Scale‑up of acetyl chloride synthesis by bubbling HCl gas through a mixture of acetic acid and acetonitrile, with precautions.
- HCl gas generator built from a 1 L flask, drying apparatus (calcium chloride), and airtight connections; gas directed into a chilled 500 mL reaction flask with stirring and cooling; moisture removed with CaCl2 drying tube.
- Reagents: 200 g anhydrous NaCl, 150 mL conc H2SO4, 50 mL glacial acetic acid, 46 mL dry acetonitrile. All water-free.
- Gas generation started slowly, maintained below 5 °C, ventilation on as precaution; absorption of HCl into the acetic acid/ACN mixture observed; dryness important to avoid heat.
- After ~60 minutes total, heating with boiling water under the gas generation to finish the reaction; 24 h cooling to crystallization.
- Distillation of acetyl chloride from the reaction mixture yielded 20.5 g of product, about 30% yield relative to starting acetic acid or acetonitrile; considered viable given cheap starting materials if acetonitrile is available.
- Product testing: with water, acetyl chloride reacts rapidly but is immiscible; with sodium acetate, exothermic formation of acetic anhydride and NaCl; leftover liquid is acetic acid + acetonitrile; crystallization of acetamide hydrochloride observed (22 g) after cooling; filtration gives crystalline material; partial recycling of acetamide hydrochloride back to acetonitrile possible with 15–20% recovery.
- Notes: other methods exist but may require difficult-to-obtain chlorinating agents; references to previous videos for acyl chloride applications (e.g., Friedel-Crafts).
- Outro: thanks for watching; more updates forthcoming.
