4-(1-Oxido-thiomorpholino)-8-(2-phenylethylthio)-2-piperazino-pyrimido(5,4-d)pyrimidine 77749-81-6 Pyrimido(5,4-d)pyrimidine, 8-((2-phenylethyl)thio)-2-(1-piperazinyl)-4-(4-thiomorpholinyl)-, S-oxide RX-RA 85