WO2017102055A1 - Method for producing salts with monofluorotricyanoborate anions - Google Patents

Abstract

The invention relates to a method for producing alkali metal salts with monofluorotricyanoborate anions according to formula I, by reaction of a formula II compound with TMS-CN: [Me]⁺ [BF(CN)₃]^- (I), [Me¹]⁺ [BF_n(CN)_4-n]^- (II). The claimed method reacts alkali-metal fluoroborates with trialkylsilyl cyanide and is characterised by the presence of a trialkylsilyl ester of a perfluoralkane sulfonic acid as catalyst, which can optionally be generated in situ, wherein the reaction conditions are selected such that the reaction is carried out at temperatures of 0 °C to 50 °C and both the water content and the acid content are a maximum of 1000 ppm.

Description

 Process for the preparation of salts with

 Monofluorotricyanoboratanionen

The invention relates to a process for the preparation of alkali metal salts with monofluorotricyanoborate anions, preferably from

 Kaliummonofluorotricyanoborat, from Alkalimetallfluoroboraten and

Trialkylsilyl cyanide in the presence of a trialkylsilyl ester

Perfluoralkansulfonsäure, which can be optionally generated in situ, wherein the conditions of the reaction are chosen such that the

Implementation is carried out at temperatures of 0 ° C to 50 ° C and both the water content and the oxygen content is a maximum of 1000 ppm.

Potassium monofluorotricyanoborate is a preferred starting material for the preparation of ionic liquids with monofluorotricyanoborate

Anions. The use of such ionic liquids is varied, as described, for example, in WO 2004/072089 or in WO 2012/041437. They are suitable, for example, as an electrolyte component for electrochemical cells, in particular for dye-sensitized solar cells.

The preparation of alkali metal cyanoborates by reacting an alkali metal cyanide with boron trifluoride etherate is described, for example, in WO

2004/072089 described. When using coarse grained

In addition to the primary adduct K [BF3 (CN)], potassium cyanide and BF3 etherate also form equimolar amounts of K [BF4] and

K [BF2 (CN) 2]. In addition, the two salts potassium monofluorotricyanoborate, K [BF (CN) 3], and potassium tetracyanoborate are formed to a small extent. The reactions were carried out in an aprotic solvent. JP 2004-175666 describes the synthesis of alkali metal trifluorocyanoborate by reacting potassium cyanide in BF 3 etherate at 50 ° C. Alternatively, alkali metal monofluorotricyanoborates can be prepared by reacting an alkali metal tetrafluoroborate with a trialkylsilyl cyanide.

 The reaction of a tetrafluoroborate with trimethylsilyl cyanide is described, for example, in B.H. Hamilton et al., Chem. Commun., 2002, 842-843 or in E. Bernhardt et al., Z. Anorg. Gen. Chem. 2003, 629, 677-685.

In WO 2014/198401 the synthesis of

Alkalimetallmonofluorotricyanoboraten by reaction of

 Alkalimetalltetrafluoroboraten with trimethylsilyl cyanide in the presence of trimethylsilyl chloride as a Lewis acid catalyst described.

In WO 2015/067405 the synthesis of

Alkalimetallmonofluorotricyanoboraten by reaction of

 Alkali metal tetrafluoroborates with trimethylsilyl cyanide in the presence of Lewis acid catalysts described, for example in the presence of GaC, FeC or TiCk However, there remains a need for economic alternative synthetic methods to produce in particular potassium monofluorotricyanoborate.

The object of the present invention is therefore an alternative

Develop manufacturing process.

Surprisingly, it was found that the amount of

Trialkylsilylcyanide can reduce and a smaller amount

Catalyst is necessary, as compared to, for example, the catalysis with trialkylchlorosilane, trialkylbromosilane and / or Triaklyliodsilan when the reaction in the presence of a trialkylsilyl ester of a

Perfluoroalkanesulfonic acid is performed. Furthermore, a decisive advantage in the use of the trialkylsilyl ester of a perfluoroalkanesulfonic acid, that the reaction can be carried out at low temperatures of 0 ° C to 50 ° C at atmospheric pressure.

Alternatively, a combination of the catalysts trialkylchlorosilane, trialkylbromosilane and / or tri-alkyliodosilane and a trialkylsilyl ester of a perfluoroalkanesulfonic acid may also be used, while maintaining the advantage of low temperature at atmospheric pressure of the reaction.

The subject of the invention is therefore a process for the preparation of compounds of the formula I.

[Me] ⁺ [BF (CN) ₃ ] - I,

in which

[Me] ⁺ an alkali metal cation means

by reacting a compound of formula II

[Me] ⁺ [BFn (CN) 4-NJ- II,

wherein Me ¹ represents an alkali metal, which may be the same or different from Me and

n is 2, 3 or 4,

with a trialkylsilyl cyanide in the presence of a trialkylsilyl ester of a perfluoroalkanesulfonic acid, wherein the alkyl groups of the trialkylsilyl cyanide and the trialkylsilyl ester each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms and the perfluoroalkyl group of the sulfonic acid means a linear or branched one

Perfluoroalkyl group having 1 to 4 carbon atoms,

wherein the conditions of the reaction are chosen such that the

Implementation is carried out at temperatures of 0 ° C to 50 ° C and that both the water content and the oxygen content is at most 1000 ppm, and subsequent metal cation exchange, in the event that Me ^{1 is} not Me.

Alkali metals are the metals lithium, sodium, potassium, cesium or rubidium. In compounds of the formula I, [Me] ^{+ is} preferably a cation of sodium or potassium, more preferably of potassium. Accordingly, the process according to the invention is preferably suitable for the synthesis of sodium monofluorotricyanoborate or potassium monofluorotricyanoborate.

The compounds of formula II are commercially available, in particular compounds of formula II in which n is 4, or they are accessible by known synthetic methods.

The preparation of the compounds of the formula II in which n is 2 or 3, as described above, can be carried out, for example, by reacting an alkali metal cyanide with boron trifluoride etherate, as described in WO 2004/072089.

In the compounds of formula II, [Me ¹ ] ^{+ may be} a cation of a

Alkali metal, selected from the group of cations of lithium, sodium, potassium, cesium or rubidium, which is independent of

Alkali metal cation of the final product of formula I is selected. [Me ¹ ] ⁺ in formula II may be the same or different from [Me] ⁺ in formula I.

In compounds of formula II, [Me ¹ ] ^{+ is} preferably a cation of sodium or potassium. In compounds of the formula II, [Me ¹ ] ^{+ is} particularly preferably a sodium cation.

A linear or branched alkyl group having 1 to 10 carbon atoms is, for example, methyl, ethyl, n-propyl, / ^'so-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, RZ Heptyl, n-octyl, ethyl-hexyl, π-nonyl or n-decyl. Trialkylsilyl cyanides are commercially available or are accessible by known synthetic methods.

 The alkyl groups of the trialkylsilyl cyanide may be the same or different. The alkyl groups of the trialkylsilyl cyanide have 1 to 10 C atoms, preferably 1 to 8 C atoms, particularly preferably 1 to 4 C atoms. The alkyl groups of the trialkylsilyl cyanide are preferably the same if they are alkyl groups having 1 to 4 C atoms. An alkyl group of the trialkylsilyl cyanide is preferably different when it is an alkyl group of 5 to 10 C atoms or 5 to 8 C atoms. Suitable examples of trialkylsilyl cyanides are trimethylsilyl cyanide, triethylsilyl cyanide, triisopropylsilyl cyanide, tripropylsilyl cyanide,

Octyldimethylsilylcyanide, butyldimethylsilylcyanide, f-butyldimethylsilylcyanide or tributylsilylcyanide. Particularly preferred trimethylsilyl cyanide is used, which is commercially available or can be prepared in situ.

In the process according to the invention, the trialkylsilyl cyanide, as described above or as preferably described, is selected from the group consisting of trimethylsilyl cyanide, triethylsilyl cyanide, triisopropylsilyl cyanide,

 Tripropylsilyl cyanide, octyldimethylsilyl cyanide, butyldimethylsilyl cyanide, t-butyldimethylsilyl cyanide or tributylsilyl cyanide.

Preferably, the trialkylsilyl cyanide is not prepared in situ.

In the method according to the invention is particularly preferred

Trimethylsilylcyanid used.

Trialkylsilyl esters of perfluoroalkanesulfonic acids are commercially available or are accessible by known synthetic methods. They can also be produced in situ.

Suitable trialkylsilyl esters of perfluoroalkanesulfonic acids for the process of this invention have alkyl groups, each independently are linear or branched and have 1 to 10 carbon atoms, wherein the perfluoroalkyl group of the acid is linear or branched and has 1 to 4 carbon atoms.

 Preferred trialkylsilyl esters of perfluoroalkanesulfonic acids are

Trimethylsilylester of Perfluoralkansulfonsäuren.

In a preferred embodiment of the method, as before

described, the alkyl groups of the trialkylsilyl cyanide and the

Trialkylsilyl esters of perfluoroalkanesulfonic acid methyl groups.

Another object of the invention is therefore a method as described above, wherein the alkyl groups of the trialkylsilyl cyanide and the trialkylsilyl ester mean methyl. Preferred perfluoroalkanesulfonic acids are trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid or

Nonafluorobutanesulfonic acid, wherein the perfluoroalkyl group is preferably linear. In a particularly preferred embodiment of the process, a trialkylsilyl ester of trifluoromethanesulfonic acid or the

Nonafluorobutanesulfonic acid is used, preferably a trimethylsilyl ester of trifluoromethanesulfonic acid or nonafluorobutanesulfonic acid, which may optionally also be prepared in situ.

A further subject of the invention is therefore a process as described above, wherein the trialkylsilyl ester is formed in situ as described above or described as preferred. The trialkylsilyl ester of perfluoroalkanesulfonic acid can be used, for example, in situ by reaction of the trialkylsilyl cyanide used and / or by reaction of a trialkylchlorosilane with a correspondingly employed Perfluoroalkanesulfonic acid, with an anhydride of the used

Perfluoroalkanesulfonic acid or with an alkyl ester of a

Perfluoralkansulfonsäure be prepared, wherein the alkyl group of the alkyl ester is methyl or ethyl.

Preference is therefore given to a trimethylsilyl ester of trifluoromethanesulfonic acid in situ by reaction of trifluoromethanesulfonic acid with trialkylsilyl cyanide, preferably with trimethylsilyl cyanide, by reaction of

Trifluoromethanesulfonic anhydride with trialkylsilyl cyanide, preferably with trimethylsilyl cyanide, by reaction of methyl trifluoromethanesulfonate with trialkylsilyl cyanide, preferably with trimethylsilyl cyanide, or with

Ethyl trifluoromethanesulfonate with trialkylsilyl cyanide, preferably with

Trimethylsilylcyanid be prepared. Therefore, a trimethylsilyl ester of

 Nonafluorobutanesulphonic acid in situ by reaction of

Nonafluorobutanesulfonic acid with trialkylsilyl cyanide, preferably with

Trimethylsilyl cyanide, by reaction of

 Nonafluorobutanesulfonic anhydride with trialkylsilyl cyanide, preferably with trimethylsilyl cyanide, by reaction of methyl nonafluorobutanesulfonate with trialkylsilyl cyanide, preferably with trimethylsilyl cyanide, or with

Ethylnonafluorbutansulfonat with trialkylsilyl cyanide, preferably with

Trimethylsilylcyanid be prepared. Particularly preferred is trimethylsilyl trifluoromethanesulfonate or

 Trimethylsilylnonafluorbutansulfonat used or generated in situ. Very particular preference trimethylsilyl trifluoromethanesulfonate is used or generated in situ. Particularly preferred is the trialkylsilyl ester of

 Perfluoroalkanesulfonic acid, as previously described or preferred

described, used in an amount of 0.5 to 30 mol%, based on the amount of trialkylsilyl cyanide used. Particular preference is given to using the trialkylsilyl ester of perfluoroalkanesulfonic acid, as described above or preferably described, in an amount of from 2 to 12 mol%, based on the amount of trialkylsilyl cyanide used. Very particular preference is given to the trialkylsilyl ester of

 Perfluoroalkanesulfonic acid, as previously described or preferred

described, used in a total amount of 3 to 7 mol%, based on the amount of trialkylsilyl cyanide used. The invention therefore furthermore provides the process as described above or described as being preferred, wherein the trialkylsilyl ester of perfluoroalkanesulfonic acid, as described or preferably described above, is used in an amount of 0.5 to 30 mol%, based on the amount of used trialkylsilyl cyanide.

If the trialkylsilyl ester in situ by reaction of a

Perfluoroalkanesulfonic acid with the trialkylsilyl cyanide produced as described above or preferably described, the corresponding perfluoroalkanesulfonic acid is preferably used in an amount of 0.5 to 10 mol%, particularly preferably in an amount of 2 to 4 mol%, based on the amount of the used Trialkylsilylcyanids.

If the trialkylsilyl ester is generated in situ by reacting an anhydride of a perfluoroalkanesulfonic acid with the trialkylsilyl cyanide, as previously described or preferably described, the corresponding

Perfluoralkansulfonsäureanhydrid preferably used in an amount of 0.5 to 10 mol%, more preferably in an amount of 2 to 4 mol%, based on the amount of trialkylsilyl cyanide used. If the trialkylsilyl ester is generated in situ by reacting a methyl ester or ethyl ester of perfluoroalkanesulfonic acid with the trialkylsilyl cyanide, as described above or preferably described, the corresponding methyl esters or ethyl esters of perfluoroalkanesulfonic preferably used in an amount of 1 to 10 mol%, particularly preferably in an amount of 3 to 7 mol%, based on the amount of

used trialkylsilyl cyanide.

Another object of the invention is therefore a method for

Preparation of compounds of the formula I

[Me] ⁺ [BF (CN) ₃ ] - I,

in which

[Me] ⁺ an alkali metal cation means

by reacting a compound of formula II

[Me] ⁺ [BF _n (CN) 4-n] - II,

wherein Me means an alkali metal which may be the same or different than Me and

n is 2, 3 or 4,

with a trialkylsilyl cyanide in the presence of an alkyl ester of a

Perfluoroalkanesulfonic acid, wherein the alkyl groups of Trialkylsilylcyanids each independently a linear or branched alkyl group having 1 to 10 carbon atoms, the alkyl group of the alkyl ester means methyl or ethyl and the perfluoroalkyl group of sulfonic acid means a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms wherein the conditions of the reaction are chosen such that the reaction is carried out at temperatures of 0 ° C to 50 ° C and that both the water content and the oxygen content are at most 1000 ppm, and then metal cation exchange, in the case that Me ¹ not Me equals.

The preferred reaction temperature for this in situ generation are temperatures of 10 ° C to 50 ° C.

Another object of the invention is therefore the method as described above or described as preferred, wherein the methyl ester or - 1Ό -

Ethyl ester of perfluoroalkanesulfonic acid, as described above or preferably described, is used in an amount of 1 to 10 mol%, based on the amount of trialkylsilyl cyanide used. Another object of the invention is therefore a method for

Preparation of compounds of the formula I

[Me] ⁺ [BF (CN) ₃ ] - I,

in which

[Me] ⁺ an alkali metal cation means

by reacting a compound of formula II

[Me ¹ ] ⁺ [BFn (CN) ₄ -n] - II,

wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

n is 2, 3 or 4,

with a trialkylsilyl cyanide in the presence of a perfluoroalkanesulfonic acid, wherein the alkyl groups of Trialkylsilylcyanids each independently a linear or branched alkyl group having 1 to 10 carbon atoms and the perfluoroalkyl group of sulfonic acid means a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms, wherein the Conditions of the reaction are chosen such that the reaction at temperatures from 0 ° C to 50 ° C are performed and that both the water content and the oxygen content of 1000 ppm maximum, and subsequent metal cation exchange, in the event that Me ^{1 is} not Me ,

The preferred reaction temperature in this in situ generation are temperatures from 0 ° C to 40 ° C.

Another object of the invention is therefore the method as described above or described as preferred, wherein the

Perfluoroalkanesulfonic acid, as previously described or preferred is used in an amount of 0.5 to 10 mol%, based on the amount of trialkylsilyl cyanide used.

Another object of the invention is therefore a method for

Preparation of compounds of the formula I

[Me] ⁺ [BF (CN) ₃ ] - I,

in which

[Me] ⁺ an alkali metal cation means

by reacting a compound of formula II

[Me ¹ ] ⁺ [BFn (CN) ₄ -n] - II,

wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

n is 2, 3 or 4,

with a trialkylsilyl cyanide in the presence of an anhydride

Perfluoroalkanesulfonic acid, wherein the alkyl groups of Trialkylsilylcyanids each independently a linear or branched alkyl group having 1 to 10 carbon atoms and the perfluoroalkyl of the

Sulfonic anhydride means a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms,

wherein the conditions of the reaction are chosen such that the reaction is carried out at temperatures of 0 ° C to 50 ° C and that both the water content and the oxygen content are at most 1000 ppm, and subsequent metal cation exchange, in case Me ^{1 is} not Me corresponds.

The preferred reaction temperature for this in situ generation are temperatures of 10 ° C to 50 ° C.

The invention therefore furthermore provides the process as described above or described as being preferred, wherein the anhydride of the perfluoroalkanesulfonic acid is as previously described or preferred is used in an amount of 0.5 to 10 mol%, based on the amount of trialkylsilyl cyanide used.

Regardless of which embodiment of the method according to the invention is chosen, it is preferred to use the starting materials in one

 Inertgasatmosphäre mix whose oxygen content is at most 1000 ppm. It is particularly preferred if the oxygen content is smaller

500ppm, most preferably at most 00ppm.

 The water content of the reagents and the inert gas atmosphere is at most 1000 ppm. It is particularly preferred if the water content of the reagents and the atmosphere is less than 500 ppm, quite

more preferably at most 100 ppm.

 The conditions regarding the water content and the oxygen content do not apply to the processing after successful implementation of the

Compound of the formula II with the trialkylsilyl cyanide.

In a preferred embodiment of the process according to the invention, irrespective of whether the trialkylsilyl ester of perfluoroalkanesulfonic acid is used directly or is generated in situ, a compound of the formula II in which n is 2 or 4 is used.

Another object of the invention is therefore the inventive method, as described above or described in its embodiments, characterized in that a compound of formula II is used, in which n is 2 or 4.

Particularly preferred compounds of formula II are

Alkali metal tetrafluoroborates (n = 4), especially sodium tetrafluoroborate. Another object of the invention is therefore the inventive method, as described above or in its embodiments described, characterized in that a compound of formula II is used, in which n is 4.

In an alternative embodiment of the invention, it is preferred to first the compound of formula II and the trialkylsilyl cyanide in

To react present of a trialkyl, Trialkylbrom- and / or Trialkyliodsilan and subsequently the reaction mixture with the

Implement trialkylsilyl ester of perfluoroalkanesulfonic.

Preferably, the reaction mixture is stirred with the silane (s) for several hours at 25 ° C to 45 ° C, before the addition of the trialkyl ester of perfluoroalkanesulfonic occurs.

The invention therefore further provides the process according to the invention, as described above or described in its embodiments, characterized in that the compound of the formula II and the trialkylsilyl cyanide are first dissolved in the presence of trialkylchloride,

Trialkylbrom- and / or Trialkyliodsilan is reacted and the reaction subsequently in the presence of a trialkylsilyl ester of a

Perfluoroalkanesulfonic acid is completed, wherein the alkyl groups of Trialkylchlor- Trialkylbrom- and / or Trialkyliodsilans each independently a linear or branched alkyl group having 1 to 10 carbon atoms.

The trialkylchlorosilane, trialkylbromosilane or trialkyliodosilane is commercially available or can be prepared by standard methods.

Trialkylbromosilane or trialkyliodosilane can be prepared in situ from

Trialkylchlorosilane and an alkali metal bromide or alkali metal iodide. Suitable trialkylsilyl chlorides for the process according to the invention (or synonymously trialkylchlorosilanes), trialkylsilyl bromides (synonymous with trialkylbromosilanes) and / or trialkylsilyl iodides (synonymous thereto Trialkyliodosilanes) have alkyl groups which are each independently linear or branched and have 1 to 10 carbon atoms.

The alkyl groups of the trialkylsilyl halide may be the same or

to be different. The alkyl groups of the trialkylsilyl halide preferably have 1 to 8 C atoms, particularly preferably 1 to 4 C atoms. The alkyl groups of the trialkylsilyl halide are preferably the same if they are alkyl groups having 1 to 4 carbon atoms. An alkyl group of the trialkylsilyl halide is preferably different when it is an alkyl group of 5 to 10 C atoms or 5 to 8 C atoms.

Preferably, the trialkylsilyl halide is a trialkylsilyl chloride.

Suitable trialkylsilyl chlorides are trimethylsilyl chloride (or synonymously trimethylchlorosilane), triethylsilyl chloride, triisopropylsilyl chloride,

 Tripropylsilyl chloride, octyldimethylsilyl chloride, butyldimethylsilyl chloride, t-butyldimethylsilyl chloride or tributylsilyl chloride. Particular preference is given to using trimethylsilyl chloride. Very particularly preferred

Trimethylsilyl chloride used alone.

Suitable trialkylbromosilanes are trimethylbromosilane (or synonymously trimethylsilylbromide), triethylsilylbromide, triisopropylsilylbromide,

Tripropylsilylbromide, octyldimethylsilylbromide, butyldimethylsilylbromide, t-butyldimethylsilylbromide or tributylsilylbromide. Particularly preferred trimethylsilyl bromide is used in admixture with trimethylsilyl chloride.

Suitable trialkyliodosilanes are trimethyliodosilane (or synonymously trimethylsilyl iodide), triethylsilyl iodide, triisopropylsilyl iodide,

Tripropylsilyl iodide, octyldimethylsilyl iodide, butyldimethylsilyl iodide, t-butyldimethylsilyl iodide or tributylsilyl iodide. Particularly preferred trimethylsilyliodi is used in admixture with trimethylsilyl chloride. Another object of the invention is therefore the alternative method, as described above or described as preferred, wherein the

Trialkylchlor, Trialkylbrom- and / or Trialkyliodsilan, as before

described or preferably described, is used in an amount of 1 to 20 mol%, based on the amount of the used

 Trialkylsilylcyanids and the trialkylsilyl ester of perfluoroalkanesulfonic acid, as described above, in an amount of 0.5 to 0 mol%, based on the amount of trialkylsilyl cyanide used. Particular preference is given to using the trialkylsilyl halide or a mixture of trialkylsilyl halides in a total amount of from 3 to 12 mol%, based on the amount of trialkylsilyl cyanide used. Very particular preference is given to the trialkylsilyl halide or a

Mixture of trialkylsilyl halides used in a total amount of 7 to 11 mol%, based on the amount of the used

Trialkylsilylcyanids.

In the method according to the invention and its embodiments, as described above, the reaction time is usually from 2 to 12 hours, the actual reaction time of course also depending on the amount of catalyst selected.

In the method according to the invention, as described above or in

Embodiments as described or preferred described, the reaction of the compound of formula II, as described above or described as preferred, takes place without organic solvent or in the presence of an organic solvent. Suitable solvents are acetonitrile, propionitrile or benzonitrile. A particularly suitable solvent for the reaction described is acetonitrile.

In a preferred embodiment of the process according to the invention, the reaction of the formula II with trialkylsilyl cyanide takes place in the presence of Catalyst without organic solvent instead. This also applies to the

Embodiments of in situ generation of the catalyst.

Another object of the invention is therefore the inventive method, as described above, wherein the reaction of the compound of formula II, as described above or hereinafter as preferred

described, takes place in the presence of an organic solvent or without an organic solvent. The inventive method, as described above, in his

Embodiments described or described as being preferred will be either in an open device or in a closed one

Device performed.

 In the reaction in an open reaction apparatus as

Device, appropriate measures must be taken to remove the resulting trialkylsilyl fluoride from the reaction. Such measures are known to the person skilled in the art. Suitable measures are described in the examples section.

 When carrying out the reaction in a closed reaction apparatus as a device, the reaction takes place at a maximum overpressure of 0.5 bar.

Another object of the invention is therefore the method as described above, characterized in that the reaction takes place in an open or in a closed device.

In a preferred embodiment of the method according to the invention, as described or preferred described above, the

Trialkylsilylester of perfluoroalkanesulfonic acid, either alone

Catalyst or in admixture with previously known catalysts, at 0 ° C to 25 ° C was added and then to the corresponding End temperature of the reaction is heated, as described above and if necessary for the completeness of the reaction.

If the trialkylsilyl ester of perfluoroalkanesulfonic acid is generated in situ, the corresponding perfluoroalkanesulfonic acid, the corresponding perfluoroalkanesulfonic anhydride or the corresponding methyl or ethyl ester of perfluoroalkanesulfonic acid are likewise added at 0 ° C. to 25 ° C. and then heated to the corresponding final temperature of the reaction, as described above , However, cooling in the temperature range of 0 ° C to -196 ° C is also possible.

In the method according to the invention, independently in which

Embodiment, as described above, it is further preferred if the reaction of the reactants followed by a purification step to separate the end product of formula I, as described above, from by-products or reaction products.

 Suitable purification steps include the separation of volatile components by distillation or condensation, extraction with an organic solvent, or a combination of these methods. Any known separation method can be used or combined for this purpose.

Another object of the invention is therefore the method as described above, characterized in that the reaction

Purification step follows.

Should a metal cation exchange after the implementation of the

Compound of formula II with the specified reactants, as described above and below, be necessary because the

corresponding alkali metal cation [Me ⁺ ] for the target product of formula I is not yet contained in the reaction mixture, it is in one

Embodiment of the invention preferred when the Alkali metal cation exchange takes place during the purification step.

A preferred method for the alkali metal cation exchange is, for example, to free the reaction mixture obtained from the reaction at room temperature from volatile components, for example by separation in vacuo, or precipitated crude product

filter off, then add water or a suitable organic solvent and add to this mixture a corresponding carbonate (Me) 2CÜ3 and / or a corresponding hydrogencarbonate MeHCO3, wherein Me corresponds to the alkali metal cation [Me ⁺ ] of the desired end product of the formula I.

 Preferably, both water and at least one organic solvent is used, for example acetonitrile, so that a

Two-phase system trains. Further addition of the corresponding

 Carbonate completes the cation exchange and simultaneously causes the product to go into the organic phase. The desired end product of the formula I is contained in the organic phase. After separation of existing solid, the organic solvent or solvent mixture is distilled off and the product is dried under a fine vacuum. Suitable solvents are acetonitrile, tetrahydrofuran, acetone, diethyl ether, methyl t-butyl ether or dimethoxyethane. Particular preference is given to using acetonitrile. Alternatively, one can precipitate the crude product from the organic phase by adding suitable solvents. Suitable solvents for the precipitation of the crude product from the organic phase are chloroform, dichloromethane, pentane, hexane or toluene. Dichloromethane is particularly preferably used for the precipitation.

An alternative method for the alkali metal cation exchange, for example, the reaction of the resulting reaction mixture with a corresponding carbonate (Me) 2CO3 and / or a

corresponding bicarbonate MeHCO3, where Me the

Alkali metal cation [Me ⁺ ] of the desired end product of the formula I corresponds.

Preferably, the reaction mixture obtained from the reaction is cooled to room temperature and all volatile components are removed in vacuo. The resulting solid is subsequently

preferably with aqueous hydrogen peroxide solution (35%),

optionally water, and the corresponding carbonate (Me) 2CO3 and / or the corresponding bicarbonate MeHCO3 added, wherein Me corresponds to the alkali metal Me of the desired end product of the formula I. Subsequently, the excess peroxide is decomposed by adding a corresponding Alkalimetalldisulfits and with a

extracted suitable organic solvent.

Suitable solvents are ethers, such as tetrahydrofuran, diethyl ether, methyl t-butyl ether or dimethoxyethane, acetonitrile or acetone. Particular preference is given to using tetrahydrofuran, acetonitrile or acetone. The alkali metal in the corresponding disulfite preferably corresponds to the

Alkali metal Me of the desired end product of the formula I.

In an alternative method of purification, the reaction mixture is cooled to room temperature and filtered under inert gas atmosphere or the supernatant solution poured off. Subsequently, the solid is dried in vacuo and possibly on Alkalimetallmonofluortricyanoborat coordinated Trialkylsilylcyanid is separated. The remaining solid is then taken up in water and hydrogen peroxide solution and with the appropriate carbonate (Me) 2CO3 and / or the

corresponding MeHCO3 bicarbonate, wherein Me corresponds to the alkali metal Me of the desired end product of the formula I. The further work-up takes place as described above. Regardless of which purification method is chosen, as described above, the end product of formula I can be precipitated by adding an organic solvent in which the final product is insoluble or the solvent used for extraction is distilled off.

The final product obtained is then dried and characterized by conventional methods.

Another object of the invention is therefore the inventive method, as described above, wherein the metal cation exchange, preferably the alkali metal cation exchange, during the

Purification step takes place.

Another object of the invention is therefore the inventive method, as described above, wherein the metal cation exchange is carried out by reaction with the compound (Me2) CO3 and / or the compound MeHC03, wherein Me corresponds to the Alkalimetalllation [Me ⁺ ] of the desired end product of the formula I. ,

The obtained substances are characterized by NMR spectra. The NMR spectra are measured on solutions in deuterated acetone-D6 or in CD3CN on a Bruker Avance 200 spectrometer or a Bruker DPX spectrometer with deuterium lock. The measurement frequencies of the different cores are: ¹ H (199.93 MHz or 400.40 MHz), ⁹ F (188.09 MHz or 376.70 MHz), ¹¹ B (64.14 MHz or 128.46). The

Referencing done with an external reference: ¹ H-NMR: TMS

(Residual proton signal of acetone-D ₆ : 2.05 ppm); ¹⁹ F-NMR: CICF3, ¹¹ B-NMR: BF ₃ etherate.

Example 1. Synthesis of K [BF (CN) ₃ ]

NaBF _{4 +} 3 (CH ₃ ) ₃ SiCN K [BF (CN) ₃ ]

Na [BF ₄ ] (1.0 g, 9.11 mmol) is initially charged and dissolved in acetonitrile (6 mL).

added. The suspension is first treated with trimethylsilyl cyanide

(TMSCN), Me3SiCN (4.25 mL, 31.87 mmol) and then with

Trimethylsilyltrfluoromethanesulfonate (TMSOTf), Me3SiOS02CF ₃ , (1.0 mL, 5.53 mmol, 17 mol% based on TMSCN). The reaction is stirred overnight at room temperature. Subsequently, the

Toluene (20 mL) and the resulting brown

The residue is filtered off, dried in a fine vacuum (to 10 ³ mbar) and then taken up in water (20 ml). It is mixed with K2CO3 and H2O2 and stirred for several hours. The water is removed with a rotary evaporator (water bath temperature 40-45 ° C). The solid obtained is taken up in acetone, treated with K 2 CO 3 (10 g) and stirred for 20 minutes. The acetone phase is removed and then extracted a further 3 times with acetone. The combined 4 acetone phases are dried with K2CO3, filtered and concentrated in vacuo to a residual volume of about 3 mL. By adding CH2Cl2 (25 mL)

K [BF (CN) 3] precipitated. This is filtered off and in a fine vacuum

dried.

 Yield of K [BF (CN> 3)]: 0.93 g (6.33 mmol, 69% based on the

used borate.

The product is determined by NMR spectroscopy ( ¹ B and ¹⁹ F NMR)

characterized.

¹⁹ F-NMR (solvent Mitel: acetone-de) δ, ppm: -212.10 q, ¹ JH B, I 9F = 44.4 Hz.

1 ¹ B-NMR (solvent: acetone-De), δ, ppm: -17.7 d, ¹ JH B, 19 F = 44.4 Hz.

The spectra correspond to those from the literature [E. Bernhardt, M.

Berkei, H. Willner, M. Schürmann, Z. Anorg. Gen. Chem., 2003, 629, 677-685].

Example 2. Synthesis of K [BF (CN) ₃ ]

NaBF _{4 +} 3 (CH ₃ ) ₃ SiCN K [BF (CN) ₃ ]

Na [BF ₄ ] (1.0 g, 9.11 mmol) is suspended in TMSCN (11.0 mL, 82.49 mmol). Trimethylsilyl trifluoromethanesulfonate, TMSOTf (1.0 mL, 5.53 mmol, 6.7 mol% based on TMSCN) is added and the

The reaction mixture is stirred for 3 h at RT (25-30 ° C). A dark brown-black suspension is obtained. All volatiles are condensed off in a fine vacuum, and the dark brown-black residue is dried to a pressure of 3 × 10 ^-3 mbar, which is dissolved in H 2 O 2 (35%, 10 mL), the solution is added portionwise with K 2 CO 3 (3 g All volatile constituents are removed using a rotary evaporator (bath temperature 45 ° C., up to about 40 mbar) and the residue is then extracted with acetone (3 ^× 20 ml) The combined acetone phases are dried with K 2 CO 3 and filtered It is then concentrated to about 5-10 mL residual volume using a rotary evaporator (bath temperature 45 ° C., about 400 mbar), colorless KMFB is precipitated by addition of CH 2 Cl 2 (60 mL), which is filtered off and dried in a fine vacuum (3 × 10 ³ mbar) ,

 Yield: 1.34 g (9.52 mmol), almost quantitative yield based on the borate used.

The product is characterized by NMR spectroscopy ( ¹¹ B and ¹⁹ F NMR). The spectra correspond to those from the literature.

Example 3. Synthesis of K [BF (CN) ₃ ]

Analogously to Example 2, Na [BF ₄ ] (1.0 g, 9.11 mmol) is suspended in TMSCN (10.0 mL, 74.95 mmol). Trimethylsilyl trifluoromethanesulfonate, TMSOTf (1.0 mL, 5.53 mmol, 7.4 mol% based on TMSCN) is added and the reaction mixture is stirred at room temperature. After 45 minutes, a 90% conversion to Na [BF (CN) 3] is determined by ¹ B-NMR. With further stirring overnight, the degree of conversion reaches> 99%. The conversion to K [BF (CN) 3], substance isolation and characterization is carried out in accordance with the description of Example 2.

Example 4. Synthesis of K [BF (CN) ₃ ] Analogously to Example 2, Na [BF ₄ ] (1.0 g, 9.11 mmol) is suspended in TMSCN (10.0 ml, 74.95 mmol). Trimethylsilyl trifluoromethanesulfonate, TMSOTf (0.5 ml, 2.77 mmol, 3.7 mol% based on TMSCN) is added and the reaction mixture is stirred at room temperature. After 45 minutes, an 87% conversion to Na [BF (CN) 3] was determined by means of ¹¹ B-NMR. With further stirring overnight, the degree of conversion reaches> 98%. The conversion to K [BF (CN) 3], substance isolation and characterization is carried out according to the description of Example 2. Example 5. Synthesis of K [BF (CN) ₃ ]

Analogously to Example 2, Na [BF4] (1.0 g, 9.11 mmol) is suspended in TMSCN (10.0 ml, 74.95 mmol). Trimethylsilyl trifluoromethanesulfonate, TMSOTf (0.2 mL, 1.1 mmol, 1.5 mol% based on TMSCN) is added and the reaction mixture is stirred at room temperature. After 45 minutes, an 86% conversion to Na [BF (CN) 3] was determined by ¹¹ B NMR. With further stirring overnight, the degree of conversion reaches> 96%. The conversion to K [BF (CN) 3], substance isolation and characterization is carried out according to the description of Example 2. Example 6. Synthesis of K [BF (CN) ₃ ]

Analogously to Example 2, Na [BF ₄ ] (1.0 g, 9.11 mmol) is suspended in TMSCN (10.0 mL, 74.95 mmol). Trimethylsilyl trifluoromethanesulfonate, TMSOTf (0.1 mL, 0.55 mmol, 0.7 mol% based on TMSCN) is added and the reaction mixture is stirred at room temperature.

After 45 minutes, a 63% conversion to Na [BF (CN) 3] is determined by means of ¹ B-NMR. With further stirring overnight, the achieved

Degree of conversion> 96%. The conversion to K [BF (CN) 3], substance isolation and characterization is carried out in accordance with the description of Example 2.

Example 7. Synthesis of K [BF (CN) ₃ ]

Synthesis 1: Na [BF ₄ ] (10.0 g, 91.1 mmol) is suspended in trimethylsilyl cyanide (TMSCN; 100.0 mL, 749.9 mmol). The suspension is with

Trimethylsilyltrifluormethansulfonat, Me3SiOSO2CF ₃ (TMSOTf; 3.0 mL, 16.6 mmol, 2.2 mol% based on TMSCN) and in a

closed reaction vessel stirred for 4.5 hours at room temperature.

The resulting black suspension is filtered inert and the filtrate is stored for further reaction (synthesis 2). The light brown solid is dissolved in acetonitrile (50 mL) and then the solution is treated with / -PrOH (0.5 mL). After 5 minutes, the solution is treated with H2O (3 mL) and K2CO3 (5 g). The suspension is stirred for 30 min at room temperature. The resulting colorless liquid upper phase is separated off. The remaining acetonitrile phase is decanted over the obtained sediment. The residual solid is extracted again with acetonitrile (5 × 20 ml). The combined acetonitrile are dried with K2CO3, filtered and the filtrate with a rotary evaporator (bath temperature 45 ° C, pressure about 400 mbar) to about 10-15 mL residual volume concentrated. Addition of CH 2 Cl 2 (100 mL) precipitates K [BF (CN) 3]. This is filtered off and dried in a fine vacuum (3 × 10 ^-3 mbar).

Yield of K [BF (CN) 3)]: 11.0 g (74.83 mmol), corresponding to 82% based on the borate used.

Synthesis 2: (using the filtrate from Synthesis 1)

Na [BF ₄ ] (10.0 g, 91.1 mmol) is suspended in trimethylsilyl cyanide (TMSCN; 40.0 mL, 299.9 mmol). The suspension is precipitated with the filtrate

Synthesis 1 and without addition of further

 Trimethylsilyl trifluoromethanesulfonate (Me3SiOSO2CF3) for 5 hours

Room temperature stirred. Resulting trimethylsilyl fluoride, TMSF, is meanwhile continuously discharged through a bubble counter. The resulting suspension is filtered inert and the filtrate for further

Conversations kept. The filtered solid is taken up in acetonitrile (100 mL), treated with / -PrOH (0.5 mL) and stirred for 10 min. Then K 2 CO ₃ (5 g) and H2O (4 mL) was added The suspension is about 5 Stirred at room temperature for min. The resulting colorless liquid upper phase is separated off. The remaining acetonitrile phase is decanted over the obtained sediment. The residual solid is extracted again with acetonitrile (3 × 25 ml). The combined acetonitrile phases are dried with K 2 CO 3. The suspension is filtered and the filtrate with a rotary evaporator (bath temperature 45 ° C, pressure about 400 mbar) to about 15-20 mL remaining volume concentrated. Addition of CH 2 Cl 2 (100 mL) precipitates K [BF (CN) ₃ ]. This is filtered (frit pore 4) and under high vacuum (3 x 10 ^-3 mbar).

Yield of K [BF (CN) ₃ )]: 13.8 g (93.87 mmol), corresponding to 103% based on the borate used. The yield is over 100% because a small amount of product has entered the system through the filtrate of Synthesis 1. Total yield of K [BF (CN) ₃ )] from both syntheses: 24.8 g (168.7 mmol), corresponding to 92.6%.

 Catalyst (TMSOTf) Charge: 3.0 mL, 16.6 mmol, corresponding to 1.6 mol% based on TMSCN;

 Trimethylsilyl cyanide (TMSCN) charge: 140.0 mL, 1050 mmol; corresponds to 1.92 equivalents for a cyano group.

Example 8. Synthesis of K [BF (CN) ₃ ]

K [BF ₄ ] (1.146 g, 9.11 mmol) is suspended in trimethylsilyl cyanide, (TMSCN, 10.0 mL, 74.99 mmol) and Me3SiOSO 2 CF ₃ (0.3 mL, 1.66 mmol, 2.2 mol% based on TMSCN) is added. The mixture is stirred for 24 hours at 40 ° C. All volatiles are removed in vacuo and the residue taken up in acetonitrile (5 mL). Add H2O (0.5 mL) and K2CO3 (1 g) and then remove the acetonitrile solution above the sediment. The remaining sediment is extracted with acetonitrile (5 mL) and the combined acetonitrile phases are dried with K2CO3, filtered and concentrated with a rotary evaporator to a volume of about 3-4 mL. Then CH2CI2 (10 mL) added and the precipitated product is filtered off and dried in vacuo (to about 3 x 10 ^"2 mbar).

 Yield: 1.15 g (7.82 mmol, corresponding to 80%, based on the borate used).

The product is determined by NMR spectroscopy ( ¹¹ B and ¹⁹ F NMR)

characterized. The spectra correspond to those from the literature.

Example 9. Synthesis of K [BF (CN) 3]

K [BF ₂ (CN) ₂ ] (3.0 g, 21.44 mmol) is suspended in trimethylsilyl cyanide (TMSCN, 15.0 mL, 112.49 mmol) and Me3SiOSO 2 CF ₃ (0.6 mL, 3.32 mmol, 3 mol% based on TMSCN) is added. The reaction mixture is stirred for 2 hours at 25-27 ° C. Subsequently, all become volatile

Remove components in vacuo and dissolve the residue in acetonitrile (10 mL). The solution is treated with / PrOH (1.5 mL) and K2CO3 (3-4 g) is added. The suspension is filtered and the filtrate with a

Rotary evaporator concentrated to dryness. The residue is rinsed with CH 2 Cl 2 (15 mL) on a frit, filtered off and dried in a fine vacuum (to about 3 × 10 ^-3 mbar) Yield: 3.03 g (20.61 mmol, corresponding to 96% based on the borate used).

The product was characterized by NMR spectroscopy ( ¹¹ B and ¹⁹ F NMR). The spectra correspond to those from the literature.

Example 10. Synthesis of K [BF (CN) ₃ ] NaBF ₄ + 3 (CH ₃ ) ₃ SiCN K [BF (CN) ₃ ]

Na [BF4] (0.5 g, 4.55 mmol) is suspended in trimethylsilyl cyanide, TMSCN (5.5 mL, 41.24 mmol). Methyl trifluoromethanesulfonate, CF3SO2OCH3 (0.2 mL, 1.82 mmol, 4.4 mol% based on TMSCN) is added and the suspension is stirred at RT for 2 h. Subsequently, the

 Reaction mixture 12 hrs. At 40 ° C (oil bath temperature) in one

stirred closed flask. The resulting suspension is treated with toluene (15 mL). The precipitated crude product is filtered off and in

Fine vacuum (3 ^{χ 1Ό "3} mbar). The crude product is taken up in H2O (2 mL) and the solution was mixed with stirring with K2CO3 (1 g). Then, acetonitrile (15 mL) is added. This imagines

Two-phase system (h O / acetonitrile). Additional K 2 CO 3 (about 5 g) is added in portions until no more aqueous phase is present. The acetonitrile solution over the solid (mainly K 2 CO 3) is decanted and concentrated to dryness using a rotary evaporator. The resulting solid is dried in a fine vacuum (3 ^× 10 ^-3 mbar) Yield of K [BF (CN) 3]: 536 mg (3.65 mmol, 80% yield with respect to the Na used [BF 4]).

The product was characterized by NMR spectroscopy ( ¹ B and ¹⁹ F NMR). The spectra correspond to those from the literature. Example 11. Synthesis of K [BF (CN) ₃ ]

NaBF ₄ - 3 (CH ₃ ) ₃ SiCN K [BF (CN) ₃ ]

Na [BF ₄ ] (0.5 g, 4.55 mmol) is suspended in trimethylsilyl cyanide, TMSCN (5.5 mL, 41.24 mmol). The suspension is cooled to -196 ° C and the trimethylsilyl ester of nonafluorobutylsulfonic acid, C FgS020Si (CH3) 3 (0.6 g, 1.61 mmol, 3.9 mol% based on TMSCN) is condensed.

The reaction mixture is then stirred for 2 hours at room temperature and then for 12 hours at 40 ° C. (oil bath temperature) in a sealed flask. The resulting suspension is treated with toluene (15 mL). The precipitated crude product is filtered off and under high vacuum (3 ^χ 10 ^-3 mbar). The crude product is taken up in H2O (2 mL) and the solution is added with stirring K2CO3 (1 g). Then acetonitrile (15 mL) is added. This forms a two-phase system (HFEO / acetonitrile). Additional K 2 CO 3 (about 5 g) is added in portions until no more aqueous phase is present. The acetonitrile solution over the solid

(mainly K2CO3) is decanted and with a rotary evaporator concentrated to dryness. The resulting solid is dried in a fine vacuum (3 × 10 ^-3 mbar).

 Yield of K [BF (CN) 3]: 597 mg (4.06 mmol, 89% yield with respect to the Na used [BF4]).

The product was characterized by NMR spectroscopy (B and ¹⁹ F NMR). The spectra correspond to those from the literature.

Example 12. Synthesis of K [BF (CN) ₃ ]

C ₄ FgS (0) ₂ OH (cat.) Κ-, ΓΟ,

NaBF ₄ + 3 (CH ₃ ) ₃ SiCN »Na [BF (CN) ₃ ] K [BF (CN) ₃ ]

Na [BF4] (0.5 g, 4.55 mmol) is suspended in trimethylsilyl cyanide, TMSCN (5.5 mL, 41.24 mmol). The suspension is with

Nonafluorobutanesulfonic acid, C4F9SO2OH (0.2 ml, 1.20 mmol, 2.9 mol% based on TMSCN) and stirred for 2 hours at room temperature.

Subsequently, the reaction mixture is 12 hrs. At 40 ° C.

(Oil bath temperature) stirred in a sealed flask. The resulting suspension is treated with toluene (15 mL). The precipitated crude product is filtered off and dried in a fine vacuum (3 ^× 10 ^-3 mbar). The

Crude product is taken up in H2O (2 mL) and the solution is added with stirring K2CO3 (1 g). Then acetonitrile (15 mL) is added. This formed a two-phase system (F O / acetonitrile). It will be further

K2CO3 (about 5 g) was added in portions until no more aqueous phase is present. The acetonitrile solution over the solid (mainly

K2CO3) is decanted and concentrated to dryness using a rotary evaporator. The solid obtained is dried in a fine vacuum (3 × 10 ^-3 mbar).

 Yield of K [BF (CN) 3]: 557 mg (3.79 mmol, 83% yield with respect to the Na used [BF4]).

The product is characterized by NMR spectroscopy ( ¹¹ B and ¹⁹ F NMR). The spectra correspond to those from the literature. Example 13. Synthesis of K [BF (CN) ₃ ]

Na [BF ₄ ] (1.0 g, 9.1 mmol) is dissolved in TMSCN (10.0 mL, 74.99 mmol).

taken and the suspension is then treated with TMSCI (1.0 mL, 7.92 mmol, 10.6 mol% based on TMSCN) and stirred overnight at 45 ° C. The voluminous suspension is then treated with TMSOTf (0.1 mL, 0.53 mmol, 0.7 mol% based on TMSCN) and stirred again at 45 ° C for 5 hrs. Then the suspension is treated with toluene (10 mL), the precipitated crude product is filtered off and then dissolved in acetonitrile (15 mL) and the solution is treated with H2O (2 mL). Subsequently, K 2 CO 3 (10 g) is added successively and the acetonitrile phase is removed over the solid and concentrated to dryness in vacuo. The product obtained is dried in a fine vacuum (3 ^× 10 ^-3 mbar).

Yield: 1.30 g (8.84 mmol, corresponding to 97% based on the Na used [BF4], the product contains about 10% isomer

K [BF (CN) 2 (NC)]. The product can be purified with known separation methods. Alternatively, the isomer K [BF (CN) 2 (NC)] can be decomposed by hydrolysis. Hydrolysis of Isocyanoborate, K [BF (CN) ₂ (NC)]

The product containing 10% isomer as described above (1.30 g, 8.84 mmol K [BF (CN) 3]) is dissolved in H 2 O (15 mL) and adjusted to pH 1 with aqueous hydrochloric acid (37%) set. The acidic solution is stirred overnight at RT. Then the solution is made alkaline with KOH and 1-ethyl-3-methylimidazolium chloride (EMIMCI, 1.2 g, 8.21 mmol). The emulsion obtained is extracted with CH 2 Cl 2 (1 × 10, 1 × 5 ml). The organic phases are combined and the CH2Cl2 is in the Vacuum removed. The resulting ionic liquid is dried in a fine vacuum to a final pressure of 3 ^× 10 ³ mbar.

Yield of EMIM [BF (CN) 3]: 1.2 g (5.48 mmol, corresponding to 60%

based on the borate used).

The product is characterized by NMR spectroscopy ( ¹ H, ¹¹ B and ⁹ F NMR).

¹ H-NMR (400.40 MHz, acetone-de), δ, ppm: 9.64 (s, CH, 1 H), 7.82 (dd,

3J (H, ¹ H) « ⁴ J ( ¹ H, ¹ H)« 1.6 Hz, CH, 1H), 7.75 (dd, ³ J ( ¹ H, H) * ⁴ J ( ¹ H, H) «1.7 Hz , CH, 1 H), 4:40 (t, J = 7.40 Hz, CH _2, 2H), 4:06 (s, _CH3, 3H), 1:55 (t, J (H, ¹ H) = 7:37 Hz, Me, 3H ).

Example 14. Synthesis of K [BF (CN) ₃ ]

NaBF _{4 +} 3 (CH ₃ ) ₃ SiCN [BF (CN) ₃ ]

A suspension of Na [BF _4] (1.0 g, 9.1 mmol) in TMSCN (10.0 mL, 74.99 mmol) with trifluoromethanesulfonic anhydride, TF20 (0.1 mL, 12:59 mmol, 0.79 mol% based on TMSCN) was added and the

Reaction mixture then stirred at 40 ° C for 4 hours. Toluene (10 mL) is added to the resulting suspension, the precipitated crude product is filtered off and then dissolved in acetonitrile (10 mL). The solution is treated with H2O (1 mL) and then K2CO3 (10 g) is added.

successively added. The excess solid is removed from the

Filtrated acetonitrile and the organic phase is concentrated in vacuo to dryness. The resulting product is ⁽³ mbar 3 * 10 ^") dried in a fine vacuum.

Yield of K [BF (CN) 3]: 1.30 g (8.84 mmol, corresponding to 97%, based on the Na [BF ₄ ] used). The product is characterized by NMR spectroscopy ( ¹¹ B and ¹⁹ F NMR). The spectra correspond to those from the literature.

Claims

 claims

Process for the preparation of compounds of the formula I

[Me] ⁺ [BF (CN) ₃ ] J-,

 in which

[Me] ⁺ an alkali metal cation means

 by reacting a compound of formula II

[Me] ⁺ [BFn (CN) ₄ -n] - II,

wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

 n is 2, 3 or 4,

 with a trialkylsilyl cyanide in the presence of a trialkylsilyl ester of a perfluoroalkanesulfonic acid, wherein the alkyl groups of the

 Trialkylsilyicyanids and the trialkylsilyl independently of one another denote a linear or branched alkyl group having 1 to 10 C atoms and the perfluoroalkyl group of the sulfonic acid means a linear or branched perfluoroalkyl group having 1 to 4 C atoms,

 wherein the conditions of the reaction are chosen such that the reaction at temperatures of 0 ° C to 50 ° C are performed and that both the water content and the

Oxygen content is at most 1000 ppm, and subsequent metal cation exchange, in case Me ¹ does not correspond to Me.

A method according to claim 1, characterized in that the

Trialkylsilylester the perfluoroalkanesulfonic acid in a total amount of 0.5 to 30 mol% is used, based on the amount of Trialkylsilyicyanids used. 3. The method according to claim 1 or 2, characterized in that the alkyl groups of Trialkylsilyicyanids and the trialkylsilyl ester mean methyl. Method according to one or more of claims 1 to 3, characterized in that the trialkylsilyl ester of

Perfluoroalkanesulfonic acid is formed in situ.

Method according to one or more of claims 1 to 4, characterized in that a compound of formula II is used, in which n is 2 or 4.

Method according to one or more of claims 1 to 5, characterized in that the compound of formula II and the

Trialkylsilylcyanid is first reacted in the presence of trialkyl, Trialkylbrom- and / or Trialkyliodsilan and the reaction

subsequently in the presence of a trialkylsilyl ester

Perfluoroalkanesulfonic acid is completed, wherein the alkyl groups of trialkyl, Trialkylbrom- and / or Trialkyliodsilan each independently a linear or branched alkyl group having 1 to 10 carbon atoms.

Method according to one or more of claims 1 to 6, characterized in that the reaction follows a purification step.

Method according to one or more of claims 1 to 7, characterized in that the metal cation exchange takes place during the purification step.

Method according to one or more of claims 1 to 8, characterized in that the metal cation exchange by reaction with the compound (Me) 2CO3 and / or with the compound MeHCO3, wherein Me corresponds to the alkali metal cation in the compound of formula I.

10. The method according to one or more of claims 1 to 9, characterized in that the reaction of the compound of formula II with trialkylsilyl cyanide takes place in the presence of an organic solvent or without organic solvent.

11. Process for the preparation of compounds of the formula I.

[Me] ⁺ [BF (CN) _3] - I,

 in which

[Me] ⁺ an alkali metal cation means

 by reacting a compound of formula II

[Me] ⁺ [BFn (CN) ₄ -n] - II,

wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

 n is 2, 3 or 4,

 with a trialkylsilyl cyanide in the presence of an alkyl ester of a

Perfluoroalkanesulfonic acid, wherein the alkyl groups of

 Trialkylsilylcyanids each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, the

 Alkyl group of the alkyl ester is methyl or ethyl and the perfluoroalkyl group of the sulfonic acid is a linear or branched

Perfluoroalkyl group having 1 to 4 carbon atoms,

 wherein the conditions of the reaction are chosen such that the reaction at temperatures of 0 ° C to 50 ° C are performed and that both the water content and the

 Oxygen content can be a maximum of 1000 ppm, and then

Metal cation exchange, in case Me ¹ does not correspond to Me.

12. Process for the preparation of compounds of the formula I.

[Me] ⁺ [BF (CN) ₃ ] - I,

 in which

[Me] ⁺ an alkali metal cation means

by reacting a compound of formula II [Me] ⁺ [BFn (CN) ₄ -n] - II, wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

 n is 2, 3 or 4,

 with a trialkylsilyl cyanide in the presence of a

 Perfluoroalkanesulfonic acid, wherein the alkyl groups of

 Trialkylsilylcyanids each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms and the perfluoroalkyl group of sulfonic acid means a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms,

 wherein the conditions of the reaction are chosen such that the reaction at temperatures of 0 ° C to 50 ° C are performed and that both the water content and the

Oxygen content can be at most 1000 ppm, and subsequent metal cation exchange, in the event that Me ¹ does not correspond to Me.

13. Process for the preparation of compounds of the formula I.

[Me] ⁺ [BF (CN) ₃ ] - I,

 in which

[Me] ⁺ an alkali metal cation means

 by reacting a compound of formula II

[Me] ⁺ [BFn (CN) ₄ -n] - II,

wherein Me ^{1 represents} an alkali metal which may be the same or different than Me and

 n is 2, 3 or 4,

 with a trialkylsilyl cyanide in the presence of an anhydride of a perfluoroalkanesulfonic acid, wherein the alkyl groups of the

Trialkylsilylcyanids each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms and the perfluoroalkyl group de sulfonic anhydride means a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms, wherein the conditions of the reaction are chosen such that the reaction at temperatures of 0 ° C to 50 ° C are performed and that both the water content and the

Oxygen content can be at most 1000 ppm, and subsequent metal cation exchange, in the event that Me ¹ does not correspond to Me.