A number of 3-(dialkylamino)-1H-pyrimido [1, 2-a] quinolin-1-ones 3 and 2-(dialkylamino)- 4H-pyrimido [2, 1-a] iso-quinolin-4-ones 4 were prepared by treating the corresponding chloro derivatives with an excess of dialkylamines. The highest in vitro antiplatelet activity was obtained when the dialkylamino substituent was 1-piperazinyl (compounds 3g and 4e). The novel 2-(1-piperazinyl)-4H-pyrido [1, 2-a] pyrimidin-4-one 2a was also prepared by an ...
