Oxalyl chloride → (4-Bromomethyl-2-phenylbenzoyl)methionine methyl ester

Participants

Reaction Steps

To a solution in dichloromethane (25 mL) of 4-bromomethyl-2-phenylbenzoic acid (2.16 g, 7.42 mmol), prepared as in Example 234B, was added oxalyl chloride (0.84 mL, 965 mmol) and 2 drops on DMF and the reaction mixture was stirred for 2 hours. The reaction mixture was concentrated in vacuo and azeotroped with toluene. The residue was dissolved in dichloromethane (15 mL) and then was added to a solution in dichloromethane (15 mL) of methionine methyl ester hydrochloride (1.78 g, 8.90 mmol) and diisopropylethylamine (3.10 g, 17.81 mmol) (prepared at −10° C.) dropwise. The reaction mixture was stirred for 30 minutes and then was poured into ether and extracted with water, aqueous 3N HCl (2×) and brine, dried, filtered and concentrated in vacuo. Chromatography on silica gel (5% ethyl acetate-chloroforn) to give (4-bromomethyl-2-phenylbenzoyl)methionine methyl ester (2.42 g, 75%).

Provenance & Evidence