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Conversion of 1‐benzyl‐4‐aminotetrahydropyridine‐3‐carboxylic acid methyl ester to antithrombotic pyrido[4,3‐ d ]pyrimidine‐2,4‐diones and to (2‐oxotetrahydropyrimidin‐4‐ylidene)acetic acid methyl esters
Author(s) -
Furrer H.,
Wagner R.,
Fehlhaber H.W.
Publication year - 1994
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570310649
Subject(s) - chemistry , hydrogenolysis , enamine , ozonolysis , pyrimidine , acetic acid , hydrolysis , yield (engineering) , antithrombotic , amine gas treating , lactam , organic chemistry , medicinal chemistry , stereochemistry , catalysis , materials science , metallurgy , medicine , cardiology
6‐Benzyl‐3‐methyl‐5,6,7,8‐tetrahydro‐1 H ‐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 .