1.6- dihydro-6-oxopyridine-2-carboxylic acid

Bossio R, Marcos CF, Marcaccini S, Pepino R (1997) Studies on isocyanides and related compounds. A novel synthetic route to 1, 6-dihydro-6-oxopyridine-2-carboxylic acid derivatives. Heterocycles 45 1589-1592... 

Natural product-related l,6-dihydro-6-oxopyridine-2-carboxylic acid derivatives originate from the reaction of aldehyde, amines, phenylglyoxylic acid and isocyanides [133]. 

Pyridonecarboxylic acid esters. F2 (diluted with N2) bubbled into a soln. of dimethyl pyridine-2,3-dicarboxylate in 2 1 acetonitrile/water for 20 min at 0 , flushed with N2 for 30 min at room temp., and refluxed for 2 h-+ dimethyl 1,6-dihydro-6-oxopyridine-2,3-dicarboxylate. Y 56%. F.e. inch oxidation of 2-, 3- and 4-carboxypyridines, and of methyl quinoline-4-carboxylate, s. M. Van Der Puy et al.. Tetrahedron Letters 29, 4389-92 (1988). 

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