CONVENIENT SYNTHESIS OF 2-(5-CHLORO-2-HYDROXYPHENYL) -4H-CHROMEN-4-ONE FROM 1-(2-HYDROXY-5-CHLOROPHENYL) ETHENYLDIPHENYLAMINE

Abstract

The methods of synthesis of flavones mostly by cyclization and condensation of o-hydroxy acetophenone, dehydrogenation of flavanones  or using chalcones as starting materials have very limited applicability hence it is need of the time to go for some alternative methods. The present study reports an experiment where a more convenient method is used to synthesize some substituted flavones from the enamines. The  bromo and nitro substituted 2-(5-chloro-2-hydroxyphenyl)-4H-chromen-4-ones were synthesized by the reaction of bromo and nitro substituted 1-(2-hydroxy-5-chlorophenyl)ethenyldiphenylamines with heptanedioylchloride followed by the cyclization of intermediate thus obtained in the suitable solvents.