Rhodia Chimie

Gilbert Guidot

Laurent Saint-Jalmes

Hubert Kempf

Christophe Rochin

Vincent Schanen

A method for dehydrogenofluorination for transforming an aromatic carbamoyl fluoride into a corresponding isocyanate, is provided. The method includes subjecting a carbamoyl fluoride to a temperature not less than 80&#xb0; C. in a solvent wherein the carbamoyl fluoride is in a dissolved or finely dispersed state in the solvent. The method is applicable to organic synthesis.

Method for dehydrogenofluorination of an aromatic carbamoyl fluoride

The invention concerns a method for using a carbamoyl fluoride as fluorinating agent. Said method consists in treating a derivative bearing a halogen-containing carbon, with a carbamoyl fluoride at a temperature not less than 70 &deg; C. and in maintaining the ratio between the sum of hydrofluoric acid (HF) and carbamoyl fluoride as well as between the sum of exchangeable halogen atoms, isocyanate functions and carbamoyl fluoride &lsqb;(HF&plus;carbamoyl fluoride)/(exchangeable halogen&plus;isocyanate&plus;carbamoyl fluoride)&rsqb; at a value not more than 1.2; then in carrying out a catalysis process with tin, antimony and/or titanium salt. The invention is applicable to synthesis of fluorinated derivatives.

Method for using a carbamoyl fluoride as fluorinating agent

The invention concerns a method for the synthesis of chlorinated aniline on the ring and comprising at least a sp3 hybridization carbon atom both perhalogenated and bearing a fluorine atom. Said method is characterized in that it comprises a step which consists in chlorinating a precursor aniline of said chlorinated aniline, said chlorination being carried out in a hydrofluoric medium capable of exchanging chlorine and fluorine in benzyl position. The invention is useful for the synthesis of organofluorinated and/or chlorinated compounds.

Chlorination of an aniline in a hydrofluoric medium

The present invention relates to a process for the treatment of an aryl carbamoyl fluoride comprising in its molecule at least one perhalogenated aliphatic carbon, which carbon carries at least one halogen atom to be exchanged with fluorine. This process comprises the stage of bringing the said carbamoyl fluoride into contact with hydrofluoric acid, the ratio of hydrofluoric &lsqb;lacuna&rsqb; to carbamoyl fluoride being maintained during the reaction at a value at least equal to 4, preferably to 5, and characterized in that the said ratio is at most equal to 11. Application to organic synthesis.

Growing community of inventors

Massanes, France

Gilbert Guidot