反应详情

A solution of 1,1-dimethylethyl 4-[({6-[2-fluoro-4-(methylsulfonyl)phenyl]-3-pyridinyl}oxy)methyl]-1-piperidinecarboxylate (0.15 g, 0.32 mmol) in CH2Cl2 (10 mL) was treated with TFA (0.3 mL). The mixture was stirred at ambient temperature overnight. CH2Cl2 and excess of TFA were removed under reduced pressure. The residue was redissolved in CH2Cl2 (5 mL) and cooled in an ice bath. Diisopropylethylamine (1.5 mL) was added, followed by addition of methyl oxalyl chloride (34 μL, 0.36 mmol). The reaction mixture was allowed to warm up to ambient temperature and stirred overnight, quenched with aqueous NaHCO3 and extracted with EtOAc (50 mL×2). The combined organic extract was washed with brine and dried over Na2SO4, filtered, and the filtrate was concentrated to a viscous brown oil. The crude material was purified by chromatography on a silica gel column eluted with 1:5 acetone/CH2Cl2 to give 0.112 g (77%) of the title compound as a white solid. 1H NMR (400 MHz, CDCl3): δ 8.42 (d, 1H, J=2.9 Hz), 8.23 (t, 1H, J=7.8 Hz), 7.85-7.80 (m, 2H), 7.73 (dd, 1H, Ja=10.3 Hz, Jb=1.5 Hz), 7.27 (dd, 1H, Ja=10.8 Hz, Jb=2.9 Hz), 4.65-4.55 (m, 1H), 4.00-3.90 (m, 2H), 3.88 (s, 3H), 3.80-3.70 (m, 1H), 3.25-3.10 (m, 1H), 3.09 (s, 3H), 2.80-2.70 (m, 1H), 2.25-2.10 (m, 1H), 200-1.90 (m, 2H), 1.50-1.35 (m, 2H); LRMS (APCI), m/z 451 (M+H).

1. customCH2Cl2 and excess of TFA were removed under reduced pressure
2. dissolutionThe residue was redissolved in CH2Cl2 (5 mL)
3. temperaturecooled in an ice bath
4. additionDiisopropylethylamine (1.5 mL) was added
5. temperatureto warm up to ambient temperature
6. stirringstirred overnight
7. customquenched with aqueous NaHCO3
8. extractionextracted with EtOAc (50 mL×2)
9. extractionThe combined organic extract
10. washwas washed with brine
11. dry with materialdried over Na2SO4
12. filtrationfiltered
13. concentrationthe filtrate was concentrated to a viscous brown oil
14. customThe crude material was purified by chromatography on a silica gel column
15. washeluted with 1:5 acetone/CH2Cl2