β-Alkoxyvinyl trichloromethyl ketones as N-heterocyclic acylating agent. A new access to 5H-thiazolo[3,2-a]pyrimidin-5-ones

Using trichloromethyl substituent as convenient leaving group for the synthesis of interesting bi-heterocyclic compounds, a series of 6-methyl- and 7-alkyl(aryl)-5H-thiazolo[3,2-a]pyrimidin-5-ones, where alkyl=methyl, n-propyl, isopropyl, isobutyl, n-hexyl, isopentyl and aryl=phenyl, 4-toluyl, 4-chlorophenyl, 4-bromophenyl, 4-methoxyphenyl was obtained from a simple and regiospecific reaction of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones with 2-aminothiazole in good yield (45–89%).