RING-CLOSURE OF -[4-(IMIDAZOL-1-YL)PHENYL]-3-PHENYL-2-PROPEN-1-ONE DERIVATIVES TO POTENTIAL BIOLOGICALLY-ACTIVE COMPOUNDS

-[4-(Imidazol-1-yl)phenyl]-3-phenyl-2-propen-1-one 1 reacted with acet one cyanohydrin, ethyl phenylacetate and cyanoacetamide to give the ad ducts 2, 8 and 10 respectively. Action of hydrazine hydrate on both th e gamma-ketonitrile 2 and the corresponding gamma-ketoacid 4 led to py ridazine derivatives 3 and 5. 4,5-Dihydropyridazinone 5 was dehydrogen ated by the action of bromine, in acetic acid to give pyridazinone 6. Cyclization of acid 8 in acetic medium resulted in alpha-pyrone 9. Cya nopentanamide 10 was converted with hydrochloric acid into delta-ketoa cid 13 which led to alpha-pyrone 14 via an intramolecular dehydration. Refluxing 10 in the presence of acetic acid and ammonium acetate gave 3,4-dihydropyridone 11 which was dehydrogenated to produce pyridone 1 2.