FR3107273A1 - Process for the preparation of iodofluoroolefin compounds - Google Patents

Abstract

The present invention relates to a process for producing an iodofluoroolefin compound comprising the steps: a) contacting a fluoroolefin of formula (I) (R1) (R2) C = CH (R3) with iodine (I2 ) in the liquid phase, to form a stream A comprising a diiodofluoroalkane compound of formula (II) (R1) (R2) C (I) -CH (I) (R3); b) dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R1) (R2) C = C (I) (R3); the substituents R1, R2 and R3 being independently of each other selected from the group consisting of H, F, a C1-C10 alkyl radical optionally substituted with at least one fluorine atom, a C3-C10 cycloalkyl radical optionally substituted with at least one fluorine atom, a C2-C10 alkenyl radical optionally substituted with at least one fluorine atom, a C3-C10 cycloalkenyl radical optionally substituted with at least one fluorine atom, and a C6-C10 aryl radical optionally substituted by at least one fluorine atom; provided that at least one of the substituents R1, R2 or R3 is F or either a radical as defined above comprising at least one fluorine atom.

Description

Process for the preparation of iodofluoroolefin compounds

The present invention relates to a process for the production of fluoroolefin compounds. In particular, the present invention relates to a process for producing an iodofluoroolefin compound.

Technological background of the invention

Given the reactivity of their iodine atom, iodo-fluorinated compounds are important synthesis intermediates for the manufacture of pharmaceutical products, phytosanitary products, extinguishing agents and products for the treatment of various substrates, in particular substrates for electronic applications.

Iodo-fluorinated compounds also find applications in the field of refrigeration or in air conditioning devices. Compositions comprising CF ₃ I and HFC-152A intended for use in refrigerant compositions, in refrigeration systems, in compositions based on blowing agents, in aerosol propellants and the like are known from WO2006/112881.

Also known from application FR2794456 is a process for the preparation of trifluoromethyl iodide or pentafluoroethyl iodide. Also known from FR2745286 is a process for the preparation of trifluoromethyl iodide.

The processes for producing iodo-fluorinated compounds can be improved both in terms of conversion and reaction selectivity, but also in terms of environmental impact by using more suitable reagents or operating conditions.

The present invention aims to solve all or part of the drawbacks observed in the methods of the prior art.

According to a first aspect, the present invention relates to a method for producing an iodofluoroolefin compound comprising the steps:

1. bringing a fluoroolefin of formula (I) (R ¹ )(R ² )C=CH(R ³ ) into contact with iodine (I ₂ ) in the liquid phase, to form a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ );
2. dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R ¹ )(R ² )C=C(I)(R ³ );

the substituents R ¹ , R ² and R ³ being independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C cycloalkyl radical ₃ -C ₁₀ optionally substituted by at least one fluorine atom, a C ₂ -C ₁₀ alkenyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine atom; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

According to a preferred embodiment, R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical , a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C ₁₀ perfluoroaryl radical; provided that R ¹ , R ² and R ³ are not simultaneously H.

According to a preferred embodiment, R ¹ , R ² and R ³ are independently selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in wherein Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each n unit, selected from the group consisting of H and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

According to a preferred embodiment, said fluoroolefin is selected from the group consisting of CHF=CH ₂ , CF ₂ =CH ₂ , CHF=CHF, CF ₂ =CHF, CH ₃ -CF=CH ₂ , CH ₃ -CH=CHF , CH ₂ F-CH=CH ₂ , CH ₃ -CF=CHF, CH ₂ F-CF=CH ₂ , CH ₃ -CH=CF ₂ , CH ₂ F-CH=CHF, CHF ₂ -CH=CH ₂ , CH ₃ -CF=CF ₂ , CH ₂ F-CF=CHF, CHF ₂ -CF=CH ₂ , CH ₂ F-CH=CF ₂ , CHF ₂ -CH=CHF, CF ₃ -CH=CH ₂ , CH ₂ F-CF=CF ₂ , CHF ₂ -CF=CHF, CF ₃ -CF=CH ₂ , CHF ₂ -CH=CF ₂ , CF ₃ -CH=CHF, CHF ₂ -CF=CF ₂ , CF ₃ -CF= CHF, CF ₃ -CH=CF ₂ ; advantageously said fluoroolefin is selected from the group consisting of CF ₂ =CH ₂ , CF ₂ =CHF, CF ₃ -CH=CH ₂ , CF ₃ -CF=CH ₂ , CF ₃ -CH=CHF, CF ₃ -CF=CHF ;

and in that said diiodofluoroalkane compound is selected from the group consisting of CHFI-CH ₂ I, CF ₂ I-CH ₂ I, CHFI-CHFI, CF ₂ I-CHFI, CH ₃ -CFI-CH ₂ I, CH ₃ - CHI-CHFI, CH ₂ F-CHI-CH ₂ I, CH ₃ -CFI-CHFI, CH ₂ F-CFI-CH ₂ I, CH ₃ -CHI-CF ₂ I, CH ₂ F-CHI-CHFI, CHF ₂ -CHI-CH ₂ I, CH ₃ -CFI-CF ₂ I, CH ₂ F-CFI-CHFI, CHF ₂ -CFI-CH ₂ I, CH ₂ F-CHI-CF ₂ I, CHF ₂ -CHI-CHFI, CF ₃ -CHI-CH ₂ I, CH ₂ F-CFI-CF ₂ I, CHF ₂ -CFI-CHFI, CF ₃ -CFI-CH ₂ I, CHF ₂ -CHI-CF ₂ I, CF ₃ -CHI-CHFI , CHF ₂ -CFI-CF ₂ I, CF ₃ -CFI-CHFI, CF ₃ -CHI-CF ₂ I; advantageously said diiodofluoroalkane compound is selected from the group consisting of CF ₂ I-CH ₂ I, CF ₂ I-CHFI, CF ₃ -CHI-CH ₂ I, CF ₃ -CFI-CH ₂ I, CF ₃ -CHI-CHFI, CF ₃ -CFI-CHFI;

and in that said iodofluoroolefin is selected from the group consisting of CFI=CH ₂ , CHF=CHI, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₂ =CF-CH ₂ I, CH ₃ -CF= CHI, CH ₂ =CH-CHFI, CH ₃ -CI=CHF, CH ₃ -CH=CFI, CHF=CH-CH ₂ I, CH ₂ F-CI=CH ₂ , CH ₂ F-CH=CHI, CH ₂ =CF-CHFI, CH ₃ -CF=CFI, CHF=CF-CH ₂ I, CH ₂ F-CF=CHI, CH ₂ =CH-CF ₂ I, CH ₃ -CI=CF ₂ , CHF=CH-CHFI , CH ₂ F-CI=CHF, CH ₂ F-CH=CFI, CF ₂ =CH-CH ₂ I, CHF ₂ -CI=CH ₂ , CHF ₂ -CH=CHI, CH ₂ =CF-CF ₂ I, CHF=CF-CHFI, CH ₂ F-CF=CFI, CF ₂ =CF-CH ₂ I, CHF ₂ -CF=CHI, CHF=CH-CF ₂ I, CH ₂ F-CI=CF ₂ , CF ₂ = CH-CHFI, CHF ₂ -CI=CHF, CHF ₂ -CH=CFI, CF ₃ -CI=CH ₂ , CF ₃ -CH=CHI, CHF=CF-CF ₂ I, CF ₂ =CF-CHFI, CHF ₂ -CF=CFI, CF ₃ -CF=CHI, CF ₂ =CH-CF ₂ I, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₃ -CH=CFI, CF ₂ =CF-CF ₂ I, CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; preferably said iodofluoroolefin is selected from the group consisting of CHI=CHF, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₃ -CF=CHI, CH ₃ -CI=CHF, CH ₂ F-CI=CH ₂ , CH ₂ =CF-CHFI, CH ₂ F-CF=CHI, CH ₃ -CI=CF ₂ , CH ₂ F-CI=CHF, CHF ₂ -CI=CH ₂ , CH ₂ =CF-CF ₂ I, CHF=CF-CHFI, CHF ₂ -CF=CHI, CH ₂ F-CI=CF ₂ , CHF ₂ -CI=CHF, CF ₃ -CI=CH ₂ , CHF=CF-CF ₂ I, CHF ₂ -CF= CFI, CF ₃ -CF=CHI, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₂ =CF-CF ₂ I, CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; in particular said iodofluoroolefin is selected from the group consisting of CF ₂ =CHI, CF ₂ =CFI, CF ₃ -CI=CH ₂ , CF ₃ -CF=CHI, CF ₃ -CI=CHF, CF ₃ -CF=CFI.

According to a preferred embodiment, stream B also comprises HI, and the process comprises a separation step between said iodofluoroolefin and HI.

According to a preferred embodiment, said diiodofluoroalkane compound is dried and optionally purified before being implemented in step b).

According to a preferred embodiment, step a) is carried out in the liquid phase in the presence of a solvent selected from the group consisting of aqueous solutions of potassium iodide, ethers, fluorinated ethers, alcohols, fluorinated alcohols, esters, aromatic solvents, fluorinated aromatic solvents, halogenated solvents and mixtures thereof.

According to a preferred embodiment, step b) is implemented using a basic aqueous mixture, advantageously said mixture comprises a base selected from an alkaline or alkaline-earth hydroxide, preferably said mixture has a content in alkali or alkaline-earth hydroxide from 20 to 80% by weight based on the total weight of said mixture.

According to a preferred embodiment, step b) is carried out in the gas phase and said dehydroiodination catalyst is selected from the group consisting of an oxide, an oxyhalide or a halide of a metal or metalloid of columns 4 to 15 of the periodic table, preferably selected from the group consisting of an oxide, an oxyhalide or a halide of aluminium, iron, chromium.

According to a second aspect, the present invention provides a method for producing said diiodofluoroalkane compound comprising step a) of bringing into contact a fluoroolefin of formula (I) (R ¹ )(R ² )C=CH(R ³ ) with iodine (I ₂ ) in the liquid phase, to form a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ); with R ¹ , R ² and R ³ as defined above.

According to a preferred embodiment, said diiodofluoroalkane compound is selected from the group consisting of CHFI-CH ₂ I, CF ₂ I-CH ₂ I, CHFI-CHFI, CF ₂ I-CHFI, CH ₃ -CFI-CH ₂ I, CH ₃ -CHI-CHFI, CH ₂ F-CHI-CH ₂ I, CH ₃ -CFI-CHFI, CH ₂ F-CFI-CH ₂ I, CH ₃ -CHI-CF ₂ I, CH ₂ F-CHI-CHFI , CHF ₂ -CHI-CH ₂ I, CH ₃ -CFI-CF ₂ I, CH ₂ F-CFI-CHFI, CHF ₂ -CFI-CH ₂ I, CH ₂ F-CHI-CF ₂ I, CHF ₂ -CHI -CHFI, CF ₃ -CHI-CH ₂ I, CH ₂ F-CFI-CF ₂ I, CHF ₂ -CFI-CHFI, CF ₃ -CFI-CH ₂ I, CHF ₂ -CHI-CF ₂ I, CF ₃ - CHI-CHFI, CHF ₂ -CFI-CF ₂ I, CF ₃ -CFI-CHFI, CF ₃ -CHI-CF ₂ I; advantageously said iodofluoroalkane compound is selected from the group consisting of CF ₂ I-CH ₂ I, CF ₂ I-CHFI, CF ₃ -CHI-CH ₂ I, CF ₃ -CFI-CH ₂ I, CF ₃ -CHI-CHFI, CF ₃ -CFI-CHFI.

According to a preferred embodiment, said diiodofluoroalkane compound is isolated and purified.

Detailed description of the present invention

According to a first aspect, the present invention relates to a process for the production of an iodofluoroolefin compound. Preferably, said method comprises at least one step of bringing a fluoroolefin of formula (I) (R ¹ )(R ² )C=CH(R ³ ) into contact with iodine (I ₂ ) in the liquid phase , to form a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ). Preferably, said process also comprises a step of dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R ¹ )(R ² )C=C (I)(R ³ ). The substituents R ¹ , R ² and R ³ being as defined below.

Thus, said method comprises the steps:

1. bringing a fluoroolefin of formula (I) (R ¹ )(R ² )C=CH(R ³ ) into contact with iodine (I ₂ ) in the liquid phase, to form a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ );
2. dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R ¹ )(R ² )C=C(I)(R ³ );

the substituents R ¹ , R ² and R ³ being independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C cycloalkyl radical ₃ -C ₁₀ optionally substituted by at least one fluorine atom, a C ₂ -C ₁₀ alkenyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine atom; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

Step a) of the process

Step a) of the present process requires contact between a fluoroolefin and iodine (I ₂ ) in the liquid phase.

Said fluoroolefin is preferably of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H , F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by at least one fluorine atom, a C _{2 -} alkenyl radical C ₁₀ optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine atom, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine atom ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

Said fluoroolefin is preferably of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H , F, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by at least one fluorine atom, a C ₂ -C ₁₀ alkenyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine atom, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine atom; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

The term "alkyl" designates a monovalent radical derived from an alkane, linear or branched, comprising the number of carbon atoms specified. The term "cycloalkyl" means a monovalent radical derived from a cycloalkane comprising the specified number of carbon atoms. The term "alkenyl" means a monovalent radical comprising the specified number of carbon atoms and at least one carbon-carbon double bond. The term "cycloalkenyl" refers to a monovalent radical derived from a cycloalkene comprising the number of carbon atoms specified and at least one carbon-carbon double bond in its cyclic part. The term “aryl” denotes a monovalent radical from an arene comprising the specified number of carbon atoms.

Preferably, said alkyl, cycloalkyl, alkenyl, cycloalkenyl or aryl radical is not substituted by functional groups other than fluorine. Said radical can nevertheless comprise several fluorine atoms on its carbon chain. For example, said radical can contain from 1 to 10 fluorine atoms, preferably from 1 to 5 fluorine atoms.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₂ -C alkenyl radical ₁₀ optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₂ -C ₁₀ alkenyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₂ -C alkenyl radical ₁₀ optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₂ -C ₁₀ alkenyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, I, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₁₀ perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ perfluoroaryl radical _-C10 ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₁₀ perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C perfluoroaryl radical ₁₀ ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, I, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ perfluoroaryl radical _-C10 ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C perfluoroaryl radical ₁₀ ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Alternatively, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, I , F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, I, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of in H and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said fluoroolefin is of formula (I) (R ¹ )(R ² )C=CH(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of in H and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

According to a preferred embodiment, said fluoroolefin is selected from the group consisting of CHF=CH ₂ , CF ₂ =CH ₂ , CHF=CHF, CF ₂ =CHF, CH ₃ -CF=CH ₂ , CH ₃ -CH=CHF , CH ₂ F-CH=CH ₂ , CH ₃ -CF=CHF, CH ₂ F-CF=CH ₂ , CH ₃ -CH=CF ₂ , CH ₂ F-CH=CHF, CHF ₂ -CH=CH ₂ , CH ₃ -CF=CF ₂ , CH ₂ F-CF=CHF, CHF ₂ -CF=CH ₂ , CH ₂ F-CH=CF ₂ , CHF ₂ -CH=CHF, CF ₃ -CH=CH ₂ , CH ₂ F-CF=CF ₂ , CHF ₂ -CF=CHF, CF ₃ -CF=CH ₂ , CHF ₂ -CH=CF ₂ , CF ₃ -CH=CHF, CHF ₂ -CF=CF ₂ , CF ₃ -CF= CHF, CF ₃ -CH=CF ₂ . Advantageously, said fluoroolefin is selected from the group consisting of CF ₂ =CH ₂ , CF ₂ =CHF, CF ₃ -CH=CH ₂ , CF ₃ -CF=CH ₂ , CF ₃ -CH=CHF, CF ₃ -CF= CHF.

Said fluoroolefin may have a boiling point below 100° C. at atmospheric pressure. Advantageously, said fluoroolefin has a boiling point below 75° C. at atmospheric pressure. Preferably, said fluoroolefin has a boiling point below 50° C. at atmospheric pressure. More preferably, said fluoroolefin has a boiling point below 25° C. at atmospheric pressure. In particular, said fluoroolefin has a boiling point below 10° C. at atmospheric pressure.

According to a preferred embodiment, step a) can be implemented in the presence of a mixture of fluoroolefins to lead to the coproduction of iodofluoroolefins via the corresponding diiodofluoroalkane compounds, in accordance with the present process.

Step a) allows the formation of a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by at least one fluorine, a C ₂ -C ₁₀ alkenyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine atom, and a C ₆ -C aryl radical optionally substituted with at least _one fluorine atom; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₂ -C ₁₀ alkenyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, an alkenyl radical C ₂ -C ₁₀ radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₂ -C ₁₀ alkenyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, an alkenyl radical C ₂ -C ₁₀ radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 fluorine atoms; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group _consisting of H, F, I, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C 10 perfluorocycloalkyl radical, a C ₂ -C ₁₀ perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical , a C ₆ -C ₁₀ perfluoroaryl radical; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₁₀ perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C ₁₀ perfluoroaryl radical; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group _consisting of H, F, I, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C 10 perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical , a C ₆ -C ₁₀ perfluoroaryl radical; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C ₁₀ perfluoroaryl radical; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Alternatively, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, I, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, I, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - wherein Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said diiodofluoroalkane compound is of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ ) in which R ¹ , R ² and R ³ are independently selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

In particular, said diiodofluoroalkane compound is selected from the group consisting of CHFI-CH ₂ I, CF ₂ I-CH ₂ I, CHFI-CHFI, CF ₂ I-CHFI, CH ₃ -CFI-CH ₂ I, CH ₃ -CHI -CHFI, CH ₂ F-CHI-CH ₂ I, CH ₃ -CFI-CHFI, CH ₂ F-CFI-CH ₂ I, CH ₃ -CHI-CF ₂ I, CH ₂ F-CHI-CHFI, CHF ₂ - CHI-CH ₂ I, CH ₃ -CFI-CF ₂ I, CH ₂ F-CFI-CHFI, CHF ₂ -CFI-CH ₂ I, CH ₂ F-CHI-CF ₂ I, CHF ₂ -CHI-CHFI, CF ₃ -CHI-CH ₂ I, CH ₂ F-CFI-CF ₂ I, CHF ₂ -CFI-CHFI, CF ₃ -CFI-CH ₂ I, CHF ₂ -CHI-CF ₂ I, CF ₃ -CHI-CHFI, CHF ₂ -CFI-CF ₂ I, CF ₃ -CFI-CHFI, CF ₃ -CHI-CF ₂ I. More particularly, said diiodofluoroalkane compound is selected from the group consisting of CF ₂ I-CH ₂ I, CF ₂ I- CHFI, CF ₃ -CHI-CH ₂ I, CF ₃ -CFI-CH ₂ I, CF ₃ -CHI-CHFI, CF ₃ -CFI-CHFI.

Preferably, step a) allows at least one of the following reactions:

• converting CHF=CH ₂ to CHFI-CH ₂ I; Or
• converting CF ₂ =CH ₂ to CF ₂ I-CH ₂ I; Or
• the conversion of CHF=CHF into CHFI-CHFI; Or
• converting CF ₂ =CHF to CF ₂ I-CHFI; Or
• converting CH ₃ -CF=CH ₂ to CH ₃ -CFI-CH ₂ I; Or
• converting CH ₃ -CH=CHF to CH ₃ -CHI-CHFI; Or
• converting CH ₂ F-CH=CH ₂ to CH ₂ F-CHI-CH ₂ I; Or
• converting CH ₃ -CF=CHF to CH ₃ -CFI-CHFI; Or
• converting CH ₂ F-CF=CH ₂ to CH ₂ F-CFI-CH ₂ I; Or
• converting CH ₃ -CH=CF ₂ to CH ₃ -CHI-CF ₂ I; Or
• converting CH ₂ F-CH=CHF to CH ₂ F-CHI-CHFI; Or
• converting CHF ₂ -CH=CH ₂ to CHF ₂ -CHI-CH ₂ I; Or
• converting CH ₃ -CF=CF ₂ to CH ₃ -CFI-CF ₂ I; Or
• converting CH ₂ F-CF=CHF to CH ₂ F-CFI-CHFI; Or
• converting CHF ₂ -CF=CH ₂ to CHF ₂ -CFI-CH ₂ I; Or
• converting CH ₂ F-CH=CF ₂ to CH ₂ F-CHI-CF ₂ I; Or
• converting CHF ₂ -CH=CHF to CHF ₂ -CHI-CHFI; Or
• converting CF ₃ -CH=CH ₂ to CF ₃ -CHI-CH ₂ I; Or
• converting CH ₂ F-CF=CF ₂ to CH ₂ F-CFI-CF ₂ I; Or
• the conversion of CHF ₂ -CF=CHF into CHF ₂ -CFI-CHFI; Or
• converting CF ₃ -CF=CH ₂ to CF ₃ -CFI-CH ₂ I; Or
• converting CHF ₂ -CH=CF ₂ to CHF ₂ -CHI-CF ₂ I; Or
• converting CF ₃ -CH=CHF to CF ₃ -CHI-CHFI;
• converting CHF ₂ -CF=CF ₂ to CHF ₂ -CFI-CF ₂ I; Or
• converting CF ₃ -CF=CHF to CF ₃ -CFI-CHFI; Or
• the conversion of CF ₃ -CH=CF ₂ into CF ₃ -CHI-CF ₂ I.

Preferably, step a) is implemented in the absence of catalyst. Preferably, step a) is implemented in the presence of a solvent S1 . Preferably, the solvent S1 is selected from the group consisting of aqueous solutions of potassium iodide, ethers, fluorinated ethers, alcohols, fluorinated alcohols, esters, aromatic solvents, fluorinated aromatic solvents, halogens and mixtures thereof. Advantageously, the solvent S1 is selected from the group consisting of aqueous solutions of potassium iodide, ethyl and methyl ethers, hydrofluoroethers, ethyl and methyl alcohols, ethyl lactate, toluene, xylenes, parachlorotrifluoromethylbenzene , hexafluorobenzene, tetrachloromethane, chloroform, dichloromethane, 1-bromopropane and mixtures thereof. The use of a solvent in the present process makes it possible to avoid clogging problems linked to the sublimation of iodine and also to limit the formation of impurities (by-products of reactions, polymers resulting from the fluoroolefin, etc.) , which makes it possible to achieve selectivities which are particularly advantageous at the industrial level.

Preferably, the iodine is brought into contact with said fluoroolefin as defined above at stoichiometry or in excess with respect thereto. For example, the I ₂ /olefin molar ratio is from 0.1 to 50, preferably from 0.5 to 25, in particular from 1 to 20.

Preferably, the dissolved oxygen content in the solvent S1 is less than 3000 ppm, advantageously less than 2000 ppm, preferably less than 1000 ppm, more preferably less than 500 ppm, in particular less than 250 ppm, more particularly less than 100 ppm, preferably less than 50 ppm, preferably preferably less than 10 ppm. This makes it possible to avoid the degradation of the starting materials and the desired products. Solvent S1 preferably has a boiling point of 0°C to 250°C, preferably 20°C to 250°C, in particular 20°C to 200°C.

The implementation temperature of step a) is from 20°C to 280°C, preferably from 30°C to 250°C. Step a) can be implemented at a pressure of 0.1 bar to 15 bar, preferably 1 bara to 10 bara.

Said diiodofluoroalkane compound can be dried before being implemented in step b). This removes any traces of water that may be present. The drying can be carried out by bringing it into contact with an adsorbent, an absorbent, a sieve of 3 to 5 Angstoms or zeolites.

Said diiodofluoroalkane compound can be purified before being used in step b). The purification can be implemented before or after the drying step. This makes it possible to eliminate certain impurities that are potentially difficult to separate from the iodofluoroolefin compound obtained in step b). This step can also make it possible to increase the selectivity of step b). Purification can be carried out by distillation, azeotropic distillation, pressure distillation, extractive distillation, cold separation, absorption in a solvent, or by contacting with an adsorbent or a combination thereof. Advantageously, the purification of the diiodofluoroalkane compound aims to result in a stream A in which the content of diiodofluoroalkane compound is greater than 90%, advantageously greater than 92%, preferably greater than 94%, more preferably greater than 96%, in particular greater than to 98%, more particularly greater than 99%. This flow A is then implemented in step b).

When step a) is implemented from a mixture of fluoroolefins, the purification, if it is implemented, makes it possible to obtain a mixture of diiodofluoroalkane compounds or a particular diiodofluoroalkane compound depending on the conditions used to put carry out purification.

Said dried diiodofluoroalkane compound can be purified as described above or used as such in step b). Said dried diiodofluoroalkane compound is used directly in step b) without being purified after the drying step, for example when step a) is carried out with high conversion and selectivity, for example greater than 90%, preferably greater than 95%. The absence of purification between step a) and step b) can be advantageous from the point of view of the overall productivity of the process; a purification step that can generate significant costs.

The diiodofluoroalkane compound used in step b) is preferably anhydrous, i.e. the stream containing the diiodofluoroalkane compound used in step b) is anhydrous. The term anhydrous here refers to a mass content of water in the stream containing said diiodofluoroalkane compound and used in step b) of less than 500 ppm of water, advantageously less than 250 ppm, preferably less than 100 ppm of water , more preferably less than 50 ppm of water, in particular less than 25 ppm of water, more particularly less than 10 ppm, more preferably less than 5 ppm of water, more preferably said diiodofluoroalkane compound or the stream in which it is contained for the implementation of step b) is devoid of water.

Step b) of the process

Step b) of the present process is a step of dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R ¹ )(R ² )C =C(I)(R ³ ).

Said iodofluoroolefin obtained in step b) is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by at least one fluorine atom, a C ₂ -C ₁₀ alkenyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine atom, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine atom; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

Said iodofluoroolefin is preferably of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by at least one fluorine atom, a C ₂ alkenyl radical -C ₁₀ optionally substituted by at least one fluorine atom, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by at least one fluorine atom, and a C ₆ -C ₁₀ aryl radical optionally substituted by at least one fluorine; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above comprising at least one fluorine atom.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, a C alkenyl radical ₂ -C ₁₀ optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 atoms fluorine; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 10 fluorine atoms, a C ₂ - alkenyl radical C ₁₀ optionally substituted by 1 to 10 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 10 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 10 fluorine atoms ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 10 fluorine atoms.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, I, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, a C alkenyl radical ₂ -C ₁₀ optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 atoms fluorine; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, a C ₁ -C ₁₀ alkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkyl radical optionally substituted by 1 to 5 fluorine atoms, a C ₂ - alkenyl radical C ₁₀ optionally substituted by 1 to 5 fluorine atoms, a C ₃ -C ₁₀ cycloalkenyl radical optionally substituted by 1 to 5 fluorine atoms, and a C ₆ -C ₁₀ aryl radical optionally substituted by 1 to 5 fluorine atoms ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a radical as defined above containing from 1 to 5 fluorine atoms.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, I, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C 10 perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical, _a perfluoroaryl radical C ₆ -C ₁₀ ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, a C ₁ -C ₁₀ perfluoroalkyl radical, a C ₃ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₁₀ perfluoroalkenyl radical, a C ₃ -C ₁₀ perfluorocycloalkenyl radical, a C 3 -C 10 perfluoroaryl radical ₆ - _C10 ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, I, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a perfluoroaryl radical C ₆ -C ₁₀ ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ -C ₁₀ perfluorocycloalkyl radical, a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C 5 -C 10 perfluoroaryl radical ₆ - _C10 ; provided that at least one of the substituents R ¹ , R ² or R ³ is F or is a perfluorinated radical as defined above.

Alternatively, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of H, I, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, I, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H, I and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

Preferably, said iodofluoroolefin is of formula (III) (R ¹ )(R ² )C=C(I)(R ³ ) in which R ¹ , R ² and R ³ are independently of each other selected from the group consisting of in H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H and F; and n is an integer from 1 to 5; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F.

In particular, said iodofluoroolefin is selected from the group consisting of CFI=CH ₂ , CHF=CHI, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₂ =CF-CH ₂ I, CH ₃ -CF=CHI , CH ₂ =CH-CHFI, CH ₃ -CI=CHF, CH ₃ -CH=CFI, CHF=CH-CH ₂ I, CH ₂ F-CI=CH ₂ , CH ₂ F-CH=CHI, CH ₂ = CF-CHFI, CH ₃ -CF=CFI, CHF=CF-CH ₂ I, CH ₂ F-CF=CHI, CH ₂ =CH-CF ₂ I, CH ₃ -CI=CF ₂ , CHF=CH-CHFI, CH ₂ F-CI=CHF, CH ₂ F-CH=CFI, CF ₂ =CH-CH ₂ I, CHF ₂ -CI=CH ₂ , CHF ₂ -CH=CHI, CH ₂ =CF-CF ₂ I, CHF =CF-CHFI, CH ₂ F-CF=CFI, CF ₂ =CF-CH ₂ I, CHF ₂ -CF=CHI, CHF=CH-CF ₂ I, CH ₂ F-CI=CF ₂ , CF ₂ =CH -CHFI, CHF ₂ -CI=CHF, CHF ₂ -CH=CFI, CF ₃ -CI=CH ₂ , CF ₃ -CH=CHI, CHF=CF-CF ₂ I, CF ₂ =CF-CHFI, CHF ₂ - CF=CFI, CF ₃ -CF=CHI, CF ₂ =CH-CF ₂ I, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₃ -CH=CFI, CF ₂ =CF-CF ₂ I , CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; preferably said iodofluoroolefin is selected from the group consisting of CHI=CHF, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₃ -CF=CHI, CH ₃ -CI=CHF, CH ₂ F-CI=CH ₂ , CH ₂ =CF-CHFI, CH ₂ F-CF=CHI, CH ₃ -CI=CF ₂ , CH ₂ F-CI=CHF, CHF ₂ -CI=CH ₂ , CH ₂ =CF-CF ₂ I, CHF=CF-CHFI, CHF ₂ -CF=CHI, CH ₂ F-CI=CF ₂ , CHF ₂ -CI=CHF, CF ₃ -CI=CH ₂ , CHF=CF-CF ₂ I, CHF ₂ -CF= CFI, CF ₃ -CF=CHI, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₂ =CF-CF ₂ I, CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; in particular said iodofluoroolefin is selected from the group consisting of CF ₂ =CHI, CF ₂ =CFI, CF ₃ -CI=CH ₂ , CF ₃ -CF=CHI, CF ₃ -CI=CHF, CF ₃ -CF=CFI.

Preferably, step b) allows at least one of the following reactions:

• converting CHFI-CH ₂ I to CHI=CHF;
• converting CF ₂ I-CH ₂ I to CF ₂ =CHI;
• converting CHFI-CHFI to CFI=CHF;
• converting CF ₂ I-CHFI to CF ₂ =CFI;
• converting CH ₃ -CFI-CH ₂ I to CH ₃ -CF=CHI;
• converting CH ₃ -CHI-CHFI to CH ₃ -CI=CHF;
• the conversion of CH ₂ F-CHI-CH ₂ I to CH ₂ F-CI=CH ₂ ;
• converting CH ₃ -CFI-CHFI to CH ₂ =CF-CHFI;
• converting CH ₂ F-CFI-CH ₂ I to CH ₂ F-CF=CHI;
• the conversion of CH ₃ -CHI-CF ₂ I to CH ₃ -CI=CF ₂ ;
• converting CH ₂ F-CHI-CHFI to CH ₂ F-CI=CHF;
• the conversion of CHF ₂ -CHI-CH ₂ I into CHF ₂ -CI=CH ₂ ;
• converting CH ₃ -CFI-CF ₂ I to CH ₂ =CF-CF ₂ I;
• the conversion of CH ₂ F-CFI-CHFI into CHF=CF-CHFI;
• converting CHF ₂ -CFI-CH ₂ I to CHF ₂ -CF=CHI;
• the conversion of CH ₂ F-CHI-CF ₂ I to CH ₂ F-CI=CF ₂ ;
• the conversion of CHF ₂ -CHI-CHFI into CHF ₂ -CI=CHF;
• the conversion of CF ₃ -CHI-CH ₂ I to CF ₃ -CI=CH ₂ ;
• converting CH ₂ F-CFI-CF ₂ I to CHF=CF-CF ₂ I;
• the conversion of CHF ₂ -CFI-CHFI into CHF ₂ -CF=CFI;
• converting CF ₃ -CFI-CH ₂ I to CF ₃ -CF=CHI;
• the conversion of CHF ₂ -CHI-CF ₂ I into CHF ₂ -CI=CF ₂ ;
• the conversion of CF ₃ -CHI-CHFI to CF ₃ -CI=CHF;
• converting CHF ₂ -CFI-CF ₂ I to CF ₂ =CF-CF ₂ I;
• converting CF ₃ -CFI-CHFI to CF ₃ -CF=CFI;
• the conversion of CF ₃ -CHI-CF ₂ I into CF ₃ -CI=CF ₂ .

Step b) in the gas phase

Step b) can be carried out in the gas phase.

Step b) can be implemented in the gas phase and in the presence of a catalyst or not.

Preferably, the dehydroiodination catalyst is selected from the group consisting of an oxide, an oxyhalide or a halide of a metal or metalloid from columns 4 to 15 of the periodic table or of a metal selected from Li, Na, K, Cs , Mg, Ca, Al and Sb.

In particular, the dehydroiodination catalyst is selected from the group consisting of an oxide, an oxyhalide or an aluminum, iron or chromium halide. Preferably, the catalyst is a chromium oxide, chromium oxyfluoride or a chromium fluoride. The chromium oxyfluoride preferably contains a fluorine content of 10% to 50% by weight, preferably 20% to 50% by weight, in particular 30% to 50% by weight. The fluorine content is measured by ionometry or by change in the weight of the catalyst or by any other quantitative method known to those skilled in the art. The chromium oxyfluoride or chromium fluoride catalyst preferably has a specific surface of 15 to 100 m²/g. The chromium oxide catalyst preferably has a specific surface of 100 to 300m²/g. The specific surface is measured on a Micromeritics Gemini 2360 device using the standard 5-point method (BET method). When the catalyst is a chromium oxide, chromium oxyfluoride or a chromium fluoride; this may also contain from 0.5 to 10% by weight of a co-catalyst based on the total weight of the catalyst. Said co-catalyst is chosen from Cr, Ni, Zn, Ti, V, Zr, Mo, Ge, Sn, Pb, Mg.

When the catalyst is selected from the group consisting of an oxide, an oxyhalide or a halide of a metal or a metalloid from columns 4 to 15 of the periodic table, it can be activated before its use in step b ). For example, said catalyst can be activated in the presence of oxygen, air, hydrogen iodide or HF or a mixture thereof. The catalyst can also be regenerated after the implementation of the present process. The regeneration step may include bringing the catalyst into contact with a stream of oxygen or air at a temperature of 200°C to 700°C. The catalyst can also deactivate over time. Thus, step b) can be implemented in the presence of oxygen or air or an oxygen-nitrogen mixture. If oxygen is used in step b), this is present in a content of 0.005% to 10% mol with respect to the amount in moles of fluoroolefin.

When the metal is selected from Li, Na, K, Cs, Mg, Ca, Al and Sb, the anion associated with the metal is F ^- , Cl ^- , I ^- or CO ₃ ^2- . Preferably, the catalyst is NaI, KI, SbF ₅ , AlF ₃ or SbCl ₅ . The catalyst preferably has a specific surface of between 20 and 1000m²/g, in particular between 20 and 300m²/g. When the catalyst metal is selected from Li, Na, K, Cs, Mg, Ca, Al and Sb, the catalyst content is 1 to 30% by weight with respect to said fluoroolefin.

The catalyst can be deposited on a porous support. The porous support can be chosen from activated carbons, graphite, aluminas and alumina fluorides.

According to a preferred embodiment, in the gas phase, in the presence or absence of a catalyst, step b) is implemented at a pressure of 1 bar absolute to 20 bars absolute, preferably from 3 to 15 bars absolute.

According to a preferred embodiment, in the gas phase, in the presence or not of a catalyst, step b) is carried out at a temperature of 150° C. to 700° C., preferably of 250° C. to 600° C. vs.

According to a preferred embodiment, stream B also includes HI. Said method thus comprises a separation step between said iodofluoroolefin and HI.

Step b) in non-aqueous liquid phase

Step b) can be implemented in the non-aqueous liquid phase in the presence or absence of a catalyst. Preferably, when step b) is implemented in the non-aqueous liquid phase and in the presence of a solvent S 2 . Preferably, the solvent S 2 is anhydrous. The term anhydrous here refers to a solvent S 2 containing less than 500 ppm of water, advantageously less than 250 ppm, preferably less than 100 ppm of water, more preferably less than 50 ppm of water, in particular less than 25 ppm of water, more particularly less than 10 ppm, preferably less than 5 ppm of water, preferably preferably said solvent S 2 is devoid of water. The solvent S 2 having a boiling point of 0°C to 250°C, preferably of 20°C to 250°C, in particular of 20°C to 200°C. Said solvent S 2 is selected from the group consisting of acetic acid, CCl ₄ , chloroform, dichloromethane, sulfolane, tetramethylene sulfone, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl- 2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone and mixtures thereof.

Preferably, step b), in the non-aqueous liquid phase, is carried out in the presence of a catalyst selected from alkali metal or alkaline-earth salts. Preferably, the catalyst is an alkaline salt. The iodide of any alkali metal can be used, but it is preferred to use sodium iodide or potassium iodide. The ratio between the catalyst and said fluoroolefin is between 1 and 20, preferably between 1 and 10. The catalyst preferably has a specific surface area between 20 and 1000m²/g, in particular between 20 and 300m²/g. The catalyst can be deposited on a porous support. The porous support can be chosen from activated carbons, graphite, aluminas, alumina fluorides.

The temperature for implementing step b) in the non-aqueous liquid phase is from 50°C to 280°C, preferably from 50°C to 250°C.

According to a preferred embodiment, stream B also includes HI. Said method thus comprises a separation step between said iodofluoroolefin and HI.

Step b) in aqueous phase

Step b) can be implemented using a basic aqueous mixture. The basic aqueous mixture is a liquid (for example a solution, a dispersion, an emulsion or a suspension) having a pH of at least 7, advantageously at least 8, preferably at least 10. A pH of at least 10 promotes the dehydroiodination reaction. The basic aqueous mixture comprises a base selected from the group consisting of hydroxide, oxide, carbonate or phosphate salts of alkali or alkaline earth metals. Preferably, the base is selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, potassium carbonate, sodium phosphate, potassium phosphate or a mixture thereof. In particular, the base is selected from the group consisting of alkali or alkaline earth hydroxides and a mixture thereof. More particularly, the base is selected from the group consisting of sodium hydroxide, potassium hydroxide or calcium hydroxide and a mixture thereof.

Advantageously, said basic aqueous mixture has a content of said base of 20 to 80% by weight based on the total weight of said mixture, preferably a content of 30 to 75% by weight based on said mixture, whatever the base.

In this embodiment, step b) is carried out at a temperature of 25°C to 250°C, advantageously from 25°C to 150°C, preferably from 25°C to 100°C.

In this particular embodiment, step b) can be implemented in the presence of a non-aqueous and non-alcoholic solvent, in addition to said basic aqueous mixture. A phase transfer catalyst can also be used. Said non-aqueous and non-alcoholic solvent is selected from the group consisting of acetonitrile, propionitrile, butyronitrile, methyl glutaronitrile, adiponitrile, benzonitrile, ethylene carbonate, propylene carbonate, methyl ethyl ketone, methyl isoamyl ketone, diisobutyl ketone, anisole, 2-methyltetrahydrofuran , tetrahydrofuran, dioxane, diglyme, triglyme, tetraglyme, N,N-dimethyl formamide, N,N-dimethyl acetamide, N-methyl pyrrolidinone, sulfolane, dimethyl sulfoxide, perfluoro-N-methyl morpholine, perfluorotetrahydrofuran, and mixtures thereof this. Preferably, said non-aqueous and non-alcoholic solvent is selected from acetonitrile, adiponitrile, 2-methyl tetrahydrofuran, tetrahydrofuran, dioxane, diglyme, and tetraglyme.

Phase transfer catalyst is a substance that facilitates the transfer of ionic compounds from an aqueous phase to an organic phase. The phase transfer catalyst is preferably selected from the group consisting of crown ethers, onium salts, cryptands, polyalkylene glycol ethers and mixtures thereof. The amount of phase transfer catalyst is 0.001 to 10 mole% based on the amount of base in the liquid phase, preferably 0.01 to 5 mole% based on the amount of base in the liquid phase, preferably from 0.05 to 5 mole% based on the amount of base in the liquid phase.

Crown ethers are cyclic molecules in which the ether groups are linked by a dimethylene group; the compounds form a molecular structure capable of trapping an alkali metal ion. Crown ethers include 18-crown-6 used in combination with a basic aqueous mixture containing KOH, 15-crown-5 used in combination with a basic aqueous mixture containing NaOH, 12-crown-4 used in combination with a basic aqueous mixture containing LiOH. Onium salts include quaternary phosphonium salts and quaternary ammonium salts of formula R^ToR^bR^vsR^dP^{( +)}X^-or R^ToR^bR^vsR^dNOT⁽⁺⁾X^-in which R^To, R^b, R^vsand R^dare independently selected from a group C₁-VS_{4 0}alkyl, C₆-VS_{4 0}aryl or C₆-VS_{4 0}aralkyl and X is selected from the group consisting of F, Cl, Br, I, OH, CO₃, HCO₃, SO₄, HSO₄, H₂PO₄, HPO₄and PO₄. For example, onium salts include tetramethylammonium chloride, tetramethylammonium bromide, benzyltriethylammonium chloride, methyltrioctylammonium chloride, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium chloride, triphenylmethylphosphonium bromide and triphenylmethylphosphonium chloride. Polyalkylene glycol ethers include compounds of formula R^fGOLD^eO)_youR^gin which R^eis an alkylene group containing two or more carbon atoms and each R^f and R^gare independently H, an alkyl, an aryl or an aralkyl group and t is an integer greater than 2. Ethers of polyalkylene glycols include, for example, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, diisopropylene glycol, dipropylene glycol , dipropylene glycol, tripropylene glycol, tetrapropylene glycol, tetramethylene glycol, and monoalkyl ethers thereof, dialkyl ethers thereof, and polyalkylene glycols such as polyethylene glycol dimethyl ether, polyethylene glycol dibutyl ether. Among the cryptands, mention may be made of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo-(8.8.8)hexacosane (Cryptand™ 222 and Kryptofix™ 222).

According to a preferred embodiment, depending on the base used, an iodide salt is formed. This can be KI, CaI ₂ or NaI for example.

According to a preferred embodiment, step b) is implemented at a pressure of 1 bar absolute to 20 bars absolute, preferably from 3 to 15 bars absolute.

Stage vs ) of the process

Preferably, the present process comprises a step c) of purifying the stream B obtained in step b) to form a stream B1 comprising said iodofluoroolefin and a stream B2 comprising impurities, by-products or starting products not not reacting. Preferably, after the purification step, the content of said iodofluoroolefin in said stream B 1 is greater than 90%, advantageously greater than 92%, preferably greater than 94%, more preferably greater than 96%, in particular greater than 98%, more particularly greater than 99%. Said stream B is preferably purified by distillation, azeotropic distillation, pressure distillation, extractive distillation, cold separation, absorption in a solvent or a combination thereof. Said stream B can also be separated or purified by bringing it into contact with an adsorbent. Said adsorbent may be a zeolite or a molecular sieve having a pore opening with an average diameter of between 3 Angström and 11 Angström, advantageously between 4 Angström and 10 Angström, preferably between 5 Angström and 10 Angström.

The present method can be implemented continuously or discontinuously or semi-discontinuously. Steps a) and b) can be implemented or implemented in two different reactors or in a single reactor. When several reactors are used, these are arranged in series.

Preferably, in order to avoid corrosion problems, the reactor(s) in which steps a) and b) are implemented, are made of a material comprising a layer base made of an M1 material and an inner layer made of an M2 material.

Advantageously, the material M2 comprises at least 40% by weight of nickel based on the total weight of the material M2 . Preferably, the material M2 comprises at least 45% by weight of nickel, more preferably at least 50% by weight of nickel, in particular at least 55% by weight of nickel, more particularly at least 60% by weight of nickel, of preferably at least 65% by weight of nickel, more preferably at least 70% by weight of nickel based on the total weight of the material M2 .

The material M2 may also comprise chromium in a content of less than 35% by weight based on the total weight of the material M2 , advantageously less than 30% by weight, preferably less than 20% by weight, more preferably less than 15% by weight. weight, in particular less than 10% by weight, more particularly less than 5% by weight based on the total weight of the material M2 .

The material M2 may also comprise molybdenum in a content of less than 35% by weight based on the total weight of the material M2 , advantageously less than 30% by weight, preferably less than 20% by weight, more preferably less than 15% by weight. weight, in particular less than 10% by weight, more particularly less than 5% by weight based on the total weight of the material M2 .

Preferably, the material M2 is Monel®, Hastelloy®, Inconel® or Incoloy®.

According to a preferred embodiment, the material M1 comprises at least 70% by weight of iron, advantageously at least 75% by weight, preferably at least 80% by weight, more preferably at least 85% by weight, in particular at least 90% by weight, more particularly at least 95% by weight of iron based on the total weight of the material M1 .

The material M1 can also comprise less than 2% by weight of carbon, advantageously less than 1.5% by weight, preferably less than 1% by weight, more preferably less than 0.75% by weight, in particular less than 0 5% by weight, more particularly less than 0.2% by weight, preferably less than 0.1% by weight based on the total weight of the material M1 . More particularly, the material M1 can comprise between 0.01 and 0.2% by weight of carbon based on the total weight of the material M1 .

Preferably, said base layer and said inner layer are arranged against each other by hot or cold plating, hot or cold rolling or welding.

Example

Example 1

Step a): The equipment used is composed of a 2.0L Hastelloy C276 autoclave, equipped with a pressure indicator, a temperature probe, a bursting disc and a system of stirring by magnetic bar. In the autoclave, successively introduced: 140.0 g (0.55 mol) of iodine, 750.0 g of anhydrous ethanol and 60.0 g (0.52 mol) of CF ₃ -CF=CH ₂ (HFO-1234yf). The reactor is heated to 85° C. for 11 hours, then cooled to room temperature. After degassing, then flushing with helium, the reaction mixture is collected after opening the autoclave. The organic phase is washed then dried and analyzed by gas phase chromatography (area percentage). The analysis confirms the formation of the diiofofluoroalkane compound CF ₃ -CFI-CH ₂ I (95.3% conversion with 96.1% selectivity).

Stage b): A reactor is used consisting of an Inconel 600 tube with an internal diameter of 28 mm and a length of 640 mm, placed vertically in a tube furnace. The catalytic bed consists of a 40 mm lower layer of corundum, then an 85 mm layer of chromium oxyfluoride catalyst containing between 15% and 20% by weight of previously activated fluorine. Passing over this catalyst, at a temperature of 300° C., a gaseous stream composed of the organic phase, washed and then dried from step a) and a gaseous stream of nitrogen (volume ratio 1/2). At the reactor outlet, the gases are scrubbed, then dried and condensed in a cold trap. A sample is taken and analyzed by gas chromatography (area percentage). The yield of CF3-CF=CHI, expressed by the ratio of the number of moles of CF3-CF=CHI detected to the number of moles of HFO-1234yf introduced initially, is 83.8%.

Example 2

Example 1 was reproduced with an intermediate purification of the diiodofluoroalkane compound by distillation to completely eliminate the excess iodine and the impurities. The yield of CF ₃ -CF=CHI after the two reaction stages was approximately 78.7%.

Claims (9)

A method of producing an iodofluoroolefin compound comprising the steps:

1. bringing a fluoroolefin of formula (I) (R ¹ )(R ² )C=CH(R ³ ) into contact with iodine (I ₂ ) in the liquid phase, to form a diiodofluoroalkane compound of formula (II) (R ¹ )(R ² )C(I)-CH(I)(R ³ );
2. dehydroiodination of said diiodofluoroalkane compound of formula (II) obtained in step a) to form a stream B comprising said iodofluoroolefin of formula (III) (R ¹ )(R ² )C=C(I)(R ³ );

the R substituents¹, R²and R³being independently selected from the group consisting of H, F, C-alkyl₁-VS₁₀optionally substituted by at least one fluorine atom, a C cycloalkyl radical₃-VS₁₀optionally substituted by at least one fluorine atom, a C alkenyl radical₂-VS₁₀optionally substituted by at least one fluorine atom, a C cycloalkenyl radical₃-VS₁₀optionally substituted with at least one fluorine atom, and one C aryl radical₆-VS₁₀optionally substituted with at least one fluorine atom; provided that at least one of the substituents R¹, R²or R³either F or either a radical as defined above containing at least one fluorine atom. Process according to the preceding claim, characterized in that R ¹ , R ² and R ³ are independently of one another selected from the group consisting of H, F, a C ₁ -C ₅ perfluoroalkyl radical, a C ₅ - perfluorocycloalkyl radical, C ₁₀ , a C ₂ -C ₅ perfluoroalkenyl radical, a C ₅ -C ₁₀ perfluorocycloalkenyl radical, a C ₆ -C ₁₀ perfluoroaryl radical; provided that R ¹ , R ² and R ³ are not simultaneously H. Process according to Claim 1, characterized in that R ¹ , R ² and R ³ are independently selected from the group consisting of H, F or Y ¹ -[-C(Y ² )(Y ³ )-] _n - in which Y ¹ , Y ² , and Y ³ are, independently of each other and independently for each unit n, selected from the group consisting of H and F; and n is an integer from 1 to 10; provided that at least one of the substituents R ¹ , R ² , R ³ , Y ¹ , Y ² or Y ³ is F. Process according to Claim 1, characterized in that the said fluoroolefin is selected from the group consisting of CHF=CH ₂ , CF ₂ =CH ₂ , CHF=CHF, CF ₂ =CHF, CH ₃ -CF=CH ₂ , CH ₃ -CH =CHF, CH ₂ F-CH=CH ₂ , CH ₃ -CF=CHF, CH ₂ F-CF=CH ₂ , CH ₃ -CH=CF ₂ , CH ₂ F-CH=CHF, CHF ₂ -CH=CH ₂ , CH ₃ -CF=CF ₂ , CH ₂ F-CF=CHF, CHF ₂ -CF=CH ₂ , CH ₂ F-CH=CF ₂ , CHF ₂ -CH=CHF, CF ₃ -CH=CH ₂ , CH ₂ F-CF=CF ₂ , CHF ₂ -CF=CHF, CF ₃ -CF=CH ₂ , CHF ₂ -CH=CF ₂ , CF ₃ -CH=CHF, CHF ₂ -CF=CF ₂ , CF ₃ - CF=CHF, CF ₃ -CH=CF ₂ ; advantageously said fluoroolefin is selected from the group consisting of CF ₂ =CH ₂ , CF ₂ =CHF, CF ₃ -CH=CH ₂ , CF ₃ -CF=CH ₂ , CF ₃ -CH=CHF, CF ₃ -CF=CHF ;
and in that said diiodofluoroalkane compound is selected from the group consisting of CHFI-CH ₂ I, CF ₂ I-CH ₂ I, CHFI-CHFI, CF ₂ I-CHFI, CH ₃ -CFI-CH ₂ I, CH ₃ - CHI-CHFI, CH ₂ F-CHI-CH ₂ I, CH ₃ -CFI-CHFI, CH ₂ F-CFI-CH ₂ I, CH ₃ -CHI-CF ₂ I, CH ₂ F-CHI-CHFI, CHF ₂ -CHI-CH ₂ I, CH ₃ -CFI-CF ₂ I, CH ₂ F-CFI-CHFI, CHF ₂ -CFI-CH ₂ I, CH ₂ F-CHI-CF ₂ I, CHF ₂ -CHI-CHFI, CF ₃ -CHI-CH ₂ I, CH ₂ F-CFI-CF ₂ I, CHF ₂ -CFI-CHFI, CF ₃ -CFI-CH ₂ I, CHF ₂ -CHI-CF ₂ I, CF ₃ -CHI-CHFI , CHF ₂ -CFI-CF ₂ I, CF ₃ -CFI-CHFI, CF ₃ -CHI-CF ₂ I; advantageously said diiodofluoroalkane compound is selected from the group consisting of CF ₂ I-CH ₂ I, CF ₂ I-CHFI, CF ₃ -CHI-CH ₂ I, CF ₃ -CFI-CH ₂ I, CF ₃ -CHI-CHFI, CF ₃ -CFI-CHFI;
and in that said iodofluoroolefin is selected from the group consisting of CFI=CH ₂ , CHF=CHI, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₂ =CF-CH ₂ I, CH ₃ -CF= CHI, CH ₂ =CH-CHFI, CH ₃ -CI=CHF, CH ₃ -CH=CFI, CHF=CH-CH ₂ I, CH ₂ F-CI=CH ₂ , CH ₂ F-CH=CHI, CH ₂ =CF-CHFI, CH ₃ -CF=CFI, CHF=CF-CH ₂ I, CH ₂ F-CF=CHI, CH ₂ =CH-CF ₂ I, CH ₃ -CI=CF ₂ , CHF=CH-CHFI , CH ₂ F-CI=CHF, CH ₂ F-CH=CFI, CF ₂ =CH-CH ₂ I, CHF ₂ -CI=CH ₂ , CHF ₂ -CH=CHI, CH ₂ =CF-CF ₂ I, CHF=CF-CHFI, CH ₂ F-CF=CFI, CF ₂ =CF-CH ₂ I, CHF ₂ -CF=CHI, CHF=CH-CF ₂ I, CH ₂ F-CI=CF ₂ , CF ₂ = CH-CHFI, CHF ₂ -CI=CHF, CHF ₂ -CH=CFI, CF ₃ -CI=CH ₂ , CF ₃ -CH=CHI, CHF=CF-CF ₂ I, CF ₂ =CF-CHFI, CHF ₂ -CF=CFI, CF ₃ -CF=CHI, CF ₂ =CH-CF ₂ I, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₃ -CH=CFI, CF ₂ =CF-CF ₂ I, CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; preferably said iodofluoroolefin is selected from the group consisting of CHI=CHF, CF ₂ =CHI, CFI=CHF, CF ₂ =CFI, CH ₃ -CF=CHI, CH ₃ -CI=CHF, CH ₂ F-CI=CH ₂ , CH ₂ =CF-CHFI, CH ₂ F-CF=CHI, CH ₃ -CI=CF ₂ , CH ₂ F-CI=CHF, CHF ₂ -CI=CH ₂ , CH ₂ =CF-CF ₂ I, CHF=CF-CHFI, CHF ₂ -CF=CHI, CH ₂ F-CI=CF ₂ , CHF ₂ -CI=CHF, CF ₃ -CI=CH ₂ , CHF=CF-CF ₂ I, CHF ₂ -CF= CFI, CF ₃ -CF=CHI, CHF ₂ -CI=CF ₂ , CF ₃ -CI=CHF, CF ₂ =CF-CF ₂ I, CF ₃ -CF=CFI, CF ₃ -CI=CF ₂ ; in particular said iodofluoroolefin is selected from the group consisting of CF ₂ =CHI, CF ₂ =CFI, CF ₃ -CI=CH ₂ , CF ₃ -CF=CHI, CF ₃ -CI=CHF, CF ₃ -CF=CFI. Process according to any one of the preceding claims, characterized in that the stream B also comprises HI, and in that the process comprises a stage of separation between the said iodofluoroolefin and HI. Process according to any one of the preceding claims, characterized in that the said diiodofluoroalkane compound is dried and optionally purified before being implemented in step b). Process according to any one of the preceding claims, characterized in that step a) is carried out in the liquid phase in the presence of a solvent selected from the group consisting of aqueous solutions of potassium iodide, ethers, ethers fluorinated alcohols, fluorinated alcohols, esters, aromatic solvents, fluorinated aromatic solvents, halogenated solvents and mixtures thereof. Process according to any one of the preceding claims, characterized in that step b) is implemented using a basic aqueous mixture, advantageously said mixture comprises a base selected from an alkali or alkaline-earth hydroxide, preferably said mixture has an alkali or alkaline earth hydroxide content of 20 to 80% by weight based on the total weight of said mixture. Process according to any one of the preceding claims 1 to 7, characterized in that step b) is carried out in the gas phase and the said dehydroiodination catalyst is selected from the group consisting of an oxide, an oxyhalide or a halide of a metal or metalloid from columns 4 to 15 of the periodic table, preferably selected from the group consisting of an oxide, an oxyhalide or a halide of aluminium, iron or chromium.