Derivatives of 2-acylamido-6-purinethiol and/or 2-acylamido-9-alkyl-6-purinethiol were synthesized and the 2-acylamide derivatives were compared with the parent compound as to their antitumor activity and toxicity. The antitumor activity was assayed mostly with NF-sarcoma, which is known to be highly sensitive to this class of nucleic acid base analogs, but also using other types of tumors.
Among the 2-acylamide derivatives, formamide and especially isobutyroylamide derivatives were found to be the most active, but not markedly more active than the parent compound. A slight decrease in the toxicity was noted among the derivatives with high antitumor activity.
