GB1051218A

USPTO Abstract

1,051,218. Pyrimido[5,4-d]pyrimidines. DR. KARL THOMAE G.m.b.H. March 9, 1964 [March 9, 1963], No. 9865/64. Heading C2C. Novel compounds of the Formula II wherein at least one of the symbols R 1 to R 3 represents a basic nitrogen-containing group linked via a nitrogen atom thereof to the pyrimido[5,4-d]- pyrimidine ring; and any remaining R 1 to R 3 represent free or substituted hydroxy groups, hydrogen atoms (in the case of R 1 and R 3 only) or halogen atoms (in the case of R 1 and R 2 only); and wherein A and A 1 represent hydrogen atoms, and acid addition salts thereof, are prepared by selectively reducing a compound of the Formula I wherein R 4 represents a basic nitrogen containing group linked via a nitrogen atom thereof to the C(4) carbon atom or a free or substituted hydroxy or mercapto group. Pyrimido[5,4-d]pyrimidines of the Formula II wherein the two symbols A and the two symbols A 1 together represent single bonds may be prepared by oxidizing compounds of the Formula II wherein A and A 1 represent hydrogen atoms. Therapeutic compositions with cardio-vascular, spasmolytic, diuretic and central nervous system activities, in the form of capsules, tablets, coated tablets, suspensions, drop solutions, ampoules, and suppositories for oral, parenteral and topical application, comprise compounds of the Formula II wherein A and A 1 represent hydrogen atoms, or non-toxic acid addition salts thereof, with a pharmaceutical carrier or excipient.