A mixture of (3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-4-methyl-5-oxo-6-chloro-4,5-dihydro-imidazo(1,5-a)quinazoline (0.4 g, 1,2 mmol), benzyl alcohol (0.32 g, 3 mmol), and sodium hydride (55% dispension in oil, 0.13 g, 3 mmol) in 20 ml of dry DMF (dimethylformamide) was stirred for 5 h at 110° C., then cooled to room temperature and was thereafter poured into 30 ml of water and 5 ml of ether. The mixture was then stirred for 1 h at 0° C. and the precipitate was filtered off, rinsed with water and dried giving 0.26 g (53%) of 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-4-methyl-5-oxo-6-benzyloxy-4,5-dihydro-imidazo (1,5-a)quinazoline, M.p. 221°-224° C.
