Anti-tumour agents

A quinazoline of the formula:

• ##STR33## wherein R.sup.1 is alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy or alkylthio each of up to 6 carbon atoms;
• aryl, aryloxy or arylalkyl each of up to 10 carbon atoms;
• halogeno, hydroxy, mercapto, pyridylthio or pyrimidinylthio;
• alkyl of up to 3 carbon atoms which bears one, two or three halogeno substituents or which bears one or two substituents selected from hydroxy, amino, pyridylthio, pyrimidinylthio, alkoxy, alkanoyloxy, alkylthio, alkylamino, dialkylamino and alkanoylamino each of up to 6 carbon atoms and aroyloxy and aroylamino each of up to 10 carbon atoms;
• or alkoxy of up to 3 carbon atoms which bears one or two substituents selected from hydroxy and alkoxy of up to 6 carbon atoms;
• wherein R.sup.2 is hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, mercaptoalkyl, alkylthioalkyl, halogenoalkyl, cyanoalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, alkanoylalkyl, carboxyalkyl, carbamoylalkyl or alkanoyl each of up to 6 carbon atoms or aroylalkyl of up to 10 carbon atoms;
• wherein Ar is phenylene, naphthylene or heterocyclene which is unsubstituted or which bears one or two substituents selected from halogeno, phenyl, cyano, nitro, hydroxy, amino and carbamoyl and alkyl, alkoxy, halogenoalkyl, alkanoylamino, alkylthio and alkoxycarbonyl each of up to 6 carbon atoms;
• and wherein R.sup.3 is such that R.sup.3 --NH.sub.2 is L-aspartic acid, L-glutamic acid, L-alanine, L-phenylalanine, L-serine, glycine, L-ornithine, L-2-aminobutyric acid or a poly-L-glutamic acid of the formula ##STR34## wherein m is an integer from 1 to 10;
• or a pharmaceutically - acceptable salt or ester thereof.