Synthesis of pyrazolo [3, 4??d] pyrimidine derivatives using ketene dithioacetals

Y Tominaga, Y Honkawa, M Hara…

Index: Tominaga; Honkawa; Hara; Hosomi Journal of Heterocyclic Chemistry, 1990 , vol. 27, # 3 p. 775 - 783

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Citation Number: 91

Abstract

Abstract The cyclization of 5-amino-3-methylthiopyrazole-4-carbonitriles or 4-carboxamides 3a-j, which were prepared by the reaction of ketene dithioacetals 1a, b [1a: bis ( methylthiomethylenemalononitrile; 1b: bis (methylthio) methylenecyanoacetamide] with hydrazines (hydrazine hydrate, phenylhydrazine, p-chlorophenylhydrazine, p- nitrophenylhydrazine), with formamide or carbon disulfide proceeded to give the ...