Preparing p-nitroacetanilide template

CBSE / ISC class 12: acetanilide in glacial ethanoic acid and conc. H₂SO₄ in a beaker in an ice bath, nitrating mixture added dropwise with a thermometer in the mixture, then poured onto crushed ice and filtered.

What the template shows

• Nitrate acetanilide below 10 °C, then pour onto ice and filter off the product
• Keep the mixture below 10 °C; hotter gives dinitration and oxidation
• Ice bath
• Ice and water (add salt for colder)
• Acetanilide solution
• Nitrating mixture
• Cold conc. HNO₃ + conc. H₂SO₄, a drop at a time. Very corrosive: fume cupboard, goggles, gloves
• Crushed ice
• After standing 20–30 min, pour the mixture onto it with stirring: pale yellow p-nitroacetanilide precipitates. Filter at the pump, wash acid-free with cold water, recrystallise from ethanol (the ortho isomer stays dissolved). M.p. about 215 °C
• Reaction setup

Drawn with 13 shapes – every one editable in MolDraw.

Sources

• Furniss et al., Vogel's Textbook of Practical Organic Chemistry, 5th ed., Longman 1989 Textbook
• Clayden, Greeves & Warren, Organic Chemistry, 2nd ed., OUP 2012, ch. 21 Textbook