Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C.sub.5-C.sub.6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C.sub.5-C.sub.6 aldonic acid and/or lactone(s) thereof and/or a C.sub.5-C.sub.6 aldose are described.

Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C.sub.5-C.sub.6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C.sub.5-C.sub.6 aldonic acid and/or lactone(s) thereof and/or a C.sub.5-C.sub.6 aldose are described.

An object is to prevent lowering in the yield of R—COF due to contamination by impurities and thereby to produce a high-purity product of R—COF in a stable manner. According to the present invention, provided are: a method of purifying a carboxylic acid fluoride, comprising a step of removing a hydrogen halide by bringing a carboxylic acid fluoride containing the hydrogen halide into contact with a metal fluoride; a method of producing a high-purity carboxylic acid fluoride, comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride as well as a high-purity carboxylic acid fluoride obtained therefrom; and a method of using a metal fluoride as an adsorbent for a hydrogen halide in a method of removing a hydrogen halide from a carboxylic acid fluoride containing the hydrogen halide.

An object is to prevent lowering in the yield of R—COF due to contamination by impurities and thereby to produce a high-purity product of R—COF in a stable manner. According to the present invention, provided are: a method of purifying a carboxylic acid fluoride, comprising a step of removing a hydrogen halide by bringing a carboxylic acid fluoride containing the hydrogen halide into contact with a metal fluoride; a method of producing a high-purity carboxylic acid fluoride, comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride as well as a high-purity carboxylic acid fluoride obtained therefrom; and a method of using a metal fluoride as an adsorbent for a hydrogen halide in a method of removing a hydrogen halide from a carboxylic acid fluoride containing the hydrogen halide.

An object is to prevent lowering in the yield of R—COF due to contamination by impurities and thereby to produce a high-purity product of R—COF in a stable manner. According to the present invention, provided are: a method of purifying a carboxylic acid fluoride, comprising a step of removing a hydrogen halide by bringing a carboxylic acid fluoride containing the hydrogen halide into contact with a metal fluoride; a method of producing a high-purity carboxylic acid fluoride, comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride as well as a high-purity carboxylic acid fluoride obtained therefrom; and a method of using a metal fluoride as an adsorbent for a hydrogen halide in a method of removing a hydrogen halide from a carboxylic acid fluoride containing the hydrogen halide.

The present invention concerns a process for the production of a fluorinated carboxylic halide having a reduced content of impurities, a fraction of the fluorinated carboxylic halide having a reduced content of impurities, and its use in the manufacture of agriculturally and pharmaceutically active compounds or their intermediates.

The present invention concerns a process for the production of a fluorinated carboxylic halide having a reduced content of impurities, a fraction of the fluorinated carboxylic halide having a reduced content of impurities, and its use in the manufacture of agriculturally and pharmaceutically active compounds or their intermediates.

The present invention concerns a process for the production of a fluorinated carboxylic halide having a reduced content of impurities, a fraction of the fluorinated carboxylic halide having a reduced content of impurities, and its use in the manufacture of agriculturally and pharmaceutically active compounds or their intermediates.

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.