Dimethylformamide Dimethyl Acetal (DMFDMA) in Heterocyclic Synthesis: Synthesis of Polysubstituted Pyridines, Pyrimidines, Pyridazine and Their Fused Derivatives

Abstract

Reaction of N,N'-dimethylformamide dimethyl acetal (DMFDMA) with malononitrile dimer 8 (1:1) mole afforded 9 while, this reaction when carried out in (2:1) mole to give amidine 11 which can be used for the preparation of pyrimidine 13, amidine 14 and pyridine 19 when reacted with 4-nitroaniline, 4-methylaniline and alkoxide respectively. Malononitrile dimer reacted with diazonium chloride to give pyridazine 21, which can be reacted with DMFDMA, AcOH/HCl and cyanoacetamide to give pyridazine 22, 23 and pyrido[4,3-c] pyridazine 24 respectively. The latter reacted with DMFDMA to afford tricyclic compound 25.