Ammonium Acetate → 3-Aminomethylene-6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydro-1-quinoline carboxylic acid, benzyl ester

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Reaction Steps

A mixture of 5.0 g. of 3-hydroxymethylene-6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydro-1-quinoline carboxylic acid, benzyl ester and 5.0 g. of ammonium acetate in 200 ml. of ethanol is heated to reflux for 35 min. The reaction mixture is concentrated to dryness and the residue taken up in 200 ml. of chloroform. The chloroform solution is then washed successively with water (1 × 100 ml.), 1N aqueous sodium hydroxide (2 × 100 ml.) and brine (1 × 100 ml.), dried over magnesium sulfate and concentrated to dryness. The residual oil is crystallized from ethyl acetate, 3.34 g., m.p. 143°-149.5°C. and 1.3 g. recrystallized from the same solvent, 660 mg., m.p. 144°-146.5°C.

Provenance & Evidence