Triethylamine → 2,6-Dimethyl-4-[[[3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]benzyl]amino]carbonyl]benzoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of trifluoromethanesulfonic acid, 2,6-dimethyl-4-[[[[3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]phenyl]methyl]amino]carbonyl]phenyl ester (Example 23; 3.02 g, 5.83 mmol) in acetonitrile (49 mL) and water (7 mL) at 25° C. was added palladium (II) acetate (196 mg, 0.874 mmol), 1,3-bis(diphenylphosphino)propane (360 mg, 0.873 mmol), followed by triethylamine (2.03 mL, 14.5 mmol). The reaction was then pressurized to 40 psi with carbon monoxide and heated to 80° C. for 4 h. The mixture was diluted with ethyl acetate (300 mL) and washed with water (100 mL) containing 1 mL of triethylamine. The water layer was reextracted with ethyl acetate (2×50 mL) and the combined ethyl acetate layers were discarded. The water layer was acidified with 1 N HCl to pH 2, and extracted with ethyl acetate (200 mL). The ethyl acetate layer was washed with water (50 mL) and brine (50 mL), dried (MgSO4), filtered and concentrated to yield 2,6-dimethyl-4-[[[[3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]phenyl]methyl]amino]carbonyl]benzoic acid (1.7 g, 71%) as a white solid.

Provenance & Evidence