4,8-dimorpholin-4-ylpyrimido[5,4-d]pyrimidine HOMOPURINE,4,8-DIMORPHOLINO InChI=1/C14H18N6O2/c1-5-21-6-2-19(1)13-11-12(16-9-17-13)14(18-10-15-11)20-3-7-22-8-4-20/h9-10H,1-8H pyrimido[5,4-d]pyrimidine, 4,8-di-4-morpholinyl-