Pyridine → N-[(6R)-6-[(benzyloxy)methyl]-8a-(5-bromo-2,4-difluorophenyl)-4,4a,5,6,8,8a-hexahydropyrano[3,4-d][1,3]thiazin-2-yl]benzamide

Participants

Reaction Conditions

Reaction Steps

A solution of C8 (0.964 g, 1.59 mmol) and pyridine (0.487 ml, 6.05 mmol) in dichloromethane (27.0 mL) was cooled to −50° C. internal temperature. Trifluoromethanesulfonic anhydride (0.535 mL, 3.18 mmol) was added drop-wise to the solution and the mixture was gradually warmed to 0° C. and allowed to stir at that temperature for 3.5 hours. The reaction mixture was partitioned between dichloromethane (250 mL) and water (250 mL). The organic layer was removed and washed with water (2×300 mL) and brine (1×250 mL), then dried over magnesium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (Gradient 0% to 50% ethyl acetate in heptane) provided the product as a white solid. Yield: 822 mg, 1.40 mmol, 88%. LCMS m/z 589.6 [M+H+], Br isotopic pattern. 1H NMR (400 MHz, CD3OD), characteristic peaks: δ 8.05-8.16 (m, 2H), 7.62 (t, J=7.9 Hz, 1H), 7.61-7.67 (m, 1H), 7.42-7.49 (m, 2H), 7.28-7.33 (m, 2H), 7.16-7.25 (m, 3H), 4.58 (d, J=11.7 Hz, 1H), 4.52 (d, J=11.7 Hz, 1H), 4.07 (dd, J=11.9, 1.6 Hz, 1H), 3.89 (br d, J=11.9 Hz, 2H), 3.54-3.62 (m, 2H), 3.11-3.18 (m, 1H), 2.96 (dd, J=13.2, 4.2 Hz, 1H), 2.74 (dd, J=13.2, 2.8 Hz, 1H), 1.88-1.98 (m, 1H), 1.69 (d, J=11.7 Hz, 1H).

Provenance & Evidence