Esterification of carboxylic acid derivatives

In the, aJcoholyas or ester-interchange reactimi (4), an alcohol reacts iKith nn to give a new ester. 

If a mixture of amyl nitrite and ethyl alcohol containing an acid catalyst is wanned, ethyl nitrite distills out. Friedel and Crafts heated ethyl acetate with amyl alcohol and amyl acetate with ethyl alcohol aijd observed alcoholysis in both cases. They also heated ethyl benzoate and amyl acetate together and obtained ethyl acetate and amyl benzoate, although this reaction was slow below 300°C. 

Thermodynamics of Alcoholysis. Alcoholysis may be regarded as a special case of esterification. Equilibrium expressions which are similar to those for the esterification of acids by alcohols may be written for alcoholysis reactions. 

The alcoholysis equilibrium (K) can be calculated from the respective esterification constants (Ki and K2) of methanol and ethanol with benzoic acid. If benzoic acid is heated with a mixture of methyl and ethyl alcohols, the following equilibriums occur [Eqs. (5) and (6)]  

This relationship between the. esterification constants is as true in the absence of wato and free acid as it is in their presence. Thus, if 1 mole of methanol is added to 1 mole olf ethyl benzoate, 0,53 mole of the methyl ester will be formed and a like amount of ethyl alcohol set free, 

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