2-Phenylglycine → 2-(4-Chlorobutanamido)-2-phenylacetic acid

2-Amino-2-phenylacetic acid (1.00 g, 6.62 mmol) and TEA (2.77 ml, 19.8 mmol) were dissolved in a mixture of dioxane (13.2 ml) and water (13.2 ml). The mixture was cooled at 0° C. with an ice-bath and 4-chlorobutanoyl chloride (814 μl, 7.28 mmol) was added dropwise. The mixture was stirred at the same temperature for 1 hour and then dioxane was evaporated. The aqueous solution was acidified with 1N HCl and then was extracted three times with EtOAc (20 ml×3). The organic phase was dried (Na2SO4) and evaporated. The crude pale yellow oil was purified by flash chromatography (DCM/MeOH=9/1) and the collected compound was triturated with Et2O (about 15 ml) to obtain the title compound (658 mg, 38.9% yield) as a white solid.