METHOD OF PREPARING ACID FLUORIDES FROM ACID CHLORIDES Russian patent published in 2004 - IPC

FIELD: organic synthesis.

SUBSTANCE: invention relates to improved method for preparing sulfuryl fluoride, sulfuryl chlorofluoride, or a carboxylic acid fluoride having general formula RC(O)F, where R represents C₁-C₇-alkyl optionally substituted with at least one chlorine atom and/or with at least one fluorine atom, in absence of a HF-binding base or solvent by reacting corresponding acid chloride with (i) ammonium hydrofluoride-hydrogen fluoride adduct or pyridine hydrofluoride, or piperidine hydrofluoride, hydrogen fluoride adduct of a secondary or tertiary aliphatic amine having general formula B(HF)_m, wherein B is above-indicated amine and 1<m<4, as fluorination agent or (ii) hydrogen fluoride as fluorination agent, the latter being used in amount at least 1 mole per 1 mole of atom chlorine to be substituted, in presence of fluorination agent as defined in (i), or (iii) fluorination composition obtained by mixing HF adduct of formula B(HF)_m, wherein B is secondary or tertiary aliphatic amine, or pyridine and 1<m<4, with trifluoroacetic acid, above-indicated reaction being optionally followed by regeneration of HF adduct and separation of HCl formed in reaction. Invention likewise relates to fluorination agent obtained by mixing HF adduct of formula B(HF)_m, wherein B is secondary or tertiary aliphatic amine and 1<m<4, with trifluoroacetic acid.

EFFECT: eliminated necessity of using additional HF-binding base.

12 cl, 19 ex