SYNTHESIS OF SOME NEW 3-(2-OXO-2H-CHROMEN-3-YL)-5H-[ 1,3] THIAZOLO [3,2-a] ΡYRIMIDINE-5-ONES

Abstract

Condensation of 3-(2-amino-4-thiazolyl)coumarins (I) with a-acetyl-y-butyrolactone in a mixture of polyphosphoric acid and POCI3 affords 6-(2-chloromethyl)-7-methyl-3-(2-oxo-2H-chromen-3-yl)-5H-[l,3]-thiazolo[3,2-a] pyrimidine-5-one (Ila-f), while condensation of I with ß-ketoesters gives 7-methyl-3-(2-oxo-2H-chromen-3-yl)-5H-[l,3]thiazolo [3,2-a]pyrimidine-5-ones (IIIa-g). Reaction between I and diethyl methoxy methylene malonate under solvent free c onditions gives 3 -(2-oxo-2H-chromen-3-yl)-5H-[l,3]thiazolo[3,2-a]pyrimidine-5-one-6-carboxylic acid ethyl ester (IV). The structures of newly synthesized compounds have been established by elemental analysis and spectral data