process for the production of 6.7 - the other ingredients are - 1.5 - 2.1 - b - dihydroimidazo chinazolin - 2 (3h) - on

摘要

III. The known blood platelet antiaggregative agent 6,7-dichloro-1,5-dihydroimidazo¢2,1-b!quinazolin-2(3H)-one is prepared in high yield via an improved process involving a novel intermediate of the Formula III in which R1 is (lower)alkyl and X is bromo, chloro, or iodo.