反应详情

A stirred solution of 1-(1-(tert-butyldimethylsilyloxy)-2-methylpropan-2-yl)-6-oxo-1,6-dihydropyridine-3-carboxylic acid (2980 mg, 9.15 mmol), DIPEA (3198 μl, 18.3 mmol), diphenylphosphoryl azide (3.97 mL, 18.3 mmol), and t-butanol (8.60 mL, 9.15 mmol) in Dioxane (10 mL) was heated to reflux under nitrogen for 21 h. The reaction mixture was concentrated under reduced pressure and was purified on silica (80 g) eluting with 10-30% EtOAc/hexane. MS (ESI pos. ion) m/z (MH+): 397. Calc'd exact mass for C20H36N2O4Si: 396. 1H NMR (400 MHz, Chloroform-d) δ ppm −0.04 (s, 6 H) 0.81 (s, 9H) 1.49 (s, 9H) 1.63 (s, 6 H) 4.03 (s, 2 H) 5.98 (s, 1 H) 6.41 (d, J=9.54 Hz, 1 H) 7.15 (dd, J=9.54, 2.51 Hz, 1 H) 7.79 (br. s., 1 H).

1. temperatureto reflux under nitrogen for 21 h
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. customwas purified on silica (80 g)
4. washeluting with 10-30% EtOAc/hexane