78535-05-4 8-(Phenylmethoxy)-2-(1-piperazinyl)-4-(4-thiomorpholinyl)pyrimido(5,4-d)pyrimidine S-oxide 8-Benzyloxy-4-(1-oxido-thiomorpholino)-2-piperazino-pyrimido(5,4-d)pyrimidine Pyrimido(5,4-d)pyrimidine, 8-(phenylmethoxy)-2-(1-piperazinyl)-4-(4-thiomorpholinyl)-, S-oxide