Abstract: [ 3H]-Imidazo[ 5,1-d] -1,2,3,5-tetrazin-4-one derivatives of the formula: ##STR1## wherein R.sup.1 represents hydrogen, or an alkyl, alkenyl or alkynyl group containing up to 6 carbon atoms, each such group being unsubstituted or substituted by from one to three substituents selected from halogen atoms, alkoxy, alkylthio, alkylsulphinyl and alkylsulphonyl groups containing up to 4 carbon atoms, and optionally substituted phenyl groups, or R.sup.1 represents a cycloalkyl group containing from 3 to 8 carbon atoms, and R.sup.2 represents a carbamoyl group optionally N-substituted by one or two groups selected ftom alkyl and alkenyl groups containing up to 4 carbon atoms, and cycloalkyl groups containing 3 to 8 carbon atoms, are new therapeutically useful compounds possessing antineoplastic and immunomodulatory activity.

Abstract: Benzophenone derivatives of the formula: ##STR1## wherein R.sup.1 is isopropyl, t-butyl or 2-phenylethyl, R.sup.2 is methyl or chlorine, n is 1 or 2 and m is 0, 1 or 2, are new compounds possessing pharmacological properties especially indicative of utility in the treatment of migraine.