Process for the preparation of anti-hypertensive benzopyran

摘要

A process is disclosed for the preparation of (+/-)-6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-(2-oxo-1-pyrrol idino)-2H-1-benzopyran-3-ol of the Formula (VI) <IMAGE> (VI) from 4-cyanophenol of the Formula (I) <IMAGE> (I) which comprises reacting 4-cyanophenol of the Formula (I) with isoprene, followed with bromination and dehydrobromination steps with formation of intermediates to react with 2-pyrrolidone resulting in obtaining the compound of the Formula (VI).