Phosphorus tribromide → Ethyl 2-(2-bromoethyl)-4-(3,4-dimethoxyphenyl)-6,7-dimethoxyquinoline-3-carboxylate

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Reaction Conditions

Reaction Steps

Phosphorus tribromide (1.0 g) was added dropwise to a solution of ethyl 4-(3,4-dimethoxyphenyl)-2-(2-hydroxyethyl)-6,7-dimethoxyquinoline-3-carboxylate (1.7 g) in benzene (50 ml) at room temperature. The mixture was stirred at 80° C. for 1 hour, poured into ice-cold water, neutralized with an aqueous saturated solution of sodium bicarbonate, and then extracted with chloroform. The chloroform layer was washed with water, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was subjected to column chromatography on silica gel. The fractions eluted with chloroform-ethyl acetate (1:1, v/v) gave ethyl 2-(2-bromoethyl)-4-(3,4-dimethoxyphenyl)-6,7-dimethoxyquinoline-3-carboxylate (0.49 g, 26%). This was recrystallized from ethyl acetate-hexane. Colorless prisms, mp. 132°-133° C.

Provenance & Evidence