Chapter 40 Esterification. Synthesis of n-Butyl Acetate by Azeotropic Distillation of Water

Purpose In this experiment acetic acid is esterified with butanol in the presence of an acid catalyst in an azeotropic distillation mode. The product is isolated simply by withdrawing it from reaction flask with a Pasteur pipette, leaving the catalyst behind .

Reaction Mechanism The mechanism involves initial protonation of CO2H group, attack of the nucleophilic OH, a proton transfer, and loss of H2O followed by loss of the catalyzing proton to give ester.

(Moles Product / Moles Starting Material) x 100 = % Yield Comments Follow pp. 559-560 (microscale). Follow the lab handout for all experimental procedures. Note ‘fruity’ fragrance of the final product (use wafting, do not inhale!). Perform IR analysis of the product. Calculate yield. High to moderate yields should be achieved. (Moles Product / Moles Starting Material) x 100 = % Yield

Safety Flammable reagents are used in this experiment, keep away from open flame. Acetic acid is corrosive, avoid contact with skin and eyes. n-Butyl acetate can cause irritation of eyes, upper respiratory system and skin. Potential symptoms of overexposure are headache, drowsiness, narcosis. Do not inhale, avoid contact with skin and eyes.