Synthetic studies on some 3-[(5-arylidene-4-oxo-1,3-thiazolidin-2-yliden) amino]-2-phenylquinazolin-4(3H)-ones and their ethoxyphthalimide derivatives

Abstract

A simple method for the synthesis of title compounds is reported, which were isolated from a series of reactions. After a nucleophilic reaction of 2-phenyl-3,1-benzoxazin-4(3H)-one (1) with thiosemicarbazide to furnish quinazolinylthiourea (2), followed by cyclisation with chloroacetic acid, 3-[(4-oxo-1,3-thiazolidin-2-yliden)amino]-2-phenylquinazolin-4(3H)-one (3) was yielded, which was converted to corresponding arylidene derivatives (5a-f) by treatment with various aldehydes (4a-f). Subsequent condensation of (5a-f) with phthalimidoxyethylbromide gave title compounds (7a-f). The structure of isolated compounds has been determined by means of IR, 1H NMR and mass spectroscopy. ©ARKAT.