treatment of 1,2-dihydro-1-hydroxy-2-oxopyridine-6-carboxylic acid ( 5 ) with phosgene in thf solution gives the active ester poly [ 1,2-dihydro-1,2-dioxopyridine-6-carboxylate ] , which upon treatment with excess anhydrous dimethylamine gave a 60 % yield of n , n-dimethyl-1,2-dihydro-1-hydroxy-2-oxopyridine-6-carboxamide ( 6 ) .
C0007066
carboxylic acid
C0014898
ester