Abstract: This process for the manufacture of isobutyric anhydride by reacting acetic anhydride with isobutyric acid, distilling the acetic acid generated as it is formed, is characterized in that the reactor is initially loaded with at least a portion of one of the reagents and a portion of the other such that the reagents are in an excess molar ratio relative to the stoichiometry of one of the reagents, and the reaction is carried out while adding the remainder of the reagents as the reaction progresses and according to the place left free in the reactor by the distillation of the acetic acid produced by the reaction, until the desired overall molar ratio of the reagents is reached.

Abstract: This process for the manufacture of isobutyric anhydride by reacting acetic anhydride with isobutyric acid, distilling the acetic acid generated as it is formed, is characterized in that the reactor is initially loaded with at least a portion of one of the reagents and a portion of the other such that the reagents are in an excess molar ratio relative to the stoichiometry of one of the reagents, and the reaction is carried out while adding the remainder of the reagents as the reaction progresses and according to the place left free in the reactor by the distillation of the acetic acid produced by the reaction, until the desired overall molar ratio of the reagents is reached.

Abstract: This process for preparing an unsaturated carboxylic ester by esterifying an unsaturated carboxylic acid with an alcohol in the presence of a cationic resin catalyst, the water of reaction being removed in the form of an azeotrope with the esterifying alcohol or with a solvent, is characterized in that the esterification reaction is conducted by passing the mixture of reactants in upflow mode through a bed (9) of the said cationic resin in a recirculation loop (2) which is combined with a stirred tank (1) in which the reactants are mixed and from which the water of reaction is removed azeotropically.

Abstract: This process for preparing an unsaturated carboxylic ester by esterifying an unsaturated carboxylic acid with an alcohol in the presence of a cationic resin catalyst, the water of reaction being removed in the form of an azeotrope with the esterifying alcohol or with a solvent, is characterized in that the esterification reaction is conducted by passing the mixture of reactants in upflow mode through a bed (9) of the said cationic resin in a recirculation loop (2) which is combined with a stirred tank (1) in which the reactants are mixed and from which the water of reaction is removed azeotropically.