SOME REACTIONS OF N-(4-ACETYLPHENYL)-2-CYANOACETAMIDE WITH VARIOUS ELECTROPHILIC REAGENTS: SYNTHESIS OF THIAZOLIDINONES, 3,5-DICYANO-6-AMINO-2-OXOPYRIDINE, 2-IMINO-2H-CHROMENE-3-CARBOXAMIDE AND 5-IMINO-3H-CHROMENO[3,4-C]PYRIDINE-1-CARBONITRILE DERIVATIVES

Reactions of N-(4-acetylphenyl)-2-cyanoacetamide (1) with several electrophilic reagents are reported. Thus, N-(4-acetylphenyl)-2-cyano-2-(3-phenylthiazol-2-ylidene)acetamide derivatives 4,5a-c were obtained. 4,6-dimethyl-2-oxo-1-(4-acetylphenyl)-1,2-dihydropyridine-3-carbonitrile (8) and their thiosemicarbazone derivative (9) were synthesized. Treatment of 1 and its thiosemicarbazone derivative 6 with α-cyanocinnamonitrile 10a,b under Michael reaction conditions afforded N-(4-acetylphenyl)-2-cyano-3-(4-methoxyphenyl)acrylamide (12) and 6-amino-4-(4-chlorophenyl)-3,5-dicyano-2-oxo-pyridine derivative 15, respectively. Condensation of 6 with α-halocarbonyl compounds gave 1,3-thiazole derivatives 16a,b & 17a,b which on treatment of 16a, 17a with salicyaldehyde gave 2-iminochromene derivatives 18 and 19, respectively. Treatment of 1 with phenolic aldehydes yielded 2-iminochromenes 21a,b which on treatment with ethanolic HCl gave chromene-2-one derivatives 22a,b, respectively. Treatment of 21a with malononitrile and/or ethyl cyanoacetate gave chromeno[3,4-c]pyridine derivatives 24 & 26. IR, 1HNMR and MS for the new synthesized compounds are cited.