-OXOANILIDE AS BUILDING BLOCKS IN HETEROCYCLIC SYNTHESIS: A NEW SYNTHESIS OF POLYFUNCTIONALLY SUBSTITUTED PYRIDINES, PYRANS AND PYRIMIDINES

β-Oxoanilide 1 reacted with acetyl isothiocyanate and ethoxycarbonyl isothiocyanate to givepyridine derivatives 6a,b and pyrimidinethiol 8 respectively. While with arylidine malononitrile gave the pyran derivative 12. Similarly, treatment of 1 with arylidine cyanoacetamide or arylidine cyanothioacetamide afforded the pyridine derivatives 13a,b, 14a,b respectively. Condensation of 1 with aromatic aldehyde obtained the cyclohexenones 19a-c. The reaction of 1 with a mixture of aromatic aldehyde and urea or thiourea gave the pyrimidine derivatives 23a,b. Treatment of compound 1 with arylidine acetophenone yield the cyclohexene derivatives 26a,b. Reaction of 1 with a mixture of ethyl cyanoacetate and sulfur yield the thiophene derivative 27. Which was reacted with formamide, potassium thiocyanate and hydrazine to afford the thienopyrimidines 28, 29 and the hydrazide derivative 30. respectively.