m-Chloroperbenzoic acid → Ethyl 2-chloromethyl-4-(3,4-dimethoxyphenyl)-6,7-dimethoxyquinoline-3-carboxylate 1-oxide

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Reaction Steps

A mixture of 2-chloromethyl-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylic acid ethyl ester (3.0 g), m-chloroperbenzoic acid (85%, 2.3 g) and methanol (40 ml) was stirred under refluxing conditions for 2 hours. The reaction mixture was distilled under reduced pressure to remove the solvent. The residue was poured over chloroform. The chloroform layer was washed with water and dried (MgSO4), after which the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with chloroform-ethyl acetate (6:4, v/v) to yield 2-chloromethyl-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylic acid ethyl ester 1-oxide (2.0 g, 65%), which was then recrystallized from acetone-isopropyl ether to yield a colorless prismatic crystal having a melting point of 193° to 194° C.

Provenance & Evidence