Pyrimidine derivatives for enhancing antitumor activity

A compound of the formula ##STR29## or the pharmaceutically acceptable acid addition salt thereof wherein M is hydrogen, alkoxy having one to three carbon atoms, alkyl having one to three carbon atoms or benzyl optionally substituted by one or two alkoxy substituents each having one to three carbon atoms, amino, alkylamino having one to three carbon atoms, dialkylamino having two to six carbon atoms, fluoro, chloro or trifluoromethyl;

• M.sup.1 is hydrogen, amino, alkylamino having one to three carbon atoms, dialkylamino having two to six carbon atoms, alkyl having one to three carbon atoms, fluoro or chloro;
• R.sub.1 is aralkyl of the formula ##STR30## wherein n is an integer of 0 or 1, W is O, S or a chemical bond, A is alkylene having one to four carbon atoms, Y and Y.sup.1 are each hydrogen, alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms, fluoro, chloro, trifluoromethyl, amino, alkylamino having one to three carbon atoms or dialkylamino having two to six carbon atoms and Y and Y.sup.1 when taken together are ethylenedioxy or methylenedioxy;
• R.sub.2 is hydrogen or alkyl having one to eight carbon atoms;
• R.sub.1 and R.sub.2 when taken together with the nitrogen atom to which they are attached form a moiety of the formula ##STR31## wherein R.sub.5 is hydrogen, alkyl having one to three carbon atoms or dialkoxyphenylalkyl said alkoxy having one to three carbon atoms and said alkyl having from one to three carbon atoms, Q and Q.sup.1 are each hydrogen, alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms, fluoro, chloro, amino, alkylamino having one to three carbon atoms, trifluoromethyl or dialkylamino having two to six carbon atoms and Q and Q.sup.1 taken together are methylenedioxy or ethylenedioxy;
• R.sub.3 is aralkyl of the formula ##STR32## wherein m is an integer of 0 or 1, Z is 0, S or a chemical bond, B is alkylene of one to four carbon atoms, X and X.sup.1 are each hydrogen, alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms, fluoro, chloro, trifluoromethyl, amino, alkylamino having one to three carbon atoms or dialkylamino having two to six carbon atoms and X and X.sup.1 taken together are methylenedioxy or ethylenedioxy;
• R.sub.4 is hydrogen or alkyl having one to four carbon atoms;
• and R.sub.3 and R.sub.4 when taken together with the nitrogen atom to which they are attached form a moiety of the formula ##STR33## wherein P and P.sup.1 are each hydrogen, alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms, fluoro, chloro, trifluoromethyl, amino, alkylamino having one to three carbon atoms or dialkylamino having two to six carbon atoms, P and P.sup.1 when taken together are methylenedioxy or ethylenedioxy and R.sub.6 is hydrogen or dialkoxybenzyl said alkoxy having one to three carbon atoms.