Potassium trimethylsilanolate (970 mg, 7.6 mmol) was added in one portion in a stirred solution of methyl 2-methyl-2-(trans-4-{4-[({5-[(2,4,5-trifluorophenyl)amino]-1,3,4-oxadiazol-2-yl}carbonyl)amino]phenyl}cyclohexyl)propanoate (Example 623, 390 mg, 0.76 mmol) in THF (10 mL) and the reaction mixture was heated in the microwave at 90° C. for 20 min, then 100° C. for 1 h and finally at 120° C. for 30 min. The reaction mixture was concentrated in vacuo to leave a yellow solid and then a 1M aqueous solution of citric acid (40 mL) was added and the mixture was stirred for 30 mins. The mixture was filtered to leave a solid. The solid was washed with H2O (20 mL) and purified by recrystallisation, using ethanol as solvent, to give the title compound (219 mg, 57%) as a white solid; 1H NMR δ 1.06 (6H, s), 1.12-1.27 (2H, m), 1.37-1.5 (2H, m), 1.58-1.75 (3H, m), 1.8-1.9 (2H, m), 2.39-2.5 (1H, m), 7.22 (2H, m), 7.65 (2H, m), 7.68-7.78 (1H, m), 8.14-8.24 (1H, m), 11.0 (1H, s), 11.13 (1H, s), 12.1 (1H, s); MS m/e MH+ 502.
