Process for the Preparation of Eserethole

摘要

PCT No. PCT/EP93/01353 Sec. 371 Date Dec. 19, 1994 Sec. 102(e) Date Dec. 19, 1994 PCT Filed May 28, 1993 PCT Pub. No. WO93/24455 PCT Pub. Date Dec. 9, 1993.Eserethole of formula <IMAGE> (VII) is prepared from 1,3-dimethyl-5-hydroxy-oxindole compound II which is acylated in the first step to obtain 1,3-dimethyl-5-acyloxyoxindole (III). The product is reacted with chloroacetonitrile to obtain 1,3-dimethyl-3-cyanomethyl-5-acyloxy-oxindole (IV). The 5-acyloxy group is hydrolyzed and the hydroxy group is ethoxylated with ethyl halides or sulfate. Then the product is cyclized by treatment with sodium bis-(methoxy-ethoxy)aluminum hydride, to give O-ethyl-nor-eseroline (VI) and the compound is methylated to give eserethole (VII).