1961 年 81 巻 2 号 p. 182-185
Ethyl 6-methylnicotinate 1-oxide was prepared by oxidation of the ethyl group alone in 2-methyl-5-ethylpyridine by treatment with conc. nitric acid and selenium dioxide, followed by esterification and oxidation with hydrogen peroxide in glacial acetic acid. The nicotinate oxide was derived to 1-methoxylated quaternary salt by treatment with dimethyl sulfate and reacted with potassium cyanide in ethanol-water mixture to form ethyl 4-cyano-6-methylnicotinate, which was derived to dimethyl 6-methylcinchomeronate 1-oxide by hydrolysis, esterification, and oxidation with hydrogen peroxide in glacial acetic acid. This oxide was reacted with phosphoryl chloride at 120° to form dimethyl 2-chloro-6-methylcinchomeronate, which was hydrolyzed with acetic acid-sodium acetate and esterified to form dimethyl 2-oxo-6-methyl-1, 2-dihydrocinchomeronate. Reaction of this salt with ammonia in methanol and reaction of its product diamide with phosphoryl chloride in pyridine finally afforded 3, 4-dicyano-6-methyl-2(1H)-pyridone, an intermediate material for the synthesis of cobalamine.