A process is disclosed for forming a vinyl ester from a carboxylic acid and acetylene
in the presence of a zinc carboxylate catalyst, wherein a mixture of carboxylic
acid and zinc carboxylate catalyst is formed and the water content of the mixture
is reduced to between about 0.02 wt. % and about 0.3 wt. %, prior to introduction
of the acetylene into the reactor. Optionally, water is introduced into the reactor
during the reaction to hydrate any anhydride by-product of the reaction present
in the reactor to carboxylic acid reactant. Water is added during the reaction
in an amount that is sufficient to convert the anhydride by-product to carboxylic
acid reactant, but does not raise the amount of water in the reaction mixture to
a level that will reduce the reactivity of the catalyst or reduce the rate of the
vinylation reaction.
