Ammonium Chloride → 1,2,3,4-Tetrahydro-6-methoxy-3-(methoxycarbonyl)-2-oxo-4-quinoline acetic acid, methyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred, chilled (0° C.) suspension of crude 3-[[2-[(methoxycarbonyl)ethenyl]-4-methoxyphenyl]amino]-3-oxopropanoic acid, ethyl ester from step 3 in 700 ml of methanol was added, dropwise, a solution of 66.5 g of sodium methoxide (25% in methanol) in 250 ml of methanol. The resulting mixture was heated to reflux over 0.75 hour, cooled to 0° C., and poured into a cold saturated ammonium chloride solution. The aqueous layer was extracted with dichloromethane and the combined organic layers were washed with 10% hydrochloric acid solution and saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and concentrated to afford 1,2,3,4-tetrahydro-6-methoxy-3-(methoxycarbonyl)-2-oxo-4-quinoline acetic acid, methyl ester.

Provenance & Evidence