SYNTHESIS OF O-SUBSTITUTED BENZOPHENONES BY GRIGNARD REACTION OF 3-SUBSTITUTED ISOCOUMARINS

Abstract

ABSTRACT A series of o-substituted benzophenones was prepared by efficient method involving the 3-substituted isocoumarins and phenylmagnesium bromide. The reaction was completed in presence of anhydrous ether under dry ice-solvent bath in few hours with modest to good yields.Key words: Isocoumarins, diketones, aryl, phenyl magnesium bromide, ether, dry ice.e-mail: nawaz_f@yahoo.co.in. INTRODUCTION Synthetic and naturally occurring isocoumarins possess important biological properties. They are useful intermediates in the synthesis of a variety of carbocyclic and heterocyclic compounds 1-6 .In continuous of our interest in carbon-carbon bond formation reaction 7-12 ,the present paper presents an efficient method to synthesize o-substituted benzophenones (2) from 3-substitued isocoumarins (1) and phenyl magnesium bromide in presence of anhydrous ether under dry ice-solvent bath. Benzophenone and its derivatives are important intermediates in dyes, pharmaceutical and other chemical industries