反应详情

To a solution of tert-butyl 2-cyanoacetate (523 mg, 3.71 mmol) in THF (15 mL) was added K2CO3 (854 mg, 6.18 mmol). Then 2-chloro-5-nitro-3-(trifluoromethyl)pyridine (700 mg, 3.09 mmol) was added into the mixture and the mixture was at 50° C. for 10 h. Then the solution was concentrated and distributed between EA and saturated NaHCO3 solution. The combined organic extract was washed with brine, dried over MgSO4, filtered and concentrated. The crude material was purified by preparative TLC (DCM/MeOH=20:1, Rf=0.4) to yield a light yellow solid of tert-butyl 2-cyano-2-(5-nitro-3-(trifluoromethyl)pyridin-2-yl)acetate (1 g, 3.02 mmol, 98.0% yield): 1H NMR (400 MHz, CD3OD) δ 8.99 (d, J=2.43 Hz, 1H), 8.36 (d, J=2.43 Hz, 1H), 3.35 (s, 1H), 1.49 (d, J=1.54 Hz, 9H); ES-LCMS m/z 276 (M-55).

1. concentrationThen the solution was concentrated
2. extractionThe combined organic extract
3. washwas washed with brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude material was purified by preparative TLC (DCM/MeOH=20:1, Rf=0.4)