| 摘要 |
PURPOSE:To obtain the titled compound useful as an intermediate of vasodilator, easily, by converting 2-hydroxy-3(2'-aminophenylthio)-3-phenylpropionic acid to a specific salt, and acylating and cyclizing the product in one or two steps. CONSTITUTION:The objective compound of formula I useful as an intermediate of diltiazem hydrochloride (a vasodilator), in high yield, in a short time under mild condition, by (1) converting the 2-hydroxy-3-(2'-aminophenylthio)-3-phenylpropionic acid of formula II (Ar is phenyl substituted with lower alkoxy) to the salt of pyridines, tertiary amines, alkali metals or alkaline earth metals, and (2) reacting the salt with an acid anhydride thereby carrying out the acylation of the 2-OH group and the cyclization in one step. As an alternative method, the objective compound is obtained by reacting the above salt with an acid anhydride or an acid halide, and cyclizing the resultant compound of formula III (R is lower alkyl) with an acid anhydride.
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