A mixture of 6-(imidazo[2,1-b]thiazol-5-ylmethyl)-2-(methylsulfinyl)benzo[d]thiazole (310 mg, 0.93 mmol), (1R,2R)-2-aminocyclohexanol (321 mg, 2.79 mmol) and DIEA (240 mg, 1.86 mmol) in NMP (10 mL) was stirred for 1 d at 130° C. The mixture was cooled to rt and water (50 mL) was added. The mixture was extracted with EtOAc (100 mL×3). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 50:1 to 10:1 DCM/MeOH, and the product was further purified by preparative HPLC to afford (1R,2R)-2-((6-(imidazo[2,1-b]thiazol-5-ylmethyl)benzo[d]thiazol-2-yl)amino)cyclohexanol as a brown solid (100 mg, 28%). 1H NMR (300 MHz, DMSO-d6) δ 7.84 (d, J=7.2 Hz, 1H), 7.68 (d, J=4.5 Hz, 1H), 7.54 (d, J=1.8 Hz, 1H), 7.27 (d, J=8.1 Hz, 1H), 7.20 (dd, J=0.9, 4.2 Hz, 1H), 7.10 (dd, J=1.8, 8.4 Hz, 1H), 7.02 (s, 1H), 4.71 (d, J=4.8 Hz, 1H), 4.15 (s, 2H), 3.52-3.49 (m, 1H), 3.39-3.36 (m, 1H), 2.05-2.01 (m, 1H), 1.90-1.86 (m, 1H), 1.65-1.59 (m, 2H), 1.30-1.16 (m, 4H). LCMS (ESI) m/z 385 (M+H)+.
