Abstract: A method of producing (RfCO)2O by reacting RfCOCl with MmCO3 can efficiently synthesize a fluorocarboxylic anhydride in a one-step reaction, wherein Rf is a saturated hydrocarbon group having 1 to 20 carbon atoms, which optionally has an oxygen atom, in which all or part of hydrogen atoms are substituted with a fluorine atom, or a fluorine atom and another halogen atom, M is an alkali metal or an alkali earth metal, m is 2 when M is the alkali metal, or 1 when M is the alkali earth metal.

Abstract: There is disclosed an advantageous mixed acid anhydride production method of formula (1): R1C(O)OY(O)n(R2)p  (1) wherein R1, R2 and Y denote the same as defined below, n and p denote an integer of 1 or 2, which is characterized by adding a carboxylic acid of formula (2); R1COOH  (2) wherein R1 denotes a hydrogen atom, an optionally substituted alkyl group or the like, an organic base to a solution of a carboxylic acid activating agent of formula (3); (R2)pY(O)nX  (3) wherein R2 denotes an optionally substituted aliphatic hydrocarbyl group or the like, Y denotes a carbon atom, a phosphorus atom, or a sulfur atom, and X denotes a chlorine atom or the like.

Abstract: The invention relates to an improved process for the preparation of N-carboxyanhydrides by reaction of the corresponding amino acid or one of its salts with phosgene, diphosgene and/or triphosgene in a solvent medium, characterized in that at least a portion of the reaction is carried out under a pressure of less than 1000 mbar. The N-carboxyanhydrides are thus obtained with better yields and an improved purity.

Abstract: Disclosed is a process for the preparation of trifluoromethanesulfonic acid anhydride by the steps of (1) forming a mixed anhydride comprising a trifluoromethanesulfonyl acyl residue and a carboxyl residue by contacting trifluoromethanesulfonic acid or a derivative thereof with a carboxyl compound selected from ketene, dialkyl ketenes, carboxylic acids, and derivatives of carboxylic acids and (2) subjecting the mixed anhydride to reactive distillation wherein the mixed anhydride undergoes disproportionation to produce triflic anhydride and a higher boiling carboxylic acid anhydride.

Abstract: Xylene derivatives, such as chloro-ortho-xylene, are oxidized in a solvent in the presence of at least one metal catalyst with addition of promoter after the reaction has proceeded to an intermediate stage of conversion to product mixture. The product comprises chlorophthalic acid or chlorophthalic anhydride.

Abstract: A two step process, each of the steps being novel, for the production of trifluorovinyl ethers by reaction of a siloxane with selected acyl fluorides or carboxylic anhydrides, is disclosed. Also disclosed is a novel silyl ester intermediate.

Abstract: The invention relates to a novel process for the preparation of symmetrical acid anhydrides of general formula ##STR1## which process comprises reacting a compound of formula ##STR2## with an acid anhydride of formula ##STR3## with removal by distillation of the compound of formula ##STR4## R.sub.2 and X are as defined in the description, and X is chloro or bromo.

Abstract: Excess terephthalic acid or isophthalic acid is reacted with a phosgene/DMF complex nearly to completion in one or more stages to form terephthaloyl chloride or isophthaloyl chloride; in another stage, by-product formylbenzoyl chloride is oxidized and terephthaloyl chloride or isophthaloyl chloride containing less than 100 ppm of formylbenzoyl chloride and/or dichlorotoluoylchloride is recovered.

Abstract: Solid-phase copolymers of 4-vinylpyridine or 4-vinylpyridine 1-oxide may be employed as catalysts in the formation of acid anhydrides. A water soluble polymer of 4-vinylpyridine 1-oxide may also be employed as a catalyst in the formation of acid anhydrides.

Abstract: Phenol sulphonate esters can be made in a known process by reacting an alkali metal phenol sulphonate salt with an acyl halide in a hydrocarbon solvent at elevated temperatures, but the use of anhydrous materials were strongly advocated because any residual water hydrolyses the acyl chloride in a competitive reaction. However, it becomes particularly difficult and expensive to dehydrate phenol sulphonate salts below about 2% w/w water on a commercial scale and the product obtained by reaction from such partly dehydrated salts can be comparatively impure or reduced in yield. Consequently, changes to the process such as omitting the solvent or using a different acylating agent have been proposed, but these alternatives introduce their own respective manufacturing problems such as entrainment of viscous acyl chloride and anhydride in the product or introduction of a cumbersome and hence expensive recovery process involving an extra distillation step amongst others.