It has now been found that this objective may be accomplished by carrying out the dehydration reaction in the presence of a small amount of a
1,2-dicarboxylic acid or the corresponding anhydride which acts to catalyze the dehydration of the monocarboxylic acids.
Monocarboxylic acids that may be dehydrated by the process of the invention include saturated and unsaturated aliphatic, alicyclic, aromatic and
heterocyclic acids having from about 2 to 18 carbons, as well as derivatives of these acids. Examples are acetic, propionic,
caprylic, lauric, stearic, crotonic, oleic, linoleic, cyclopropanecarboxylic, cyclohexanecarboxylic, cyclohexenecarboxylic, cyclodecanecarboxylic,
benzoic, toluic, phenylacetic, cinnamic, 1-naphthylacetic, nicotinic and benzofuroic acids.
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