N,N-Dimethylpropargylamine → 2-Chloro-4-(3-dimethylaminopropyn-1-yl)-benzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 4-bromo-2-chlorobenzoic acid, methyl ester (18.69 g) in triethylamine (110 ml), was added 1-dimethylamino-2-propyne (12.1 ml), bis(triphenylphosphine)palladium(II) chloride (1.26 g), and copper(I) iodide (0.136 g). The mixture was heated slowly to 60° C., and the temperature maintained for one hour. The reaction was cooled to room temperature, filtered through diatomaceous earth, and the collected solid washed with ethyl acetate. The solvent was removed in vacuo, the resulting residue redissolved in ethyl acetate, and washed with water (3×). The combined organic extract was dried over anhydrous sodium sulfate, and the solvent removed in vacuo to give a crude product. The crude product was purified by column chromatography on silica gel (225 g), eluting with 40% ethyl acetate/hexane. After removing the solvent in vacuo, the title compound was obtained as a viscous oil (17.7 g), MS (+FAB), m/z: 252 (M+H)+.

Provenance & Evidence