Triethylamine (2.5 ml, 1.81 mmol) was added to the suspension of {4-[3,5-bis-(4-cyano-phenoxy)-benzoylamino]-cyclohexyl}-carbamic acid tert-butyl ester (1.0 g, 1.81 mmol) in 15 ml of ethanol at 55° C. O-methyl-hydroxylamine hydrochloride solution (0.91 g in 3 ml of water (30% w/w)) and mercaptoacetic acid (0.51 ml, 7.24 mmol) were added to the reaction mixture at 55° C. under inert nitrogen atmosphere. Reaction mixture was stirred under nitrogen atmosphere at 90° C. for 40 h. After reaction completion, solvent was removed under vacuo and the residue was poured into ice-water to obtain white solid product which was filtered off and washed with water and hexane to afford 0.7 g of the required product. Percentage purity (LCMS): 69.3%, (M+1)=646+1.
