Rhodia Operations

Zach System

Valéry Dambrin

Denis Revelant

François Metz

Stephan Verdier

Alain Burgos

Patricia Poirier

Marie Chauve

Denis Lucet

Jacques Tonnel

The invention concerns a method for preparing an oxysulphide and fluorinated derivative, said method comprising the reacting, in the presence of an organic solvent, of: i) at least one compound of formula Ea-COOR (I), in which Ea represents the fluorine atom or a group having 1 to 10 carbon atoms chosen from fluoroalkyls, perfluoroalkyls and fluoroalkenyls and R represents hydrogen, a monovalent cation or an alkyl group, and ii) a sulphur oxide, said method being such that the initial molar ratio (sulphur oxide/compound of formula (I)) is less than 0.4 and the concentration of sulphur oxide dissolved in the reaction medium is kept constant for the entire duration of the reaction to a value of between 0.2% and 3% by weight by means of continually adding said sulphur oxide to the reaction medium.

Method for preparing oxysulphide and fluorinated derivatives by sulphination

An in situ or one-pot process for the preparation of the compounds of formula (I) uses a compound of general formula (I):  and includes: a) the hydrogenation of a nitrile group of the compound of general formula (II):  in which Rto R4 are especially H or alkyl and n varies from 0 to 4, in the presence of a hydrogenation catalyst, a methylating agent and an organic acid as solvent, and at a temperature Ta below the initiation temperature of a reductive amination reaction, to give a primary amine from the nitrile group; and b) the reductive amination of the primary amine in the presence of hydrogen, at a temperature Tb above Ta, to give the dimethylated amine of general formula (I) by activation of the methylating age.

In situ or one-pot hydrogenation and reductive amination process

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Saint Genis Laval, France

Valéry Dambrin