Reaction Steps
To a suspension of 4-cyano-1H-imidazole-2-carboxylic acid [2-(1,1-dioxo-1,2,3,6-tetrahydro-1λ6-thiopyran-4-yl)-4-piperidin-4-yl-phenyl]-amide trifluoroacetic acid salt (as prepared in Example 36, step (e), 62 mg, 0.115 mmol) in 4 mL of 1:1 DCM/DMF at RT was added DIEA (60 μL, 0.345 mmol). The mixture was stirred for 5 min, then acetic anhydride (11 μL, 0.121 mmol) was added slowly to the mixture, and the resulting mixture was stirred at RT for 0.5 h. Treated with 40 mL of EtOAc, the mixture was washed with H2O (2×20 mL). The aqueous layers were extracted with EtOAc (4×10 mL). The combined organic layers were concentrated in vacuo. The residue was purified by flash chromatography on silica gel (1-4% MeOH/DCM) yielding 50.9 mg (95%) of the title compound as a white solid. 1H-NMR (CDCl3; 400 MHz): δ 13.0 (s, 1H), 9.10 (s, 1H), 8.13 (d, 1H, J=8.4 Hz), 7.77 (d, 1H, J=2.3 Hz), 7.26 (dd, 1H, J=8.4, 2.0 Hz), 7.08 (d, 1H, J=2.0 Hz), 5.77 (t, 1H, J=4.3 Hz), 4.84 (dt, 1H, J=13.3, 2.1Hz), 4.00 (dt, 1H, J=13.3, 2.1 Hz), 3.89 (br s, 2H), 3.31 (t, 2H, J=6.2 Hz), 3.23 (td, 1H, J=13.2, 2.5 Hz), 3.02 (m, 2H), 2.77 (dddd, 1H, J=11.9, 11.9, 3.4, 3.4 Hz), 2.68 (ddd, 1H, J=12.6, 12.6, 2.9 Hz), 2.18 (s, 3H), 1.70-1.97 (m, 4H). Mass spectrum (ESI, m/z): Calcd. for C23H25N5O4S, 468.2 (M+H), found 468.1.
