N-salicylidene derivatives of pirarubicin

The preparation and biological evaluation of N-salicylidene derivatives of pirarubicin are described. Pirarubicin was treated with various kinds of aryl aldehydes. Most of compounds synthesized here were more active than pirarubicin in vitro. Some of them showed significant prolongation of the survival period in experimental mice by oral administration. Interestingly, a derivative containing forphenicine exhibited the broadest dose-response range by intraperitoneal administration.