A mixture of 6-((9H-purin-9-yl)methyl)-2-(methylsulfinyl)benzo[d]oxazole (106 mg, 0.34 mmol), (1R,2R)-2-aminocyclohexanol (77 mg, 0.51 mg) and DIEA (132 mg, 1.02 mmol) in DMA (3 mL) was stirred at 135° C. for 2 h. The reaction mixture was cooled to rt, poured into water (30 mL) and extracted with ethyl acetate (20 mL×2). 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 1:6 petroleum ether/ethyl acetate to give crude product, which was washed with 10:1 petroleum ether/ethyl acetate to afford (1R,2R)-2-((6-((9H-purin-9-yl)methyl)benzo[d]oxazol-2-yl)amino)cyclohexanol as a light yellow solid (68 mg, 48.57%). 1H NMR (300 MHz, DMSO-d6) δ 9.16 (s, 1H), 8.96 (s, 1H), 8.73 (s, 1H), 7.79 (d, J=7.8 Hz, 1H), 7.42 (s, 1H), 7.16 (d, J=1.2 Hz, 1H), 7.14 (d, J=8.1 Hz, 1H) 5.51 (s, 2H), 4.66 (d, J=4.2 Hz, 1H), 3.34 (br s, 2H), 1.90 (br s, 2H), 1.60 (br s, 2H), 1.22 (br s, 4H). LCMS (ESI) m/z 365 (M+H)+.
