To a solution of the product of Step B (3.47 g, 8.99 mmol, 1 eq) in DCM (40 mL) at rt was added HOBt hydrate (2.34 g, 15.3 mmol, 1.7 eq) and EDCI (2.58 g, 13.5 mmol, 1.5 eq). After 15 min, DIEA (7.8 mL, 45.3 mmol, 5 eq) and 3-(trifluoromethyl)-5,6,7,8-tetrahydro-1,6-naphthyridine-2 HCl (3.71 g, 13.5 mmol, 1 eq) were added and the solution stirred overnight at rt. Saturated NaHCO3 was added, the solution extracted with DCM, the organics combined, dried over MgSO4, and concentrated. Purification by chromatography (120 g column) eluting with 25 to 60% EtOAc/heptane afforded the title compound of Step C. 1H NMR (CHLOROFORM-d) δ: 8.71 (s, 1H), 7.69 (s, 1H), 6.19 (d, J=5.4 Hz, 1H), 5.76 (dd, J=5.6, 2.0 Hz, 1H), 4.68-4.86 (m, 4H), 3.85-4.07 (m, 2H), 3.54-3.65 (m, 2H), 3.13 (t, J=5.7 Hz, 2H), 2.58 (dd, J=13.3, 7.7 Hz, 1H), 1.98-2.16 (m, 2H), 1.85-1.97 (m, 1H), 1.42 (s, 9H), 0.84 (s, 9H), −0.02 (d, J=4.4 Hz, 6H). Calculated for C28H42F3N3O4Si: 570.3 (M+1). found: 570.3.
