Cancerostatica. I. synthesis of some pyrazolo[1,5-a]pyrimidine and pyrazolo [3,4-b] pyridine derivatives

In basic medium 2-phenyl-and 2-(pyridyl-4')-derivatives of 3-dimethylaminoacrlein yields with 5-aminopyrazol-3-one the corresponding pyrazolo [1,5-a] pyrimidines. However, in acid medium, 2-phenyl-3-dimethylaminoacrolein cyclised to derivatives of pyrazolo[3,4-b] pyridine. A reaction mechanism is proposed. Some of these compounds showed significant cytostatic activity against transplanted Ehrlich asc. carcinoma and Nemeth-Kellner lymphoma.