Journal of the Chinese Chemical Society

Synthesis of Some New 6, 8??Disubstituted 7, 8??Dihydropyrimido [2, 3: 4, 3] pyrazolo [1, 5??a] pyrimidines and 6, 7, 8??Trisubstituted Pyrimido [2, 3: 4, 3] Pyrazolo [1, 5??a] …

YW Ho, CT Yao

Index: Ho, Yuh-Wen; Yao, Chia-Tseng Journal of the Chinese Chemical Society, 2003 , vol. 50, # 2 p. 283 - 296

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Citation Number: 25

Abstract

Abstract Cyclization of 5-cyano-1, 6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine 4 with excess of 85% hydrazine hydrate afforded the 3-amino-4-methyl-6-phenylpyrazolo [3, 4-d] pyrimidine 5, which can react with appropriate Mannich base derivatives 13a-c and chalcones 27a, b to yield the corresponding 6, 8-disubstituted 7, 8-dihydropyrimido [2, 3: 4, 3] pyrazolo [1, 5-a] pyrimidines 15a-c and 30a, b, respectively. On the other hand, the 6, 7, ...