Abstract: A process for producing carboxylic acid anhydrides by the carbonylation reaction of a carboxylic acid ester, derived from an alcohol and a carboxylic acid, with carbon monoxide containing a small amount of hydrogen in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, the carboxylic acid anhydride, the carboxylic acid, and at least one ionic liquid consisting of a cation and an anion where the cation of the ionic liquid has a nitrogen-containing heterocyclic structure. The ionic liquid has at least one of the following structural forms: The reaction rate of the carbonylation reaction is increased by the use of the specified ionic liquid promoters.

Abstract: A process for producing carboxylic acid anhydrides by the carbonylation reaction of a carboxylic acid ester, derived from an alcohol and a carboxylic acid, with carbon monoxide containing a small amount of hydrogen in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, the carboxylic acid anhydride, the carboxylic acid, and at least one ionic liquid consisting of a cation and an anion where the cation of the ionic liquid has a nitrogen-containing heterocyclic structure. The ionic liquid has at least one of the following structural forms: The reaction rate of the carbonylation reaction is increased by the use of the specified ionic liquid promoters.

Abstract: A process for preparing a carboxylic acid by the carbonylation of an alcohol in a reaction medium is provided. The reaction medium includes a catalyst promoter having a metal species selected form the group consisting of group IIIA-IVA metals, group IB-VIIIB metals and lanthanides, together with a hydrohalic acid to prevent catalyst precipitation and to maintain high reaction rates in case of low water content.

Abstract: The present invention relates to a process for producing carboxylic acid anhydrides, in which a carboxylic acid ester, derived from an alcohol and a carboxylic acid, and carbon monoxide containing a small amount of hydrogen are used as raw materials and subjected to a carbonylation reaction in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, at least one organic promoter, the carboxylic acid anhydride and the carboxylic acid, wherein the organic promoter is selected from at least one of the following structural forms (I), (II) and (III). According to the process of the present invention, the reaction rate of the carbonylation reaction is increased by the use of the specified organic promoters.

Abstract: The present invention relates to a process for producing carboxylic acid anhydrides, in which a carboxylic acid ester, derived from an alcohol and a carboxylic acid, and carbon monoxide containing a small amount of hydrogen are used as raw materials and subjected to a carbonylation reaction in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, at least one organic promoter, the carboxylic acid anhydride and the carboxylic acid, wherein the organic promoter is selected from at least one of the following structural forms (I), (II) and (III). According to the process of the present invention, the reaction rate of the carbonylation reaction is increased by the use of the specified organic promoters.

Abstract: A process for preparing a carboxylic acid by the carbonylation of an alcohol in a reaction medium is provided. The reaction medium includes a catalyst promoter having a metal species selected form the group consisting of group IIIA-IVA metals, group IB-VIIIB metals and lanthanides, together with a hydrohalic acid to prevent catalyst precipitation and to maintain high reaction rates in case of low water content.