2-Ketoalkyl-4(3H)-quinazolinones of the formula ##STR1## wherein R.sub.1 is an aliphatic, cycloaliphatic or hydrocarbon aromatic group of 1-10 carbon atoms; A is divalent alkylene of 1 to 10 carbon atoms; R.sub.2 is an aliphatic, cycloaliphatic, hydrocarbon aromatic or heterocyclic group of 1-10 carbon atoms formed by condensing an acyl ester of the formula R.sub.2 COOR' which can be dissociated to form --COR.sub.2 and R'OH in which R' is the alcoholic portion of said ester; and R.sub.3 and R.sub.4 are each hydrogen, hydroxy, amino, halogen, trifluoromethyl, alkyl, alkoxy, alkylthio or alkylsulfonyl each of 1-4 carbon atoms, the substituents other than hydrogen when present being preferably in the 6- and/or 7-position of the quinazolinone nucleus provide compounds having useful activity as CNS depressants and anticonvulsants. A process is provided for preparing such compounds by ester condensation of a corresponding 2-alkyl-3-substituted-4(3H) quinazolinone with a condensable ester and excess sodium hydride in the presence of a strong ionization solvent such as refluxing 1,2-dimethoxyethane.