(1R,2R)-2-((6-((3H-Imidazo[4,5-b]pyridin-3-yl)methyl)benzo[d]thiazol-2-yl)amino)cyclohexanol from Example 3 (188 mg, 0.50 mmol) was stirred in a mixture of DCM/MeCN/DMA (4:4:2, v/v/v) at rt. Dess-Martin periodinane (254 mg, 0.60 mmol) was added and the mixture was stirred at rt for 30 min before another batch of periodinane (254 mg, 0.60 mmol) was added. The resulting mixture was heated at 55° C. for 4 h, then another batch of periodinane (254 mg, 0.60 mmol) was added and the reaction mixture was heated at 60° C. for 6 h. LCMS showed that the reaction was mostly complete. The mixture was then cooled to rt and partitioned between DCM and 3% aq NaOH, and then the organic layer was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 0-100% EtOAc in hexanes to give (R)-2-((6-((3H-imidazo[4,5-b]pyridin-3-yl)methyl)benzo[d]thiazol-2-yl)amino)cyclohexanone (150 mg, 80%) as a white solid. 1H NMR (300 MHz, DMSO-d6) δ 8.60 (s, 1H), 8.38 (dd, J=1.2, 4.8 Hz, 1H), 8.22 (d, J=7.3 Hz, 1H), 8.09 (dd, J=1.3, 8.1 Hz, 1H), 7.70 (d, J=1.1 Hz, 1H), 7.26-7.35 (m, 2H), 7.19-7.26 (m, 1H), 5.49 (s, 2H), 4.68 (td, J=6.5, 12.8 Hz, 1H), 2.53-2.67 (m, 1H), 2.42 (ddd, J=2.7, 5.9, 12.3 Hz, 1H), 2.30 (d, J=13.4 Hz, 1H), 1.94-2.12 (m, 1H), 1.82 (br s, 2H), 1.38-1.66 (m, 2H). LCMS (ESI) m/z 378 (M+H)+.
