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 (PBr3) (1.0 g) was added drop by drop to a solution of 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2-(2-hydroxyethyl)-quinoline-3-carboxylic acid ethyl ester (1.7 g) in benzene (50 ml) at room temperature. After stirring at 80° C. for 1 hour, the reaction mixture was poured over ice water, neutralized with a saturated aqueous solution of sodium hydrogen carbonate and then extracted with chloroform. The chloroform layer was washed with water and then dried (MgSO4), after which the solvent was distilled off. The residue was subjected to silica gel column chromatography and eluted with chloroform-ethyl acetate (1:1, v/v) to yield 2-(2-bromoethyl)-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylic acid ethyl ester (0.49 g, 26%), which was then recrystallized from ethyl acetate-hexane to yield a colorless prismatic crystal having a melting point of 132 to 133° C.

Provenance & Evidence