To a reflux apparatus add 9.3 g of 4-bromo-2-nitrobenzylidene diethanoate, 65 mL of ethanol and 64.5 mL of 1M sulfuric acid, reflux for 1h and then cool the solution down. Pour the solution into 900 g of ice, filter, wash with cold water and dry the product. Recrystallize in hot ethanol.
Reflux of the mixture
Recrystallization of the crude product
A sample of the pure product