Novel synthesis of furoindole pyridone, pyrazolone and cyanoacethydrazide derivatives from isatin

ABSTRACT

Isatin I reacted with diethyl 2-amino-1-cyanopropen-1,3-dicarboxylate IIa and with 1,1-dicyano-3-carbethoxy-2-aminoprop-1-ene IIb to give the corresponding 3-substituted furoindole derivatives IV. Compound IVa reacted with malononitrile and ethylcyanoacetate to give the 3- substituted-pyridine and pyridone derivatives VI and VIII, respectively. The reaction of isatin with cyanoacethydrazine afforded IX which was cyclised to aminopyrazolone derivative X on boiling its solution in ethanol/triethylamine. Similarly, treatment of istain I with methylpyrazlinone afforded the corresponding derivative XII