反应详情

To a solution of 0.8 g (1.7 mmol) ethyl(2-{(tert-butoxycarbonyl)[2,2-difluoro-2-(2-pyridinyl)ethyl]amino}-5-chloro-3-fluoro-4-pyridinyl)acetate 1-6 in 3 mL 1,2-dichloroethane was added 0.44 g (1.8 mmol, 70% by weight) m-chloroperoxybenzoic acid. The reaction mixture was stirred at room temperature 16 h, heated to 60° C. 2 h, cooled, diluted with 300 mL EtOAc, washed with 200 mL 0.1M NaOH, and 200 mL brine. Dried over Na2SO4, filtered, and concentrated. Purification by automated flash chromatography (40 g silica cartridge, linear gradient 1-10% MeOH/CH2Cl2 over 25 min, 40 mL/min flow rate) followed by repurification of the mixed fractions by traditional silica gel chromatography (2×15 cm silica gel, linear gradient 2-5% MeOH/CH2Cl2) afforded ethyl(2-{(tert-butoxycarbonyl)[2,2-difluoro-2-(1-oxido-2-pyridinyl)ethyl]amino}-5-chloro-3-fluoro-4-pyridinyl)acetate 1-7. 1H NMR (400 mHz, CDCl3) δ8.20 (s, 1H); 8.18 (br d, 1H, J=5 Hz); 7.57 (br dd, 1H, J=7.7 and 2 Hz); 7.31 (br m, 2H); 5.0 (br m, 2H); 4.19 (q, 2H, J=7.14 Hz); 3.82 (s, 2H); 1.28 (s, 9H); 1.25 (t, 3H, J=7.14 Hz). Mass spectrum (electrospray) M+H=490.1

1. temperatureheated to 60° C
2. temperature2 h, cooled
3. washwashed with 200 mL 0.1M NaOH, and 200 mL brine
4. dry with materialDried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customPurification by automated flash chromatography (40 g silica cartridge, linear gradient 1-10% MeOH/CH2Cl2 over 25 min, 40 mL/min flow rate)
8. customfollowed by repurification of the mixed fractions by traditional silica gel chromatography (2×15 cm silica gel, linear gradient 2-5% MeOH/CH2Cl2)