1,3-Dinitrobenzene (70.0g, 0.416 mol) and bromine (36.6g, 0.229 mol, 0.55 equiv) were dissolved in 400 ml 96% H2SO4. 96% HNO3 (100 ml) was dissolved in 100 ml H2SO4 and the resulting solution added to the reaction dropwise over 1 hour. Heated to 80 °C for a further 2 hours, allowed to cool to room temp, then poured onto 2 Kg ice/water. The solids were filtered off and recrystallised from IMS (denatured ethanol) to give the product as pale yellow crystals, 82.2g (80%); mp 76-77°C; 1H NMR (CDCl3) 8.69 (d, J 1.9, 2H), 9.00 (d, J 1.9, 1H).
