反应详情

A 500 mL round-bottomed flask containing Pt/C (5%, 6.00 g, 1.54 mmol) and 2-bromo-3-fluoro-6-nitroaniline (600b) (20.85 g, 89 mmol) were treated with EtOH (250 mL) and stirred under an atmosphere of H2 (balloon) for 22 h. LC-MS indicated ca. 35% conversion to the desired material (M+1=204.9/206.9). Another balloon of H2 was added and it was stirred for another 16 h resulting in >90% conversion to the desired product (M+1=204.9/207.1) by LC-MS. The suspension was filtered through a plug of Celite washing with EtOH and concentrated affording crude 3-bromo-4-fluorobenzene-1,2-diamine (18 g, 88 mmol, 99% yield) as a black/purple viscous oil. 1H NMR (400 MHz, CDCl3) δ ppm 6.60 (1H, dd, J=8.5, 5.2 Hz), 6.42-6.50 (1H, m). 19F NMR (376 MHz, CDCl3) δ ppm −116.48 (1F, s). m/z (ESI, +ve ion) 204.9/206.9 (M+H)+.

1. additionAnother balloon of H2 was added
2. stirringit was stirred for another 16 h