SYNTHESIS OF NOVEL ANGULAR AND LINEAR FUSED [5-6-5] HETEROCYCLES BY THE REACTION OF METHYL CYANO-(3-CYANO-4,5-DIHYDRO-2(3H)-FURANYLIDENE)ACETATE WITH HYDRAZINES AND DIMETHYLFORMAMIDE DIMETHYL ACETAL

摘要

A convenient and efficient method for the synthesis of novel angular and linear fused [5-6-5] three heterocycles is described. Methyl cyano(3-cyano-4,5-dihydro-2(3H)-furanylidene)acetate (1) was reacted with an excess of hydrazine monohydrate to give 3,4'-bipyrazole 5. Compound 5 was condensed with N,N-dimethylformamide dimethyl acetal (DMFDMA) to yield angular dipyrazolopyrimidine 6. On the other hand, pyrazoles 3b-d were obtained by reaction of 1 with hydrazines. Compounds 3b-d were reacted with hydrazine monohydrate, pyrazolopyridines 7a-c were taken. Compounds 7a-c were condensed with DMFDMA to give linear pyrazolotriazolopyridines 8a-c.