4-[3-[1(S)-(4-Chlorophenyl)ethyl]-1-(4-cyclohexylphenyl)ureidomethyl]benzoic acid methyl ester (35.0 g, 69.3 mmol) was dissolved in ethanol (400 mL). 4 N aqueous sodium hydroxide (100 mL) was added and the clear solution was stirred at room temperature for 3 hours. The solution was neutralised with 4 N hydrochloric acid (100 mL), and placed upon an ice bath to initiate crystallization. The crystals were collected, washed extensively with water, and dried in vacuo overnight. Yield: 34.25 g (100%).
