To a 3-neck RBF add 34 g of acetanilide and 40 mL of glacial acetic acid, then heat with stirring to about 65°C to dissolve the acetanilide, then cool down to 40°C and add 50 mL of ice-cold sulfuric acid with stirring. Connect thermometer and addition funnel to the RBF. Cool down to 5°C in an ice bath, at the same time combine 20 mL of very cold nitric acid with 30 mL of very cold sulfuric acid, cool down to 0°C pour to the addition funnel. Start adding the nitration mixture slowly, the temperature must be kept below 20°C. After addition let the solution sit for 30 minutes, then pour the solution to 200 mL of ice water, stir for 5 minutes then filter. Recrystallize from water and ethanol mixture. Crude p-nitroacetamide has been prepared now.
Combine 100 mL of conc. HCl and the crude p-nitroacetamide to in a RBF, reflux gently for 25 minutes. Then pour the solution to 150 mL of water, cool down to room temperature. Then combine 100 mL of 30% ammonia, 400 mL of water and 250 g of ice, add the refluxed mixture and stir for few times, filter. Recrystallize in ethanol, precipitate the product in a freezer. Recrystallization partially removes the ortho isomer from the product.
Heating the combined reagents
Sulfonation and nitration in cold
The mixture was then cooled down
Then it was poured into the ice water solution with some stirring
Filtration of the crude product
Reflux with the hydrochloric acid
Pour the mixture to the ice ammonia water
Recrystallize in ethanol
Pure recrystallized p-nitroaniline