Pyrimidine nucleoside derivatives having anti-tumor activity, their preparation and use

Abstract

Compounds of formula (I): ##STR1## wherein: R.sup.1, R.sup.2 and R.sup.3 are independently selected from the group consisting of hydrogen atoms, optionally substituted alkanoyl groups and alkenylcarbonyl groups, PROVIDED THAT at least one of R.sup.1, R.sup.2 and R.sup.3 represents an unsubstituted alkanoyl group having from 5 to 24 carbon atoms, said substituted alkanoyl group or said alkenylcarbonyl group; and one of R.sup.4 and R.sup.5 represents a hydrogen atom and the other represents a cyano group; have valuable anti-tumor activity.

Dependencies are inferred from the claim text.