反应详情

To a solution of imidodicarbonic acid, 4-(3-((tert-butoxycarbonyl)amino)-6-(4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate, 1,3-bis(1,1-dimethylethyl) ester (12.1 g, 20.66 mmol) in THF (68.9 mL) was slowly added LiHMDS (1 M in THF) (22.73 mL, 22.73 mmol) at −78° C. After stirring for 30 min, triethylchlorosilane (3.67 mL, 21.69 mmol) was added. The reaction mixture was warmed to room temperature and stirred for 1 h. Saturated sodium bicarbonate solution was added, and the mixture was extracted with EtOAc. The organic layer was washed well with water and brine, dried over anhydrous NaHCO3, filtered off, and concentrated in vacuo. The crude product was purified by flash chromatography eluting with 5% of EtOAc/heptane to provide imidodicarbonic acid, 4-(3-((tert-butoxycarbonyl)amino)-6-(4-((triethylsilyl)oxy)cyclohex-3-en-1-yl)pyrazin-2-yl)-2-fluorobenzoate, 1,3-bis(1,1-dimethylethyl) ester (12.1 g, 17.29 mmol). LCMS (m/z, neutral-nonpolar method): 701.8 (MH+), 1.14 min; 1H NMR (400 MHz, CDCl3) δ ppm 8.41 (s, 1H), 8.00-7.88 (m, 1H), 7.57-7.46 (m, 2H), 4.97 (br. s., 1H), 3.16-3.00 (m, 1H), 2.49-2.38 (m, 2H), 2.38-2.23 (m, 1H), 2.19-1.94 (m, 3H), 1.61 (s, 9H), 1.33 (s, 18H), 1.06-0.94 (m, 8H), 0.77-0.64 (m, 6H).

1. customat −78° C
2. stirringstirred for 1 h
3. extractionthe mixture was extracted with EtOAc
4. washThe organic layer was washed well with water and brine
5. dry with materialdried over anhydrous NaHCO3
6. filtrationfiltered off
7. concentrationconcentrated in vacuo
8. customThe crude product was purified by flash chromatography
9. washeluting with 5% of EtOAc/heptane