Rhodia Operations

Rhodia Chimie

Aubervilliers

Bernard Besson

Olivier Buisine

François Metz

Vincent Schanen

Francois Metz

Bernard Metz

The present invention relates to a method for preparing an aqueous sulfonimide compound of the formula (Rf&#x2014;SO)(Rf&#x2014;SO)NH, wherein Rfand Rfare independently selected from the group comprising: a fluorine atom and groups having 1 to 10 carbon atoms selected from the perfluoroalkyl, fluoroalkyl, fluoroalkenyl and fluoroallyl groups, from a mixture M1 including (Rf&#x2014;SO)(Rf&#x2014;SO)NH, RfSOH and/or RfSOH, RfSONHand/or RfSONH, characterized in that said method includes an oxidation step of said mixture M1 using an oxidizing agent in order to obtain a mixture M2 including (Rf&#x2014;SO)(Rf&#x2014;SO)NH, RfSOH and/or RfSOH and RfSONHand/or RfSONH.

Method for preparing a sulfonimide compound and salts thereof

The present invention relates to a method for preparing a highly pure trifluoromethanesulphinic acid. The method of the invention for preparing a highly pure trifluoromethanesulphinic acid, starting from an aqueous mixture comprising a trifluoromethanesulphinic acid salt, a trifluoroacetic acid salt and saline impurities resulting from the method for preparing same, is characterized in that said mixture is subjected to the following operations: &#x2014;acidification such that the trifluoroacetic acid salt and the triflinic acid salt are released in an acid form, &#x2014;separation of the trifluoroacetic acid and trifluoromethanesulphinic acid by distillation enabling the trifluoroacetic acid to be recovered at the top of the distillation and the trifluoromethanesulphinic acid to be recovered at the bottom of the distillation, &#x2014;separation by distillation of the trifluoromethanesulphinic acid present in the distillation residue previously obtained.

Method for preparing trifluoromethanesulphinic acid

The present invention relates to a method for preparing a salt of trifluoromethanesulphinic acid termed 'triflinic acid'. More specifically, the invention relates to a method for preparing a highly pure triflinic acid salt. The method of the invention for preparing a highly pure triflinic acid salt, starting from an aqueous mixture comprising the latter combined with a trifluoroacetic acid salt and saline impurities resulting from the method for preparing same, is characterized in that said mixture is subjected to the following operations: &#x2014;first controlled acidification such that the trifluoroacetic acid salt is essentially released in the acid form thereof, the majority of the triflinic acid remaining in a salified form, &#x2014;optional separation of the salts originating from the acid having been used for the acidification and recovery of an aqueous phase, &#x2014;separation of the trifluoroacetic acid from the separated aqueous phase comprising the alkaline salt of triflinic acid, trifluoroacetic acid, triflinic acid and the excess strong acid, therefore resulting in an aqueous phase depleted of trifluoroacetic acid but comprising the alkaline salt of triflinic acid, &#x2014;recovery of the alkaline salt of triflinic acid from the aqueous phase.

Method for preparing a trifluoromethanesulfinic acid salt

Oxysulfide and fluorinated organic compounds, for example, perfluoroalkanesulfinic and sulfonic acids, and preferably trifluoromethanesulfinic and trifluoromethanesulfonic acids in salt form, are prepared by reacting, in the presence of an aprotic polar organic solvent: (i) a fluorocarboxylic acid having the formula Ea-CF&#x2014;COOH (I), wherein Ea is an atom or an electroattracting group at least partially forming a salt with an organic or inorganic cation; with (ii) a sulfur oxide, preferably sulfur dioxide, and further wherein the ratio of the number of moles of sulfur oxide to the number of moles of fluorocarboxylic acid is less than 1, preferably less than 0.99.

Preparation of oxysulfide and fluorinated organic compounds

Sulfonic acid anhydrides, and more particularly triflic anhydride, are prepared by reacting a sulfonic acid or a mixture of two sulfonic acids with a reactant exhibiting acid pseudohalide tautomerism and containing at least one carbon atom which is involved in the tautomerism bearing two halogen atom substituents.

Preparation of sulfonic acid anhydrides

The invention relates to a method of treating an impure organic composition of ammonium imide, one of the substituents of which imide ion is a sulfonyl carried by a perhalogenated, advantageously perfluorinated carbon, characterized in that said composition is subjected to a step of liquid-liquid extraction by means of an aqueous phase and containing, as impurity, at least one of the chemical species chosen from halides, sulfonates and sulfinates, in particular those whose sulfur is carried by a perhalogenated carbon.

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Les Echets, France

Bernard Besson