence of a Lewis acid, e.g. boron trifluoride, in a solvent, e.g. methylene chloride, etc., at 0W80°C for 1W120hr to afford the aimed substance expressed by formula III. The reaction is carried out using the compound expressed by formula II in a molar amount of 1W2 times based on the compound expressed by formula I. The novel starting compound expressed by formula I is obtained by reacting readily available trans-4-methoxycinnamic acid expressed by formula IV with an oxidizing agent.
ISHIZUKA YORIYASU
FUTSUKAICHI OSAMU
OHIRA YUTAKA
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