Abstract: The present invention provides a process for selectively separating HF and like acids present along with water-unstable organic acid fluorides. In particular, the invention provides a process for separating an acid from a system in which the acid and an organic acid fluoride are present, the organic acid fluoride being represented by formula (I): RCOF??(I) wherein R is a fluorine atom; a C1-20 linear, branched or cyclic alkyl or halogenated alkyl group that may contain a heteroatom; or a C6-20 aryl or halogenated aryl group that may contain a heteroatom; the process comprising using as a deacidifying agent an aromatic heterocyclic compound having a boiling point of at least 50° C. and having one or more nitrogen atoms as heteroatom.

Abstract: Process for the purification of carbonyl chlorides which have been prepared by reacting carboxylic acids with phosgene or thionyl chloride in the presence of a catalyst adduct, in which the carbonyl chlorides are treated with a hydrohalide of carboxamides of the formula (I) in which R1 is hydrogen or C1- to C3-alkyl; R2 and R3 independently of one another are C1- to C4-alkyl, or R2 and R3 together are a C4- or C5-alkylene chain, and the carbonyl chloride purified in this way is isolated by separation off from the carboxamide hydrohalide phase.

Abstract: The invention relates to a continuous process for the preparation of pivaloyl chloride and of aroyl chloride, in particular of benzoyl chloride, which consists in reacting pivalic acid with a trichloromethylated aromatic compound in the presence of a catalyst at a temperature of between 60° C. and 180° C. under reduced pressure. The products formed are continuously removed from the reaction region, the hydrogen chloride formed being treated in a washing region in which a trichloromethylated compound moves countercurrentwise.

Abstract: The present invention relates to halogenated aromatic derivatives, in particular 3-chloro-4-fluoro-benzoyl chloride having the following formula: ##STR1## The aforesaid derivative is advantageously used as base product for the preparation of fluorinated compounds employed in their turn as active principles in the pharmaceutical and agricultural fields as well as in dye industry.

Abstract: This invention relates to a process for preparing certain isomers of 2,2-dimethyl-3-(2,2-disubstitutedvinyl)cyclopropanecarboxylic acid or derivatives thereof. More specifically it relates to the epimerization of the 1S cyclopropanecarboxylic acid and its derivatives into the corresponding 1R isomers.

Abstract: Acyl chlorides of the general formula ##STR1## where R is C.sub.8 -C.sub.30 -alkyl, C.sub.8 -C.sub.30 -alkenyl or C.sub.8 -C.sub.30 -alkynyl, are prepared from a carboxylic acid of the general formula II ##STR2## where R has the abovementioned meanings, and phosgene, COCl.sub.2 (III), in the presence of a catalyst adduct of phosgene and N,N-dialkylformamide of the general formula IV ##STR3## where R.sup.1 and R.sup.2 independently of one another are each C.sub.1 -C.sub.3 -alkyl, preferably a 1:1 adduct in excess N,N-dialkylformamide, the reaction product I being obtained by phase separation, by a process in which II and III are used in essentially equimolar amounts and the phase containing the catalyst adduct is reused.

Abstract: A process for preparing 2-chloroterephthaloyl chloride which comprises reacting terephthaloyl chloride with chlorine in the presence of an anhydrous ring chlorination catalyst. When the reaction mixture contains the desired amount of the monochloro product, the mixture is cooled to room temperature and the 2-chloroterephthaloyl chloride is isolated.

Abstract: Racemic dihalovinylcyclopropane carboxylic acid halides, which are intermediates of such insecticides as permethrin, cypermethrin etc., are prepared by allowing phosphorus iodides, silicon iodides or boron iodides to react with optically active dihalovinylcyclopropane carboxylic acid halides of the formula: ##STR1## wherein X and Y stand for halogen atoms and the mark * indicates an asymmetric carbon atom.

Abstract: Diastereomers can be separated with good industrial success with the aid of extractive distillation. The separation process is characterized in that an auxiliary which changes the partial pressure of the various diastereomers to be separated to a different degree and thus allows easier separation of the diastereomers by distillation is added during the distillation. Using the present process diastereomic cis/trans-permetric acid methyl esters and mixtures of menthol and isomenthol can be separated with isolation of 99% pure product.