反应详情

温度

90 °C

5-Nitro-2-(2-trifluoromethyl-phenyl)-pyridin-4-ylamine (749 mg, 2.65 mmol, prepared as in the previous step) was dissolved in concentrated HCl (12 mL) and heated to 90° C. SnCl2.2H2O (2.98 g, 13.2 mmol) was added to the stirred mixture in small portions and resulting mixture was stirred at 90° C. for 1 h. After completion of addition, the resulting mixture was cooled to 0° C. in an ice bath, treated with 6 M aqueous NaOH (30 mL) and then extracted with DCM (3×40 mL). The combined extracts were dried over MgSO4 and filtered. The solvent was removed under reduced pressure and the residue was chromatographed on a 40-g SiO2 pre-packed column eluting with 0:1-3:2 EtOAc/hexanes to yield 2-chloro-6-(2-trifluoromethyl-phenyl)-pyridine-3,4-diamine. 1H-NMR (400 MHz, CDCl3) δ: 7.67 (d, J=7.8 Hz, 1H), 7.47-7.55 (m, 1H), 7.37-7.46 (m, 2H), 6.57 (s, 1H), 4.09 (br s., 2H), 3.74 (br. s., 2H).

1. customresulting mixture
2. additionAfter completion of addition
3. temperaturethe resulting mixture was cooled to 0° C. in an ice bath
4. extractionextracted with DCM (3×40 mL)
5. dry with materialThe combined extracts were dried over MgSO4
6. filtrationfiltered
7. customThe solvent was removed under reduced pressure
8. customthe residue was chromatographed on a 40-g SiO2 pre-packed column
9. washeluting with 0:1-3:2 EtOAc/hexanes