A solution of PyBOP (211 mg, 0.406 mmol) and 5-(tert-butoxycarbonylamino)-2-(2,6-difluoro-3-methoxyphenyl)thiazole-4-carboxylic acid (118 mg, 0.31 mmol) in DCM (3 mL) was stirred at room temperature for 30 min. A solution of tert-butyl (1-(4-amino-1-methyl-1H-pyrazol-5-yl)piperidin-4-yl)methylcarbamate (89 mg, 0.29 mmol) and DIPEA (81 μL, 0.46 mmol) in DCM (3 mL) was added and the mixture stirred at room temperature for 16 hr. The mixture was diluted with DCM and washed with water. The organic layer was separated, passed through a phase separation cartridge and concentrated under reduced pressure. The residue was purified via silica gel column chromatography (0-100% EtOAc/isohexane). The isolated intermediate was re-dissolved in DCM (10 mL) and TFA (2 mL) added. The mixture was stirred at room temperature for 3 hr. The mixture was concentrated under reduced pressure and the residue purified by preparative HPLC to yield 354 as a white solid (31 mg, 42%). 1H NMR (400 MHz, d4-MeOD) δ 7.58 (s, 1H), 7.37-6.99 (m, 1H), 7.06 (t, J=10.0 Hz, 1H), 3.93 (s, 3H), 3.73 (s, 3H), 3.29-3.04 (m, 4H), 2.65 (d, J=6.5 Hz, 2H), 1.85 (d, J=12.4 Hz, 2H), 1.70-1.42 (m, 1H), 1.48-1.21 (m, 2H). LCMS (ES+) m/z 478 (M+1).
