The synthesis method of Methyl 1,2-dihydro-2-oxopyridine-4-carboxylate is as follows: Dissolve 10 g (0.066 mol) of m-nitrobenzaldehyde and 11 g (0.067 mol) of ethyl chloroacetate in 60 ml of benzene, and add 1 ml of piperidine. 1 ml of glacial acetic acid, heated in a water bath, and the water generated in the reaction was continuously removed with a Dean-start water separator. After refluxing for 3h, the benzene was evaporated, 20ml of ether was added to the residue, frozen, crystallized, suction filtered, and dried to give 16.2g of methyl 2-hydroxypyridine-4-carboxylate, yield 82%, mp 92 -96°C.
