Hydrochloric Acid → 4-(1-tert-Butoxycarbonyl-1,2,3,6-tetrahydropyridin-4-yl)benzoic acid

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Reaction Steps

In 1,2-dimethoxyethane (30 ml), 4-(1-tert-butoxycarbonyl-4-trifluoromethanesulfonyloxy-1,2,3,6-tetrahydropyridine (Synthesis, 993, 1991)(3.59 g) was dissolved, followed by the addition of 4-carboxyphenylboric acid (3.60 g), lithium chloride (1.38 g), tetrakistriphenylphosphine palladium (0.62 g) and an aqueous solution of sodium carbonate (2M, 16.3 ml). The resulting mixture was heated under reflux for 2 hours under an argon gas atmosphere. To the reaction mixture, 1N hydrochloric acid was added. The resulting mixture was extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate. The residue obtained by distilling off the solvent under reduced pressure was purified by chromatography on a silica gel column (dichloromethane˜dichloromethane:methanol=100:1). The purified product was pulverized and washed in a mixed solvent of hexane and ethyl acetate (hexane:ethyl acetate=5:1), whereby the title compound (462 mg, 14%) was obtained.

Provenance & Evidence