Methyl bromoacetate (0.07 ml, 0.78 mmol) was added to 250 mg (0.78 mmol) of 4-Amino-2-Ethyl-α-oxo-1-(phenylmethyl)-1H-indole-3-Acetamide in 4 ml of DMF, stirred at 60° C. for 0.5 hour, and then at room temperature for 20 hours. The mixture was diluted with water and extracted with EtOAc. The EtOAC solution was washed with brine, dried over MgSO4, and evaporated in vacuo. The residue was chromatographed over silica gel eluting with Hexane/50 to 100% EtOAc to give 196 mg (64%) of [[3-(Aminooxoacetyl)-2-ethyl-1-(phenylmethyl)-1H-indol-4-yl]amino]acetic acid methyl ester melting at 188-193° C.
