Pyrazolotriazines: a new class of tumour-inhibitory agents

Abstract
A series of pyrazolo-as-triazines have been screened for tumour-inhibitory activity against sarcoma S 180 in mice and a methylcholanthrene-induced tumour in rats. The antitumour activities of ethyl 4-aminopyrazolo[3,2-c]-as-triazine-3-carboxylate (Ig), 6-acetyl- and 6-iodoacetyl-3-methyl-4-methylenepyrazolo[3,2-c]-as-triazine (IIa and IIb respectively) against sarcoma S 180 exceed the inhibitory activity of 6-mercaptopurine against the same tumour.