反应详情

A solution of sodium nitrite (21.67 g, 314.13 mmol) in water (150 mL) was added dropwise to a stirred mixture of 5-bromo-6-fluoropyridin-2-amine (50 g, 261.78 mmol) and sulphuric acid (1.2 mL, 22.51 mmol) in water (750 mL) at 0-5° C. The resulting suspension was stirred for 48 h at ambient temperature then the precipitate collected by filtration, washed with water (200 mL) and dried under vacuum to afford the desired material (40.0 g, 80%) as a pale yellow solid, which was used without further purification. NMR Spectrum: 1H NMR (300 MHz, DMSO-d6) δ 6.55 (1H, d), 8.00 (1H, t), 11.71 (1H, bs). Mass Spectrum: m/z (ES+)[M+H]+=192.

1. filtrationthe precipitate collected by filtration
2. washwashed with water (200 mL)
3. customdried under vacuum