H. Furrer, R. Wágner, H. Fehlhaber
Nov 1, 1994
Citations
0
Influential Citations
5
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
6-Benzyl-3-methyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione 2, a representative of new antithrombotic compounds with favourable cerebral and peripheral effects has been synthesized from enamine 1 in good yield by two methods. The thermal fusion of 1 with ureas gave the pyrido[4,3-d]-pyrimidine-2,4-diones 5a, 2 and 5b and unexpectedly the esters 6 and 7. The structure of 6 was deduced from its spectroscopic properties and was proven by ozonolysis to cleavage products 9 and 10 and by oxidative hydrolysis to pyrimidin-2-one 13. The (Z)-configured 6 was converted to (E)-configured 7 by methylation. The products 5a, 5b and 5c were synthesized by independent methods. Hydrogenolysis of 2 led to the secondary amine 15 which was alkylated to the base of 16.