反应详情

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%).

1. concentrationThe reaction mixture was concentrated in vacuo
2. customazeotroped with toluene
3. dissolutionThe residue was dissolved in dichloromethane (15 mL)
4. stirringThe reaction mixture was stirred for 30 minutes
5. extractionextracted with water, aqueous 3N HCl (2×) and brine
6. customdried
7. filtrationfiltered
8. concentrationconcentrated in vacuo