反应详情

To a solution of 12.95 g (37.3 mmol) of 3,4-dibromo-(trifluoroacetamido)benzene in 150 mL of conc. H2SO4 cooled at 8° C. was added 7.0 mL of 70% HNO3 (110 mmol) over 30 min. After the addition, the stirring was continued within 10°-12° C. for 1 h and then poured into ice-water (600 mL). The precipitate was collected by vacuum filtration, washed with H2O (6×50 mL), dried at 40° C. under 1 mmHg for 12 h, affording 13.90 g (95%) of the crude product. It was crystallized from hexanes (about 180 mL) to give 10.05 g (69%) of 3,4-dibromo-2-nitro-(trifluoroacetamido)benzene. mp. 107°-9° C. IR (KBr) 3331, 3256, 1745, 1551, 1203, 1141 cm-1. 1H NMR (DMSO-d6) 11.834 (s, 1H), 8.448 (s, 1H), 8.082 (s, 1H).

1. additionAfter the addition
2. filtrationThe precipitate was collected by vacuum filtration
3. washwashed with H2O (6×50 mL)
4. customdried at 40° C. under 1 mmHg for 12 h
5. customaffording 13.90 g (95%) of the crude product
6. customIt was crystallized from hexanes (about 180 mL)