Synthesis and cytotoxic activity of 4,6-diaminopyrazolo[3,4-d] pyrimidine riboside and its 3-carbamoyl derivative

Abstract

A number of compounds with valuable biological properties have been found among the pyrazolo[3,4-d]pyrimidines and their nucleosides. Thus, experimental antitumor activity and/or antiparasitic properties have been exhibited by nucleosides of 4-aminopyrazolo[3,4-d]. pyrimidine, allopurinol (4-oxypyrazolo[3,4-d]pyrimidine) [6], and 4-methylmercaptopyrazolo' [3,4-d]pyrimidine [3]. Of particular interest are the nucleosides of pyrazolo[3,4-d]pyrimidines which have residues of functional carboxylic acids in position 3 of the hetero ring. As has been illustrated by nucleosides of 4-substituted and certain 4,6-bisubstituted pyrazolo[3,4-d]pyrimidines, the introuction of a nitrile, carbamoyl, thiocarbamoyl and similar groups to position 3 results in greater cytotoxic and antitumor activity [2, 7, i0, ii].