Process for preparing fluorobenzene derivatives and benzoic acid hypofluorite derivatives

A process for the manufacture of a fluorinated benzene derivative, wherein the process comprises the steps of:

• a) provision of a liquid medium comprising benzoic acid derivative as starting compound;
• b) provision of a fluorination gas comprising elemental fluorine wherein the fluorine is present in the fluorination gas in a concentration equal to or more than 20% by volume;
• c) provision of a first reactor or reactor system, resistant to elemental fluorine and hydrogen fluoride;
• d) in a step of direct fluorination, passing the fluorination gas of b), in a reactor or reactor system of c), through the liquid medium of a) comprising the benzoic acid derivative as starting compound, and thereby reacting the benzoic acid derivative starting compound with the elemental fluorine of the fluorination gas a) to substitute in the hydrogen atom in the benzoic acid derivative carboxlylic group for fluorine, and wherein the reaction is carried out at temperature of from about −30° C. to about +100° C. and a pressure of from about 1 bar absolute to about 10 bar absolute bar;
• e) withdrawing the benzoic acid hypofluorite derivative formed in the direct fluorination step d) from the reactor or reactor system of c);
• f) obtaining the benzoic acid hypofluorite derivative, in situ or in isolated form;
• and
• g) subjecting the benzoic acid hypofluorite derivative obtained in step f), in situ or in isolated form, in a second reactor or reactor system to decarboxylation, to thereby obtain the fluorinated benzene derivative;
• with the proviso that the starting compound is not benzoic acid, and the fluorinated compound produced is not benzoic acid hypofluorite, and/or subsequently after decarboxylation the product is not fluorinated benzene.