GENERAL ROUTES TO 4-OXO-4H-PYRANO[2,3-B]PYRIDINE-3-CARBOXYLATES AND RELATED-COMPOUNDS - SYNTHESIS OF THE OXYGEN AND SULFUR ISOSTERES OF NALIDIXIC-ACID

Imidazolides of 2-hydroxy- and 2-mercaptonicotinic acids with LiCH2CO2Bu-t gave ketoesters which were cyclised with MeOCH=NMe2+ MeOSO3- and i-Pr2NEt or with (RCO)2O-NEt3-DMAP to the title 2-H or 2-R bicyclic esters; the corresponding 3-methylsulfonyl and 3-phosphonate analogs were similarly prepared...

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Bibliographic Details
Published inHeterocycles Vol. 35; no. 1; pp. 93 - 97
Main Authors MCCOMBIE, SW, LIN, SI, TAGAT
Format Journal Article
LanguageEnglish
Published OXFORD Elsevier 01.01.1993
Subjects
Chemistry
Chemistry, Organic
Physical Sciences
Science & Technology
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Summary:Imidazolides of 2-hydroxy- and 2-mercaptonicotinic acids with LiCH2CO2Bu-t gave ketoesters which were cyclised with MeOCH=NMe2+ MeOSO3- and i-Pr2NEt or with (RCO)2O-NEt3-DMAP to the title 2-H or 2-R bicyclic esters; the corresponding 3-methylsulfonyl and 3-phosphonate analogs were similarly prepared. The 2-unsubstituted 4-oxopyranopyridine-3-carboxylates were unstable at physiological pH, whereas the thio analogs were stable.
ISSN:0385-5414
DOI:10.3987/com-92-s35