Analogifremgangsmåde til fremstilling af 2-merkapto-pyrido[2,3-d]pyrimidin-4(3H)-on derivater eller salte deraf

1,272,060. 2 - Mercapto - pyrido [2,3 - d]- pyrimidine-4(3H)-one derivatives. BOEHRINGER MANNHEIM G.m.b.H. 9 Dec., 1970 [11 Dec., 1969; 21 July, 1970], No. 58467/70. Heading C2C. Novel compounds I (including salts thereof) where R is C 1-5 alkyl, C 2-5 alkenyl, aralkyl or aryl optionally substituted by one or two OH, alkoxy, CO 2 H, carboalkoxy or amino-carbonyl, are made by partial hydrolysis of 2,4-di-SR- pyrido[2,3-d]pyrimidines or by reacting II with R-Y (one of the symbols X and Y is mercapto and the other is a reactive ester group); functional groups in the substituent R can be converted into OH, alkoxy, CO 2 H, carboalkoxy or aminocarbonyl. 2,4-Bis-methylmercaptopyrido- [2,3-d] pyrimidine is also prepared. Pharmaceutical preparations having natriuretic and diuretic action contain (I) as active ingredient; administration may be enterally or parenterally.