Abstract: The invention relates an epoxysuccinamide derivative represented by a formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom, an alkyl or aminoalkyl group, R.sup.2 represents an aminoalkyl group which May be substituted, an aryl group which may be substituted, a heterocyclic group which may be substituted, an aralkyl group which may be substituted, or an alkyl group substituted by a heterocyclic ring which may be substituted, or R.sup.1 and R.sup.2 may form a nitrogen-containing heterocyclic ring, which may be substituted, together with the adjacent nitrogen atoms, and R.sup.3 and R.sup.4 are the same or different from each other and independently represent a hydrogen atom, or an alkyl or aralkyl group, or a salt thereof, a preparation process thereof, and a medicine comprising such a derivative or salt as an active ingredient.

Abstract: Disclosed is a 2'-deoxy-5-fluorouridine derivative of the formula ##STR1## wherein one of R.sub.1 and R.sub.2 is a benzyl group which may optionally have substituent selected from the group consisting of C.sub.1 -C.sub.6 alkyl group, C.sub.1 -C.sub.6 alkoxy group, C.sub.1 -C.sub.3 halogenated alkyl group, halogen atom, hydroxyl group and nitro group on the phenyl ring, and the other constitutes an amino acid residue, or a salt thereof. The compounds are useful for treating cancer.