A highly convenient, efficient, and selective process for preparation of esters and amides from carboxylic acids using Fe(3+)-K-10 montmorillonite clay.

In the presence of Fe(3+)-K-10 montmorillonite clay as a catalyst, aliphatic carboxylic acids selectively produced the corresponding esters in the presence of aromatic carboxylic acids by treatment with alcohols. Both the aliphatic and aromatic carboxylic acids formed the amides by reacting with the aliphatic amines, but only the aliphatic carboxylic acids yielded the anilides by treatment with aromatic amines. The catalyst is recoverable and recyclable.