Reaction Steps
To a solution of tert-butyl ((4aR,7aR)-7a-(2-fluoro-5-(picolinamido)phenyl)-4a,5,6,7a-tetrahydro-4H-furo[2,3-d][1,3]thiazin-2-yl)carbamate (Preparation 5, 12 mg, 0.025 mmol) in dichloromethane (254 μL) was added TFA (39.1 μL, 0.508 mmol) at rt, and the reaction mixture was stirred at rt for 3 h. The crude product was directly purified by prep TLC eluting with 90% CH2Cl2/9% MeOH/1% NH4OH to give the title compound (5 mg, 0.013 mmol, 52.9% yield) a colorless oil. 1H NMR (500 MHz, CHLOROFORM-d) δ 10.04 (s, 1H), 8.68-8.62 (m, 1H), 8.31 (dt, J=7.8, 1.0 Hz, 1H), 8.01 (ddd, J=8.9, 4.1, 2.9 Hz, 1H), 7.93 (td, J=7.7, 1.7 Hz, 1H), 7.72 (dd, J=6.9, 2.8 Hz, 1H), 7.51 (ddd, J=7.5, 4.8, 1.1 Hz, 1H), 7.08 (dd, J=10.9, 8.8 Hz, 1H), 4.11 (t, J=7.2 Hz, 3H), 3.50 (s, 1H), 3.15 (dd, J=12.8, 4.0 Hz, 1H), 2.97 (ddd, J=13.0, 7.5, 1.8 Hz, 1H), 2.77 (dd, J=7.0, 4.0 Hz, 1H), 2.22-1.98 (m, 2H). MS (M−1): 371.2.
