Nitric Acid → 2-Bromo-1,3-difluoro-4-nitrobenzene

Participants

Reaction Steps

A mixture of 2,6-difluorobromobenzene (125.5 g, 650 mmol) in 98% sulphuric acid (250 ml) was cooled in an ice-water bath and then treated with a 1:1 mixture of 98% sulphuric acid and fuming nitric acid (100 ml) added at such a rate that the internal temperature never exceeded 35° C. Once addition was complete the reaction was stirred at ambient temperature for 3 h then poured onto ice. This mixture was diluted with water (final volume 5 l), the resulting solid collected by filtration, washed with water, then dried under vacuum over phosphorus pentoxide, to afford 2-bromo-1,3-difluoro-4-nitrobenzene as a cream-coloured solid (145 g, 94%): δH (360 MHz, CDCl3) 7.10-7.15 (1H, m), 8.09-8.16 (1H, m).

Provenance & Evidence