FR3098516A1 - PROCESSES FOR THE PRODUCTION OF TRIS (HALOSULFONYL) METHANE OR ITS SALTS - Google Patents

Abstract

A process for producing tris (halosulfonyl) methane or its salts is provided. The process comprises reacting methanetrisulfonic acid or its salts with an anhydride forming agent under basic or neutral conditions, thereby producing a mixed substituted sulfonic acid anhydride, which can subsequently be reacted. with a halogenating agent to produce tris (halosulfonyl) methane or its salts.

Description

METHODS FOR THE PRODUCTION OF TRIS(HALOSULFONYL)METHANE OR ITS SALTS

The present invention relates to methods of producing methanetrisulfonic acid derivatives. More specifically, the present invention relates to processes for the production of tris(halosulfonyl)methane or its salts.

Certain organic salts of tris(fluorosulfonyl)methane, due to their unique properties, have been proposed as ionic liquids and plastic crystals.

However, there is only one known process for the preparation of such salts, which involves the reaction of extremely dangerous and very expensive SF4 with methanetrisulfonic acid in a pressure vessel. Several inorganic and organic salts of this acid have been prepared. Unfortunately, since SF4 is a very toxic gas, its use is very limited. In fact, it is mostly used only for the production of other fluorinating compounds. Also, its production is linked to dangerous operations and the most limiting factor is its high price, making it suitable for the most part for the preparation of products with a very high added value.

Methanetrisulfonic acid was prepared by the sulfonation of various organic compounds with oleum. However, the best process seems to be the sulfonation of acetic acid derivatives, which has been developed on an industrial scale. The purification of the acid can be obtained by transforming it into a potassium salt, followed by recrystallization. Subsequently, the pure potassium salt can be treated with barium chloride (which is very soluble) to produce barium trimethanesulfonate (which is less soluble than the potassium salt). The methanetrisulfonic acid can then be released with sulfuric acid; however, when using this process, the acid produced contains residual sulfuric acid.

Usually sulfonyl fluorides are prepared by many standard methods as described in many publications and manuals. In addition, several compounds have been prepared by sulfur fluorides. However, it seems that all of these processes fail to produce tris(fluorosulfonyl)methane.

Therefore, it is highly desirable to develop a process for the production of tris(fluorosulfonyl)methane derivatives, which would include less hazardous reagents. It is also desirable that the reactants can be regenerated.

In accordance with the present invention, it is proposed:
1. A process for producing tris(halosulfonyl)methane or a salt thereof, comprising the steps of:
To. obtaining methanetrisulfonic acid or a salt thereof;
b. reacting methanetrisulfonic acid or a salt thereof with an anhydride-forming agent under basic or neutral conditions to produce a mixed anhydride;
vs. halogenating the mixed anhydride to produce tris(halosulfonyl)methane; And
d. optionally, reacting tris(halosulfonyl)methane with a base to produce a tris(halosulfonyl)methane salt,
wherein tris(halosulfonyl)methane is represented by general formula (I):

wherein R1, R2 and R3 each independently represent a halogen atom, and
the tris(halosulfonyl)methane salt has the following formula (II):


in which R1, R2 and R3 are as defined above and CAT+ represents an organic or inorganic cation.
2. The process according to point 1, in which CAT+ represents Li+, Na+, K+, Rb+, Cs+, Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Zn2+ or an organic cation.
3. The process according to one of points 1 or 2, in which for the two formulas (I) and (II), each of R1, R2 and R3 represents F or Cl, more preferably F.
4. The method according to any one of points 1 to 3, in which step a) comprises the steps of:
a1) synthesis of methanetrisulfonic acid and
a2) purification of the methanetrisulfonic acid,
a3) optionally, preparation of the methanetrisulfonic acid salt.
5. The process according to point 4, in which step a1 comprises the sulphonation of an organic compound containing one or more acetyl groups with oleum or another source of SO3, first at a low temperature ( such as below 5°C), then at a higher temperature to obtain a mixture of methanetrisulfonic acid, sulfuric acid, methionic acid and other side products.
6. The process according to one of points 4 or 5, in which step a2) comprises the preparation of a salt of methanetrisulfonic acid and the use of an acid ion exchange resin to produce the acid methanetrisulfonic.
7. The method according to point 6, in which, in step a2):
i. the reaction mixture is neutralized with a base, which causes precipitation of a salt of methanetrisulfonic acid;
ii. recrystallization of the methanetrisulfonic acid salt; And
iii. a solution of the salt is then prepared and passed through an acid ion exchange column to obtain an aqueous solution of methanetrisulfonic acid.
8. The process according to item 7, wherein the base in step i) is a tertiary amine base, preferably pyridine, or preferably a potassium base, such as potassium hydroxide, potassium carbonate or potassium hydrogen carbonate.
9. The process according to one of points 7 or 8, in which, during step ii), the precipitated salt is recrystallized from hot water.
10. The method according to any one of items 7 to 9, wherein the ion exchange is carried out on an aqueous solution.
11. The method according to any one of 7 to 10, wherein the precipitated salt is soluble in organic solvents, and an organic solvent is used during the ion exchange.
12. The process according to any one of items 7 to 11, wherein the ion exchange column used in step ii) is AmberliteTM (eg AmberliteTM IR120) or DowexTM.
13. The process according to any one of points 7 to 12, in which, in step a2), the methanetrisulfonic acid is isolated in the form of its salt, preferably its pyridine salt.
14. The process according to any one of items 4 to 13, wherein, in cases where a salt of methanetrisulfonic acid is desired, and step a2) produces methanetrisulfonic acid, a salt of methanetrisulfonic acid is produced in step a3) by reacting methanetrisulphonic acid with a base.
15. The process according to any one of points 1 to 14, in which, during step b, the methanetrisulfonic acid or the salt thereof is converted into a mixed anhydride of substituted sulfonic acid by reaction with a strong anhydride-forming agent in the presence of an organic base, thus making it possible to produce a mixed anhydride of formula (I) above in which each of R1, R2 and R3 represents a group -O-R4, R4 being a functional group which depends on the nature of the anhydride forming agent used in the reaction, and R4 preferably being a good leaving group, preferably one of the best leaving groups in organic chemistry.
16. The process according to item 15, wherein the anhydride-forming agent is an acylating agent, a sulphonylating agent, a sulfinylating agent, a phosphanylating agent or a phosphorylating agent, preferably a sulphonylating agent.
17. The process according to item 16, wherein R4 represents an acyl group, a sulphinyl group, a sulphonyl group, a sulfanyl group, a phosphanyl group or a phosphoryl group, preferably a sulphonyl group.
18. The process according to point 17, in which the acyl group is a group of formula -C(=O)R5, in which R5 is a functional group which depends on the nature of the acylating agent used in the reaction.
19. The process according to item 18, wherein R5 is halogen, perfluorinated alkyl, perfluorinated aryl or perfluorinated heteroaryl. Preferably, R5 is a halogen atom (preferably F) or a perfluorinated alkyl.
20. The process according to one of points 18 or 19, in which the acylating agent is chosen from: acyl isocyanates, carboxylic halides, carboxylic anhydrides, carbonyl dihalides, oxalyl halides and their mixtures, preferably trifluoroacetyl fluoride (R5 is CF3), trifluoroacetyl chloride (R5 is CF3), carbonyl difluoride (R5 is F), oxalyl fluoride (R5 is F) and mixtures thereof.
21. The process according to point 17, in which the sulfinyl group is a group of the formula -S(=O)-R6, in which R6 is a functional group which depends on the nature of the sulfinylating agent used in the reaction.
22. The process according to point 21, in which R6 is a halogen atom, preferably F.
23. The process according to either of 21 or 22, wherein the sulfinylating agent is thionyl halide, such as thionyl fluoride S(=O)F2 (R6 is F).
24. The process according to point 17, in which the sulphonyl group is a group of formula -S(=O)2-R7, in which R7 is a functional group which depends on the nature of the sulphonylating agent used in the reaction .
25. The process according to item 24, wherein R7 is a halogen atom or a branched or linear, perfluorinated C1-24 alkyl.
26. The process according to one of points 24 or 25, in which the sulphonylating agent is chosen from sulphonic halides, sulphonic anhydrides, sulphonyl isocyanates, inorganic acid fluorides and mixtures thereof.
27. The method according to any one of 24 to 26, wherein the sulfonylating agent is selected from sulfuryl fluoride (R7 is F), sulfuryl chloride fluoride (R7 is F), fluorosulfonyl anhydride (R7 is F), Alkanesulfonyl anhydrides (R7 is F), Alkanesulfonyl halides (R7 is alkyl), Arylsulfonyl anhydrides (R7 is aryl), Arylsulfonyl halides (R7 is aryl), perfluoroalkanesulfonyl anhydrides (R7 is perfluoroalkyl), perfluoroalkanesulfonyl fluorides (R7 is perfluoroalkyl), perfluoroalkanesulfonyl chlorides (R7 is perfluoroalkyl) and mixtures thereof.
28. The process according to any one of 24 to 27, wherein the sulfonylating agent is methane sulfonyl chloride (R7 is F), methane sulfonyl anhydride (R7 is methyl), toluene sulfonyl chloride (R7 is toluene), toluene sulfonyl anhydride (R7 is toluene), triflic anhydride (R7 is CF3), triflic fluoride (R7 is CF3) or triflic chloride (R7 is CF3).
29. The process according to any one of 24 to 28, wherein the sulfonylating agent is triflic anhydride (R7 is CF3).
30. The process according to item 17, wherein the sulfanyl group is a group of the formula -S(R8)3 in which R8 are each a functional group which depends on the nature of the sulfanylating agent used in the reaction.
31. The process according to point 30, in which R8 is a halogen atom, preferably F.
32. The process according to either of 30 or 31, wherein the sulphanilating agent is a sulfur tetrahalide, such as sulfur tetrafluoride (R8 is F).
33. The process according to point 17, in which the phosphanyl group is a group of formula -OP-(R9)n, in which n is 2 or 4 and in which R9 is a functional group which depends on the nature of the phosphanylating agent used in the reaction.
34. The process according to point 33, in which R9 is a halogen atom, preferably F.
35. The process according to one of points 33 or 34, in which the phosphanylating agent is chosen from phosphorus pentahalides, such as phosphorus pentafluoride PF5 (n is 4 and R9 is F), and phosphorus trihalides , such as phosphorus trifluoride PF3 and phosphorus trichloride (n is 2 and R9 is F or Cl), and mixtures thereof.
36. The process according to point 17, in which the phosphoryl group is a group of formula -P(=O)-(R10)2, in which the R10 are each a functional group which depends on the nature of the phosphorylating agent used in the reaction.
37. The process according to point 36, in which R10 is a halogen atom, preferably F.
38. The method of either 36 or 37, wherein the phosphorylating agent is a phosphoryl halide, such as phosphoryl fluoride P(=O)F3 (R10 is F).
39. The process according to any one of items 15 to 38, wherein the reaction of step b is carried out in the presence of an unreactive organic solvent or without dilution, i.e. without the use of a solvent, for example in cases where the anhydride-forming agent is liquid and is used in excess.
40. The process according to any one of 15 to 39, wherein an organic salt of methanetrisulfonic acid is used in step b).
41. The process according to point 40, in which the organic salt of methanetrisulfonic acid has been prepared using tertiary amines.
42. The process according to any one of items 15 to 41, wherein the reaction of step b takes place under basic conditions.
43. The process according to any one of items 15 to 42, wherein an organic base catalyst which promotes the reaction of step b is added, for example pyridine derivatives such as dimethylaminopyridine, pyrrolidinopyridine and guanidinopyridines; imidazole derivatives; triphenylphosphine oxide; guanidine; tripropylamine; and amidine bases.
44. The process according to item 43, wherein the organic base catalyst is dimethylaminopyridine, pyrolidinopyridine, tripropylamine or a mixture thereof.
45. The process according to any of 15 to 44, wherein a pressure vessel is used during step b.
46. The process according to any one of items 15 to 45, wherein reaction step b is carried out by mixing the methanetrisulfonic acid or its salt with the anhydride-forming agent for as long as necessary to produce the mixed anhydride.
47. The process according to any of items 15 to 46, wherein the mixing takes between about 5 hours and about 6 days, more preferably between about 16 hours and about 5 days.
48. The process according to any one of 1 to 47, wherein during step c the mixed anhydride is reacted with a halogenating agent to produce tris(halosulfonyl)methane.
49. The process according to item 48, wherein the tris(halosulfonyl)methane is tris(fluorosulfonyl)methane (i.e. a compound of formula (I) wherein each of R1, R2 and R3 represents a fluorine atom).
50. The method according to either of 48 or 49, wherein the halogenating agent is a fluorinating agent.
51. The process according to point 50, in which the fluorinating agent is chosen from hydrogen fluoride and its salts, preferably ammonium, substituted ammonium, lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, antimony and arsenic; aluminum fluorides, potassium fluorides (such as KF and KH2F), and potassium hydrogen difluorides (such as KF and KHF2); complex inorganic and organic fluorides such as hexafluorophosphates, hexafluorosilicates, hexafluoroaluminates and tetrafluoroborates; polyhydrogen fluorides; complex salts of amines with hydrofluoric acid, such as pyridinium and triethylammonium polyhydrogen fluorides, and liquid complexes of organic amines with hydrogen fluoride, such as: Et3N×xHF (preferably Et3N×3HF), Pyr×xHF; reactive inorganic and organic acid fluorides, such as PF5, POF3, SOF2, FSO3H, COF2 and FCOCOF, organic and inorganic; sulfur tetrafluoride and its organic derivatives, such as DAST, diethylaminosulfur trifluoride and morpholinosulfur trifluoride; cyanuric fluoride, acetyl fluoride; benzoyl fluoride; trifluoroacetyl fluoride; methanesulfonyl fluoride; triflic fluoride; benzoyl fluoride; benzenesulfonyl fluoride; toluenesulfonyl fluoride; and their mixtures.
52. The process according to one of points 50 or 51, in which the fluorinating agent is chosen from complex salts of amines with hydrofluoric acid, complex inorganic and organic fluorides and polyhydrofluorides.
53. The process according to any one of items 50 to 52, wherein the fluorinating agent is a liquid complex of organic amines with hydrogen fluoride, such as: Et3N×xHF (preferably Et3N×3HF) and Pyr×xHF.
54. The method according to any of 50 to 53, wherein the fluorinating agent is Et3N×3HF in which KHF2 is optionally suspended.
55. The process according to any one of 48 to 54, wherein the mixed anhydride is halogenated by mixing it with the halogenating agent for a period of time as long as necessary to halogenate the mixed anhydride .
56. The process according to item 55, wherein the mixing takes between about 2 hours and about 20 days, more preferably between about 4 hours and about 16 hours.
57. The method according to any one of items 1 to 56, wherein optional step d is performed.
58. The process according to point 57, in which, during step d, the halogenated derivative is isolated in the form of a free acid or in the form of an organic or inorganic salt.
59. The process according to point 58, in which the tris(halosulfonyl)methane is a strongly acidic compound (for example, tris(fluorosulfonyl)methane), which is neutralized during step d by an inorganic or organic base to produce the organic or inorganic salt.
60. The process according to point 59, in which the reaction mixture obtained after halogenation is neutralized or made slightly alkaline to ensure that all the acids are in their anionic form, after which the separation of anions is carried out by the addition of the organic base, which results in the precipitation of a hydrophobic organic salt comprising an organic cation originating from the organic base and a hydrophobic anion originating from the tris(halosulfonyl)methane.
61. The process according to point 60, in which the hydrophobic organic salt is then isolated by filtration or by extraction with an organic solvent immiscible with water.
62. The process according to any one of points 59 to 61, in which the organic base is chosen from monoalkylammonium, dialkylammonium, trialkylammonium, tetraalkylammonium salts (preferably tetrabutylammonium bromide), tetraalkylphosphonium salts and their mixtures.
63. The process according to any one of 59 to 62, wherein a resin-immobilized quaternary ammonium salt - anion exchange resin is used.
64. The process according to any one of items 59 to 63, wherein the tris(halosulfonyl)methane is isolated as a hydrophobic organic salt.
65. The process according to item 64, wherein the hydrophobic organic salt is in the form of a tris(halosulfonyl)methide.
66. The method of item 65, wherein the hydrophobic organic salt further comprises an organic salt of the anhydride-forming agent anion.
67. The process according to either of 64 or 65, wherein tetrabutylammonium bromide is used as the organic base, and the resulting hydrophobic organic salt comprises tetrabutylammonium tris(halosulfonyl)methide, preferably tris(fluorosulfonyl)methide of tetrabutylammonium.
68. The process according to item 67, wherein the hydrophobic organic salt further comprises tetrabutyl ammonium triflate.
69. The process according to any of items 64 to 68, wherein the hydrophobic organic salt is further reacted with a suitable metal base to produce an inorganic salt.
70. The process according to point 69, in which the metal base is chosen from alkali and alkaline earth metal hydroxides, alkoxides, substituted amides, alkyl metals and Grignard reagents.
71. The process according to either of 69 or 70, in which the hydrophobic organic salt is mixed with a solution of at least 1 equivalent of the metallic base, preferably an alkaline or alkaline-earth base, more preferably LiOH, NaOH, KOH, RbOH, CsOH, Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Al(OH)3, Zn(OH) 2 or an alkoxide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al or Zn.
72. The process according to any one of items 58 to 71, wherein the organic or inorganic salt is purified using crystallization and any suitable selective extraction process.
73. The process according to any one of items 64 to 68, in which the hydrophobic organic salt is dissolved in cold concentrated sulfuric acid, then the volatile compounds, removed by distillation at reduced pressure, after which the distillate is directly fractionated to obtain the pure acid.
74. The process according to item 73, wherein a hydrophobic organic salt comprises not only the hydrophobic organic salt tris(halosulfonyl)methide, but also a hydrophobic organic salt comprising the anion of the anhydride-forming agent (preferably triflate anions), such that tris(halosulfonyl)methane is a product, while an acid of the anhydride forming agent (preferably triflic acid) is a side product of the above product .
75. The process according to item 74, wherein the acid of the anhydride-forming agent (preferably triflic acid) is then converted into an anhydride (preferably triflic anhydride).
76. The process for purifying crude methanetrisulfonic acid, comprising the steps of:
To. neutralizing the crude methanetrisulfonic acid with a base, causing precipitation of a methanetrisulfonic acid salt;
b. recrystallize the methanetrisulfonic acid salt; And
vs. passing a solution of the recrystallized salt through an acid ion exchange column to obtain an aqueous solution of purified methanetrisulfonic acid.
77. The method according to item 76, wherein the method is as defined in step a2 in accordance with any of items 4 to 13.
78. The method of either 76 or 77, wherein the method further comprises the step of synthesizing methanetrisulfonic acid to produce the methanetrisulfonic acid mixture.
79. The process according to any of items 76 to 78, wherein the process further comprises the step of preparing a salt of methanetrisulfonic acid with the purified methanetrisulfonic acid.

In a first aspect of the invention, there is provided a process for the production of tris(halosulfonyl)methane or its salts.

The present inventors have discovered that methanetrisulfonic acid or its salts can be converted into a reactive mixed anhydride by reacting methanetrisulfonic acid with a strong anhydride-forming agent under basic or neutral conditions; the inventors have also discovered that the reactive mixed anhydride can then be halogenated to form a halogenated derivative of methanetrisulfonic acid.
The process for the production of tris(halosulfonyl)methane or its salts

1. se procurer de l’acide méthanetrisulfonique ou un sel de celui-ci ;
2. faire réagir l’acide méthanetrisulfonique ou le sel de celui-ci avec un agent de formation d’anhydride dans des conditions basiques ou neutres pour produire un anhydride mixte ;
3. halogéner l’anhydride mixte pour produire du tris(halosulfonyl)méthane ; et
4. facultativement, faire réagir le tris(halosulfonyl)méthane avec une base pour produire un sel du tris(halosulfonyl)méthane.

Tris(halosulfonyl)méthane ou ses selsIn a first aspect of the invention, a process for the production of tris(halosulfonyl)methane or a salt thereof is provided. The method of the present invention comprises the steps of:

1. obtaining methanetrisulfonic acid or a salt thereof;
2. reacting methanetrisulfonic acid or the salt thereof with an anhydride-forming agent under basic or neutral conditions to produce a mixed anhydride;
3. halogenating the mixed anhydride to produce tris(halosulfonyl)methane; And
4. optionally, reacting the tris(halosulfonyl)methane with a base to produce a tris(halosulfonyl)methane salt.

Tris(halosulfonyl)methane or its salts

The tris(halosulfonyl)methane produced by the process of the invention can be represented by the general formula (I):

in which R ¹ , R ² and R ³ each independently represent a halogen atom.

For greater clarity, the tris(halosulfonyl)methane salts produced by the process of the invention have the following formula (II):

in which R ¹ , R ² and R ³ are as defined above and CAT ⁺ represents an organic or inorganic cation.

Such salts may be referred to as tris(halosulfonyl)methide salts.

In preferred embodiments, CAT ⁺ represents Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Al ³⁺ , Zn ²⁺ or an organic cation. It goes without saying that those skilled in the art will understand that when the cation and the anion of the salt have different valences, they will be present in different numbers to balance the electrical charge of the compound (for example two anions such as above with a divalent cation).

In preferred embodiments of both formulas (I) and (II), each of R ¹ , R ² and R ³ represents F or Cl, more preferably F.
Step a) Obtain methanetrisulfonic acid or a salt thereof

As noted above, the first step is to procure methanetrisulfonic acid or a salt thereof. Methanetrisulphonic acid is of the formula (III):

As can be seen, the methanetrisulfonic acid of formula (III) is structurally similar to general formula (I), except that R ¹ , R ² and R ³ each independently represent OH instead of a halogen atom .

Similarly, the methanetrisulfonic acid salts are also of the formula (I) above, in which R ¹ , R ² and R ³ each independently represent O-(cat)+, where (cat)+ represents a cation organic or inorganic.

The methanetrisulfonic acid or salt thereof can be provided using any method known in the art.

In embodiments, step a) comprises the steps of:
a1) synthesize methanetrisulfonic acid and
a2) purifying the methanetrisulfonic acid,
a3) optionally, prepare the methanetrisulfonic acid salt.
Step a1)

Those skilled in the art would understand that apart from the preferred methods described below, methanetrisulfonic acid can be obtained using a variety of methods and steps.

One method of synthesizing methanetrisulfonic acid is described in US 2,333,701, incorporated herein by reference. In a few words, this process comprises the sulphonation of an organic compound containing one or more acetyl groups with oleum or another source of SO ₃ , first at a low temperature (such as below 5 °C), then at higher temperatures so as to obtain a mixture of methanetrisulfonic acid, sulfuric acid, methionic acid and other secondary products.

In preferred embodiments, the organic compound containing the acetyl group is acetic acid, acetic anhydride or acetone.

The organic compound containing the acetyl group can be added to the mixture containing the source of SO ₃ (eg oleum) and be heated gradually in stages or all at once. For example, half of the organic compound containing the acetyl group (eg acetic anhydride) can be added to the oleum and the temperature then gradually raised to 75°C. The other half of organic compound can then be added, and the temperature raised to 95°C. As another example, the organic compound containing the acetyl group (eg acetone) can be added entirely to the oleum, and the mixture can be gradually heated to 75°C.

Sources of SO ₃ could be any chemical compound which generates sulfur trioxide under the reaction conditions used. In some embodiments, these compounds are chosen from the following reagents: SO ₃ (sulfur trioxide itself), comprising its oligomers and polymers; H ₂ SO ₄ (sulphuric acid); H ₂ S ₂ O ₇ (disulfuric acid), as well as other polysulfuric acids and their salts; ClSO ₃ H (chlorosulfonic acid) and its salts; FSO ₃ H (fluorosulfonic acid) and its salts; an SO ₃ -ammonia complex, such as sulfamic acid; sulfur trioxide complexes with organic amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N-alkyl substituted pyrrolidines, morpholines, pyridine, picoline, lutidine, quinoline, N,N -dimethylaniline and other amines; sulfur trioxide complexes with other organic compounds such as dioxane, thioxane and dimethylformamide; and acyl sulphates which are generated by the introduction of SO ₃ into dry carboxylic acids, for example acetyl sulphate (CH ₃ COOSO ₃ H).
Step a2)

The next step is the separation of impurities from the desired methanetrisulfonic acid.

In preferred embodiments, step a2) comprises the preparation of a methanetrisulfonic acid salt and the use of an acidic ion exchange resin to produce the methanetrisulfonic acid.

1. le mélange réactionnel est neutralisé par une base, ce qui provoque une précipitation d’un sel d’acide méthanetrisulfonique ;
2. recristallisation du sel d’acide méthanetrisulfonique ; et
3. une solution du sel est ensuite préparée et amenée à passer à travers une colonne échangeuse d’ions acide pour obtenir une solution aqueuse d’acide méthanetrisulfonique.

In more preferred embodiments, in step a2):

1. the reaction mixture is neutralized with a base, which causes precipitation of a methanetrisulfonic acid salt;
2. recrystallization of the methanetrisulfonic acid salt; And
3. a solution of the salt is then prepared and passed through an acid ion exchange column to obtain an aqueous solution of methanetrisulfonic acid.

• une base amine tertiaire, telle que celles décrites en regard de l’étape a3) ci-dessous, de préférence la pyridine, ou
• de préférence une base potassique, telle que l’hydroxyde de potassium, le carbonate de potassium ou l’hydrogéno carbonate de potassium, qui provoquent une précipitation d’un sel tripotassique d’acide méthanetrisulfonique en tant que monohydrate.

The base used in step i) can be any base which will cause the precipitation of a methanetrisulfonic acid salt. In embodiments, the basis for step i) is:

• a tertiary amine base, such as those described with regard to step a3) below, preferably pyridine, or
• preferably a potassium base, such as potassium hydroxide, potassium carbonate or potassium hydrogen carbonate, which causes precipitation of a tripotassium salt of methanetrisulfonic acid as monohydrate.

During step ii), the precipitated salt is recrystallized. If the above tripotassium salt is used, it is preferably recrystallized from hot water to produce a high purity potassium salt of methanetrisulfonic acid in the form of colorless needles.

For the ion exchange column used in step iii) a number of commercially available resins could be used such as Amberlite ^TM (eg Amberlite ^TM IR120) and Dowex ^TM ; however, the ion exchange resin should be strongly acidic.

If the above tripotassium salt is used, ion exchange is most conveniently performed on an aqueous solution since the solubility of potassium methanetrisulfonate is negligible in organic solvents. However, if other salts of methanetrisulfonic acid are used and their solubility is satisfactory in organic solvents, these solvents can also be used.

In other embodiments of step a2), the methanetrisulfonic acid can be isolated in the form of its salt. This could be done by any known isolation methods, for example, recrystallization, extraction, or any other isolation method known in the art.

For example, the reaction mixture originating from the sulphonation reaction (namely the addition of SO ₃ groups) of step a1) can be diluted with water and neutralized with an excess of a base. In preferred embodiments, the base is a tertiary amine base, such as those described below with regard to step a3), preferably pyridine, or a potassium base, such as potassium hydroxide, potassium carbonate or potassium hydrogen carbonate. After evaporation and drying in a vacuum, the waxy solid can be extracted several times with acetonitrile containing isopropanol. A white solid remains, which is composed mostly of tripyridinium methanetrisulfonate (if pyridine is used as the base); in extracts, mostly pyridinium salts of other acids can be identified.
Step a3)

It will appear clearly on reading the description above that, in certain embodiments, step a2) leads to methanetrisulphonic acid, whereas, in other embodiments, it leads to a salt of methanetrisulfonic acid.

In cases where a methanetrisulphonic acid salt is desired, and step a2) produces methanetrisulphonic acid, a methanetrisulphonic acid salt can be obtained in step a3) by reacting methanetrisulphonic acid with a base as is well known in the art.

As previously mentioned, the methanetrisulfonic acid salts can be represented by the general formula above (I), in which R ¹ , R ² and R ³ each independently represent O-(cat)+, where (cat)+ represents an organic or inorganic cation.

For example, salts of methanetrisulfonic acid could be obtained by the neutralization of free methanetrisulfonic acid with a base, preferably an organic base, which yields an organic salt where (cat)+ represents an organic cation.

Of course, in preferred embodiments, an organic salt of methanetrisulfonic acid is provided. In even more preferred embodiments, said organic salt of methanetrisulfonic acid is prepared with a tertiary amine base, since such bases are widely available and can be easily recycled. The term "tertiary amines" refers to any amines having all three nitrogen valencies occupied by organic substituents. For example, tertiary amines include the following: trimethylamine, triethylamine, tripropylamine, tributylamine, N-alkyl substituted pyrrolidines, morpholines, N -methylimidazole, pyridine, picoline, lutidine, quinoline, N,N- dimethylaniline, ethyldiisopropylamine, quinuclidine, DBU ( 1,8-diazabicyclo(5.4.0)undec-7-ene), DBN (1,5-diazabicyclo[4.3.0]non-5-ene), 4-dimethylaminopyridine and 4-pyrrolidinopyridine. In preferred embodiments, the tertiary amine is triethyl amine, resulting in the production of triethylammonium methanetrisulfonate.

To produce the inorganic salts, the organic salts, preferably tertiary ammonium salts, of methanetrisulfonic acid can be reacted with metal bases so as to substitute the tertiary ammonium group with a metal cation.
Step b) Reaction of methanetrisulfonic acid or a salt thereof

As noted above, step b) involves reacting methanetrisulfonic acid or a salt thereof with an anhydride-forming agent under basic or neutral conditions to produce a reactive mixed anhydride.

In this step, the methanetrisulfonic acid or salt thereof is converted into a mixed substituted sulfonic acid anhydride by reaction with an anhydride-forming agent in the presence of an organic base. This reaction replaces the H on each of the OH groups attached to the S atoms of the methanetrisulfonic acid or salt thereof with -R ⁴ groups. This produces a mixed anhydride of formula (I) above, wherein each of R ¹ , R ² , and R ³ represents an -OR ⁴ group.

In the group of formula -OR ⁴ , R ⁴ is a functional group which depends on the nature of the anhydride-forming agent used in the reaction. It is preferred that the —OR ⁴ group introduced represent a good leaving group, preferably one of the best leaving groups in organic chemistry, all of which are well known to those skilled in the art.

In embodiments, in the group -OR ⁴ , R ⁴ represents an acyl group, a sulfynyl group, a sulfonyl group, a sulfanyl group, a phosphanyl group or a phosphoryl group.

Preferably, R ⁴ represents a sulphonyl group.

Thus, in embodiments, the anhydride-forming agent is an acylating agent, sulfonylating agent, sulfinylating agent, phosphanylating agent, or phosphorylating agent. Preferably the anhydride forming agent is a sulfonylating agent.
acylating agent; R ⁴ = Acyl Group

An acyl group is a group of formula -C(=O)R ⁵ , in which R ⁵ is a functional group which depends on the nature of the acylating agent used in the reaction.

In embodiments, R ⁵ is halogen, perfluorinated alkyl, perfluorinated aryl or perfluorinated heteroaryl. Preferably, R ⁵ is a halogen atom (preferably F) or a perfluorinated alkyl.

• les isocyanates d’acyle (à savoir les composés de formule R⁵-C(=O)-N=C=O) ;
• les halogénures carboxyliques (à savoir les composés de formule R⁵-C(=O)-halogène) ;
• les anhydrides carboxyliques (à savoir les composés de formule R⁵-C(=O)-O-C(=O)-R⁵) ;
• les dihalogénures de carbonyle (à savoir les composés de formule C(=O)-halogène₂) , ou
• les halogénures d’oxalyle, (à savoir les composés de formule halogène-C(=O)-C(=O)-halogène) ;

et leurs mélanges, et autres composés qui peuvent être choisis par l’homme du métier.In embodiments, the acylating agent is chosen from:

• acyl isocyanates (namely the compounds of formula R ⁵ -C(=O)-N=C=O);
• carboxylic halides (namely compounds of formula R ⁵ -C(=O)-halogen);
• carboxylic anhydrides (namely the compounds of formula R ⁵ -C(=O)-OC(=O)-R ⁵ );
• carbonyl dihalides (i.e. compounds of the formula C(=O)-halogen ₂ ), or
• oxalyl halides, (namely compounds of the formula halogen-C(=O)-C(=O)-halogen);

and mixtures thereof, and other compounds which may be chosen by those skilled in the art.

In preferred embodiments, the acylating agent is chosen from trifluoroacetyl fluoride (R ⁵ represents CF ₃ ), trifluoroacetyl chloride (R ⁵ is CF ₃ ), carbonyl difluoride (R ⁵ is F), oxalyl fluoride (R ⁵ is F), mixtures thereof, and other compounds which can be chosen by those skilled in the art.
Sulfinylating agent; R4 = Sulfinyl Group

A sulfinyl group is a group of formula -S(=O)-R ⁶ , in which R ⁶ is a functional group which depends on the nature of the sulfinylating agent used in the reaction.

In preferred embodiments, R ⁶ is a halogen atom, preferably F.

In embodiments, the sulfinylating agent is a thionyl halide, such as thionyl fluoride S(=O)F ₂ (R ⁶ is F), and other compounds which can be chosen by those skilled in the art.
Sulfonylating agent; R ⁴ = Sulfonyl Group

A sulphonyl group is a group of formula -S(=O) ₂ -R ⁷ , in which R ⁷ is a functional group which depends on the nature of the sulphonylating agent used in the reaction.

In preferred embodiments, R ⁷ is a halogen atom or a branched or linear, perfluorinated C _1-24 alkyl.

In embodiments, the sulphonylating agent is chosen from sulphonic halides, sulphonic anhydrides, sulphonyl isocyanates, inorganic acid fluorides, and mixtures thereof.

In preferred embodiments, the sulfonylating agent is selected from sulfuryl fluoride (R ⁷ is F), sulfuryl fluoride chloride (R ⁷ is F), fluorosulfonyl anhydride (R ⁷ is F), alkanesulfonyl anhydrides (R ⁷ is alkyl), alkanesulfonyl halides (R ⁷ is alkyl), arylsulfonyl anhydrides (R ⁷ is aryl), arylsulfonyl halides (R ⁷ is aryl), perfluoroalkanesulfonyl (R ⁷ is perfluoroalkyl), perfluoroalkanesulfonyl fluorides (R ⁷ is perfluoroalkyl), perfluoroalkanesulfonyl chlorides (R ⁷ is perfluoroalkyl), their mixtures and other compounds which can be chosen by those skilled in the art.

In more preferred embodiments, the sulfonylating agent is methane sulfonyl chloride (R ⁷ is methyl), methane sulfonyl anhydride (R ⁷ is methyl), toluene sulfonyl chloride (R ⁷ is 4-tolyl , 4-methylphenyl), toluene sulfonyl anhydride (R ⁷ is 4-tolyl, 4-methylphenyl), triflic anhydride (R ⁷ is CF ₃ ), triflic fluoride (R ⁷ is CF ₃ ) or chloride triflic (R ⁷ is CF ₃ ). In a more preferred embodiment, the sulfonylating agent is triflic anhydride (R ⁷ is CF ₃ ).
Sulphanylating agent; R ⁴ = Sulfanyl Group

A sulfanyl group is a group of formula -S(R ⁸ ) ₃ , in which the R ⁸ are each a functional group which depends on the nature of the sulphanylating agent used in the reaction.

In preferred embodiments, R ⁸ is a halogen atom, preferably F.

In preferred embodiments, the sulphanylating agent is a sulfur tetrahalide, such as sulfur tetrafluoride (R ⁸ is F).
Phosphanylating agent; R ⁴ = Phosphanyl group

A phosphanyl group is a group of formula -OP-(R ⁹ ) _n , in which n is 2 or 4 and in which R ⁹ is a functional group which depends on the nature of the phosphanylating agent used in the reaction.

In embodiments, R ⁹ is a halogen atom, preferably F.

In embodiments, n is 2. In other embodiments, n is 4.

In embodiments, the phosphanylating agent is chosen from phosphorus pentahalides, such as phosphorus pentafluoride PF ₅ (n is 4 and R ⁹ is F), and phosphorus trihalides, such as phosphorus trifluoride PF ₃ and phosphorus trichloride (n is 2 and R ⁹ is F or Cl), their mixtures, and other compounds which can be chosen by those skilled in the art.
Phosphorylating agent; R ⁴ = Phosphoryl group

A phosphoryl group is a group of formula -P(=O)-(R ¹⁰ ) ₂ , in which the R ¹⁰ are each a functional group which depends on the nature of the phosphorylating agent used in the reaction.

In embodiments, R ¹⁰ is a halogen atom, preferably F.

In some embodiments, the phosphorylating agent is a phosphoryl halide, such as phosphoryl fluoride P(=O)F ₃ (R ¹⁰ is F) or other compounds which can be chosen by those skilled in the art.
Reaction conditions

In embodiments, the reaction is carried out in the presence of an unreactive organic solvent or without dilution, i.e. without using a solvent, for example in cases where the anhydride-forming agent is liquid and is used in excess.

In preferred embodiments, and as previously mentioned, an organic salt of methanetrisulfonic acid is used in this step of the process since such salts tend to be soluble in organic solvents, unlike most inorganic salts of methanetrisulfonic acid. As also mentioned, in a more preferred embodiment, tertiary amines are used for the preparation of said organic salts of methanetrisulfonic acid since they are widely available and can be easily recycled.

As mentioned, the reaction takes place under basic or neutral conditions. In preferred embodiments, the reaction takes place under basic conditions. In more preferred embodiments, an organic base catalyst which promotes the reaction is added, for example pyridine derivatives such as dimethylaminopyridine, pyrrolidinopyridine and guanidinopyridines; imidazole derivatives; triphenylphosphine oxide; guanidine; tripropylamine; and amidine bases. In a more preferred embodiment, dimethylaminopyridine, pyrrolidinopyridine, tripropylamine or a mixture thereof is added as a catalyst.

The reaction temperature can be anywhere from about -50°C up to 300°C, depending on the reagents used. In some cases, the use of a pressure vessel might be necessary, especially if the anhydride-forming agent has a low boiling point.

In embodiments, the reaction is carried out by mixing the methanetrisulfonic acid or its salt with the anhydride-forming agent for as long as necessary to produce the mixed anhydride. In preferred embodiments, mixing takes place between about 5 hours and about 6 days, more preferably between about 16 hours and about 5 days.
Step c) Halogenation of the mixed anhydride

To halogenate the mixed anhydride defined in the previous section, the mixed anhydride is reacted with a halogenating agent, which acts as a source of halogen ions. Halogen ions displace leaving groups (e.g. acyloxy groups or sulfonyloxy groups) in the molecule, leaving a halogen atom attached to each S atom. This produces tris(halosulfonyl)methane.

In a preferred embodiment, the (halosulfonyl)methane is tris(fluorosulfonyl)methane (namely a compound of formula (I) in which each of R ¹ , R ² and R ³ represents a fluorine atom). This compound can be obtained by using a fluorinating agent as a halogenating agent.

Thus, in preferred embodiments, the halogenating agent is a fluorinating agent.

In more preferred embodiments, the fluorinating agent is chosen from hydrogen fluoride and its salts, in particular fluorides and hydrogen difluorides of ammonium, substituted ammonium, lithium, sodium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, antimony, arsenic, aluminum and potassium (such as KF and KHF ₂ ); complex inorganic and organic fluorides such as hexafluorophosphates, hexafluorosilicates, hexafluoroaluminates and tetrafluoroborates; polyhydrogen fluorides; complex salts of amines with hydrofluoric acid, such as pyridinium and triethylammonium polyhydrofluorides, and liquid complexes of organic amines with hydrogen fluoride, such as: Et ₃ N×xHF (preferably Et ₃ N ×3HF), Pyr×xHF; reactive inorganic and organic acid fluorides, such as PF ₅ , POF ₃ , SOF ₂ , FSO ₃ H, COF ₂ and FCOCOF, organic and inorganic; sulfur tetrafluoride and its organic derivatives, such as DAST, diethylaminosulfur trifluoride and morpholinosulfur trifluoride; cyanuric fluoride, acetyl fluoride; benzoyl fluoride; trifluoroacetyl fluoride; methanesulfonyl fluoride; triflic fluoride; benzoyl fluoride; benzenesulfonyl fluoride; toluenesulfonyl fluoride; mixtures thereof; and other compounds which may be selected by those skilled in the art.

In even more preferred embodiments, the fluorinating agent is chosen from complex salts of amines with hydrofluoric acid, complex inorganic and organic fluorides and polyhydrogen fluorides.

In an even more preferred embodiment, the fluorinating agent is a liquid complex of organic amines with hydrogen fluoride, such as: Et ₃ N×xHF (preferably Et ₃ N×3HF) and Pyr×xHF, given that they are relatively cheap and readily available. In a most preferred embodiment, the fluorinating agent is Et ₃ N×3HF in which KHF ₂ is optionally suspended.

In embodiments, the mixed anhydride is halogenated by mixing it with the halogenating agent for as long as necessary to halogenate the mixed anhydride. In preferred embodiments, mixing takes between about 2 hours and about 20 days, more preferably between about 4 hours and about 16 hours.
Optional step d) Isolation of tris(halosulfonyl)methane

Optionally, the process of the present invention further comprises a step of isolating the tris(halosulfonyl)methane produced in step c).

Isolation of tris(halosulfonyl)methane can be done in several ways, for example the halogen derivative can be isolated as a free acid or as an organic or inorganic salt. This can be done using methods known in the art. Typically, tris(halosulfonyl)methane is a strongly acidic compound (eg, tris(fluorosulfonyl)methane), which can be neutralized with an inorganic or organic base to produce an organic or inorganic salt. Conversion of an acid to its salt is a standard procedure for neutralization with an organic base or an appropriate metal content.
Step d1) Isolation of tris(halosulfonyl)methane as organic salt

If an organic salt is desired, the reaction mixture obtained after halogenation can be neutralized or made slightly alkaline to ensure that all the acids are in their anionic form. Then, the separation of anions can be carried out by the addition of an organic base, which results in the precipitation of a hydrophobic organic salt comprising the organic cation from the organic base and a hydrophobic anion from the tris(halosulfonyl )methane. Conversely, small inorganic anions such as fluoride, chloride and sulfate remain in the aqueous phase.

However, if the anhydride-forming agent used during step b) above also has a hydrophobic anion, then the anion of the anhydride-forming agent (preferably triflate anions), which is formed during the halogenation step and remains in the reaction mixture, is also hydrophobic, which means that it can also be extracted as a hydrophobic organic salt. Therefore, a mixture of hydrophobic organic salts can be obtained. As will be seen below, this is not necessarily disadvantageous since it allows recycling and reuse of the anhydride-forming agent.

In any case, the resulting hydrophobic organic salt (or mixture of hydrophobic organic salts) can then be isolated by filtration, or by extraction with an organic solvent immiscible with water.

The organic base can be chosen from monoalkylammonium, dialkylammonium, trialkylammonium, tetraalkylammonium (preferably tetrabutylammonium bromide), tetraalkylphosphonium salts and mixtures thereof.

It would be understood by those skilled in the art that a resin immobilized quaternary ammonium salt – anion exchange resin could also be used for this purpose.

When tris(halosulfonyl)methane is isolated as a hydrophobic organic salt, it is typically in the form of a tris(halosulfonyl)methide (see formula II above). For example, and preferably, if the tris(halosulfonyl)methane is tris(fluorosulfonyl)methane then tetrabutylammonium bromide is used as the organic base, the resulting hydrophobic organic salt is tetrabutylammonium tris(fluorosulfonyl)methide. If, for example, triflic anhydride is used as an anhydride-forming agent, the hydrophobic organic salt will also contain tetrabutyl ammonium triflate.
Step d2) Isolation of tris(halosulfonyl)methane as an inorganic salt

If an inorganic salt (e.g. tris(fluorosulfonyl)methane) is desired, the hydrophobic organic salt obtained in the previous step d1) can serve as the starting compound. Of course, these hydrophobic salts can be easily converted into metallic salts by reaction with a suitable metallic base. The metal bases can be chosen from alkali and alkaline-earth metal hydroxides, alkoxides, substituted amides, alkyl metals and Grignard reagents, all of which are particularly strong bases.

In a most preferred embodiment, the hydrophobic organic salt is mixed with a solution of at least 1 equivalent of the metal base, preferably an alkaline or alkaline earth base, more preferably LiOH, NaOH , KOH, RbOH, CsOH, Be(OH) ₂ , Mg(OH) ₂ , Ca(OH) ₂ , Sr(OH) ₂ , Ba(OH) ₂ , Al(OH) ₃ , Zn(OH) ₂ or a alkoxide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al or Zn.

To produce the inorganic salt, the appropriate metal base and the hydrophobic organic salt can be mixed and diluted with an appropriate non-reactive solvent. In embodiments, the solvent is selected from water or lower aliphatic alcohols such as methanol, ethanol, isopropanol, propanol and butanol. It is preferred to use an amount of solvent just sufficient to dissolve the reactive compounds.

The mixture can then be heated between 30°C and 300°C if necessary. The reaction is rapid and typically takes less than 24 hours, in most cases less than 12 hours, and in special cases less than 1 hour.

In some cases, the inorganic salt produced crystallizes from the reaction mixture upon cooling. In other cases, the mixture is evaporated to remove volatile compounds and the product is solvent extracted and recrystallized to its pure form.

For both organic salts and inorganic salts, salt purification can also be accomplished by crystallization and any suitable selective extraction methods. For example, when an organic salt has been obtained by adding an organic cationic compound, the resulting mixture can be extracted with ethyl acetate and dichloromethane, and the combined organic phases can be dried with anhydrous MgSO ₄ and evaporated.
Step d2') Isolation of tris(halosulfonyl)methane in the form of the free acid

Another way to isolate tris(halosulfonyl)methane, preferably tris(fluorosulfonyl)methane, is to convert a salt thereof to the free acid form, which is volatile and can be isolated by distillation or sublimation directly.

For example, the hydrophobic organic salt obtained in the previous step d1) can be dissolved in cold concentrated sulfuric acid, then the volatile compounds, removed by distillation at a reduced pressure. The distillate could be directly fractionated to obtain the pure acid.

If the hydrophobic organic salt obtained in the preceding step d1) comprises not only the hydrophobic organic salt tris(halosulfonyl)methide, but also a hydrophobic organic salt comprising the anion of the anhydride-forming agent (preferably the anions triflates), then tris(halosulfonyl)methane will be the product, while an acid of the anhydride forming agent (preferably triflic acid) will be a side product of the above product.
Optional step e) recycling the anhydride-forming agent

If an acid of the anhydride-forming agent is obtained from step d2', said acid can then be converted into an anhydride (preferably triflic anhydride) using any method known in the art. The anhydride-forming agent is, in this way, recycled and can be reused. This contributes considerably to the overall economy of the process.
Methanetrisulfonic acid purification method

1. neutraliser l’acide méthanetrisulfonique brut avec une base, ce qui provoque une précipitation d’un sel d’acide méthanetrisulfonique ;
2. recristalliser le sel d’acide méthanetrisulfonique ; et
3. faire passer une solution du sel recristallisé à travers une colonne échangeuse d’ions acide pour obtenir une solution aqueuse d’acide méthanetrisulfonique purifié.

In a second aspect of the invention, a process for purifying crude methanetrisulfonic acid is provided. This method includes the steps of:

1. neutralizing the crude methanetrisulfonic acid with a base, causing precipitation of a methanetrisulfonic acid salt;
2. recrystallize the methanetrisulfonic acid salt; And
3. passing a solution of the recrystallized salt through an acid ion exchange column to obtain an aqueous solution of purified methanetrisulfonic acid.

This purification method is as defined in step a2 in the process for the production of tris(halosulfonyl)methane or its salts defined above.

In embodiments, the purification process may include the step of synthesizing methanetrisulfonic acid to produce the methanetrisulfonic acid mixture. This optional step is as defined in step a1 in the process for the production of tris(halosulfonyl)methane or its salts defined above.

In embodiments, the purification process may further comprise the step of preparing a methanetrisulfonic acid salt with the purified methanetrisulfonic acid. This optional step is as defined in step a3 in the process for the production of tris(halosulfonyl)methane or its salts defined above.
Advantages of the invention

In the development of the process of the present invention, the inventors have discovered the surprising result that mixing together a methanetrisulfonic acid or its salt with an anhydride-forming agent under basic or neutral conditions (preferably in the presence of an organic base) and reacting the resulting mixture with a halogenating agent produces tris(halosulfonyl)methane (and ultimately its salts).

• Le procédé est techniquement plus simple que les procédés classiques et ne requiert pas l’utilisation de composés organiques chlorés hautement toxiques et de SF₄.
• Le procédé ne nécessite pas l’utilisation de réacteurs haute pression.
• Le procédé peut conduire à de bons rendements de dérivés halogénés d’acide méthanetrisulfonique, incluant le tris(fluorosulfonyl)méthane. Le procédé peut être utilisé à une échelle industrielle.
• Le procédé peut permettre la production de tris(halosulfonyl)méthane ou de ses sels à l’aide d’un procédé dans lequel des composés disponibles à bon marché et/ou facilement accessibles, les sels métalliques ; les agents halogénants ; les bases et les solvants sont utilisés. Ceci permet à la quantité des réactifs et produits d’être utilisés à une échelle industrielle.
• Le procédé peut permettre de nouvelles optimisations et un recyclage de plusieurs réactifs utilisés dans le mode opératoire, améliorant ainsi l’économie globale du procédé.

DéfinitionsIn embodiments, in addition to the advantages previously discussed, the method of the present invention may have one or more of the following advantages:

• The process is technically simpler than conventional processes and does not require the use of highly toxic chlorinated organic compounds and SF ₄ .
• The process does not require the use of high pressure reactors.
• The process can lead to good yields of halogenated derivatives of methanetrisulfonic acid, including tris(fluorosulfonyl)methane. The method can be used on an industrial scale.
• The process can enable the production of tris(halosulfonyl)methane or its salts by a process in which inexpensively available and/or easily accessible compounds, metal salts; halogenating agents; bases and solvents are used. This allows the amount of reactants and products to be used on an industrial scale.
• The process may allow for further optimizations and recycling of several reagents used in the procedure, thereby improving the overall economics of the process.

Definitions

The terms "comprising", "having", "including", and "containing" shall be interpreted as open terms (i.e., meaning "including but not limited to") unless otherwise specified.

The indication of ranges of values here is merely intended to serve as a quick method of individually referring to each separate value falling within the range, unless otherwise specified herein, and each separate value is incorporated into the description as if it was individually listed here. Any subsets of values within the ranges are also incorporated into the description as if individually listed here.

Similarly, herein a general chemical structure with various substituents and various moieties listed for those substituents is intended to serve as a quick method of referring individually to each molecule obtained by the combination of any of the moieties for any of the substituents . Each individual molecule is incorporated into the description as if individually listed herein. In addition, all subsets of molecules within the general chemical structures are also incorporated into the description as if individually listed here.

All of the methods described here can be performed in any appropriate order unless otherwise stated here or otherwise clearly contradicted by the context.

Use of all examples, or exemplary language (e.g., "as is") provided herein, is intended merely to better illuminate the invention and does not place any limitation on the scope of the invention. unless otherwise claimed.

No language in the description should be taken to indicate anything not claimed as essential to the practice of the invention.

Here the term “about” has its ordinary meaning. In embodiments, it may mean plus or minus 10% or plus or minus 5% of the qualified numeric value.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

• alkyloxy est alkyl-O-,
• aryloxy est aryl-O-,
• alkyloyl est alkyl-C(=O)-,
• aryloyl est aryl-C(=O)-,
• alkyloyloxy est alkyl-C(=O)-O-,
• aryloyloxy est aryl-C(=O)-O-,
• alkylsulfonyl est alkyl-SO₂-,
• arylsulfonyl est aryl-SO₂-,
• alkylsulfonyloxy est alkyl-SO₂-O-, et
• arylsulfonyloxy est aryl-SO₂-O-.

For clarity, it should be noted that:

• alkyloxy is alkyl-O-,
• aryloxy is aryl-O-,
• alkyloyl is alkyl-C(=O)-,
• aryloyl is aryl-C(=O)-,
• alkyloyloxy is alkyl-C(=O)-O-,
• aryloyloxy is aryl-C(=O)-O-,
• alkylsulfonyl is alkyl-SO ₂ -,
• arylsulfonyl is aryl-SO ₂ -,
• alkylsulfonyloxy is alkyl-SO ₂ -O-, and
• arylsulfonyloxy is aryl-SO ₂ -O-.

Here, the term "alkyl" has its ordinary meaning in the art. It should be noted that, unless otherwise specified, the hydrocarbon chain of the alkyl groups can be linear or branched.

Here, a "haloalkyl" refers to an alkyl group in which one or more (or even all) of the hydrogen atoms are each replaced by a halogen atom, in which the halogen atoms are the same or different l from each other (when more than one halogen atom is present). Halogen atoms include (F), chlorine (Cl), bromine (Br) and iodine (I). Non-limiting examples and preferred embodiments of C ₁ -C ₂₄ haloalkyls include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, 2,2,2-trifluoroethyl and 1,1,1,3,3,3-hexafluoro- 2-propyl.

Here, the term "aryl" has its ordinary meaning in the art. It should be noted that, unless otherwise indicated, aryl groups can contain between 5 and 30 atoms, including carbon and heteroatoms, preferably without heteroatoms, more specifically between 5 and 10 atoms, or contain 5 or 6 atoms.

Other objects, advantages and characteristics of the present invention will become apparent on reading the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.

Description of illustrative embodiments

The present invention is further illustrated by the following non-limiting examples.

More specifically, the following examples describe the synthesis of salts of methanetrisulfonic acid ( Examples 1-4 ), as well as the synthesis of tris(halosulfonyl)methane or its salts of the invention ( Examples 5 and 6 ).

The chemicals used in the following examples are purchased from Sigma-Aldrich ^TM (oleum, potassium carbonate, potassium hydroxide, pyridine, triethylamine, Amberlite IR 120, isopropanol, potassium bifluoride, MgSO ₄ anhydrous), Alfa Aesar ^TM ( acetone, acetic anhydride, tetrabutyl ammonium bromide, sodium hydrogen carbonate, tripropylamine, ethyldiisopropylamine), VWR ^TM (acetonitrile, ethyl acetate, dichloromethane), Apollo Scientific ^TM (triflic anhydride, Et ₃ N×3HF). In all Examples, N ₂ was used as the protective atmosphere.
Example 1: Preparation of potassium methanetrisulphonate from acetone – step a1 )

9 ml (0.1 mole) of acetone was slowly added to 50 ml of a well-stirred 67% oleum; the temperature was controlled to always be below 5°C. First, a yellowish solution was obtained. After 20 minutes at room temperature, a thick suspension of white solid was obtained. The mixture was gradually heated to 85°C then refluxed until the mixture was clear again; gassing ceased at about 3 o'clock. 27 ml of cooled mixture were poured onto 200 g of ice, then neutralized with KOH and K ₂ CO ₃ at pH = 7. The volume was then adjusted to 250 ml, and a fine white precipitate was filtered off and recrystallized from l 'Hot water. Fine shiny needles separated from the cooled solution. The compound was identified as pure potassium methanetrisulfonate monohydrate HC(SO ₃ K) ₃ ×H ₂ O.

The IR characterization of potassium methanetrisulfonate monohydrate is as follows:
IR[ATR-in diamond]/cm ^-1 :3561S, 3490S, 2940S, 1645M, 1261VS, 1240VS, 1226VS, 1094M, 1039S, 1026VS, 824M, 760M, 609S, 549M.
Example 2: Preparation of methanetrisulfonic acid by ion exchange – step a2)

Amberlite IR120 cationic ion exchange resin in H ⁺ form was batch washed with MQ water and allowed to swell in fresh MQ water. It was then loaded onto a column and washed again with 300 ml of water. A saturated solution of 6 g of potassium methanetrisulfonate as prepared in Example 1 in 700 ml of water was passed through the column and afterwards the column was washed with 150 ml of fresh MQ water. The acid-containing fraction was concentrated in vacuo and a brownish oily residue was obtained, which was additionally dried at 0.5 × 10 ^-3 mbar and 80°C to obtain a crystalline solid, which was identified as a methanetrisulfonic acid hydrate.

The NMR characterization of methanetrisulfonic acid hydrate is as follows:
1H NMR (400 MHz, DMSO-d6) δ = 5.90 (m wide, 20H), 4.66 (s, 1H) ^,
13C NMR (101 MHz, DMSO-d6) δ= 90.78.
Example 3: Preparation of triethylammonium methanetrisulphonate – step a3 )

A small part of the oily solution of methanetrisulfonic acid obtained in Example 2 was dissolved in methanol and an excess of triethylamine was added. The mixture was then evaporated to obtain a beige amorphous solid, which was identified as pure triethylammonium methanetrisulfonate -HC(SO ₃ (HNEt ₃ )) ₃ .

The NMR and IR characterization of triethylammonium methanetrisulfonate is as follows:
1H-NMR (400 MHz, CHLOROFORM-d) δ= 9.53 - 7.84 (s wide, 3H), 5.25 (s, 1H), 3.15 (q,J= 7.3Hz, 18H), 1.28 (t,J= 7.3Hz, 27H),
13C NMR (101 M Hz, CHLOROFORM-d) δ= 89.36, 45.84, 8.31.
IR[ATR-in diamond]/cm-1:3042S,2980M,2947M,2883M,2750M,2710M,1463M,1418M,1393M,1358W,1295M,1277M,1232VS,1217VS,1173M,1144W,1083 W, 1066M, 1045M, 1019 VS, 1008M, 899W, 843W, 814M, 750W, 602S, 593M, 542W, 527W.
Example 4: Preparation of pyridinium methanetrisulphonate – step a1) and a2)

One-half 16 ml (0.157 mole) of acetic anhydride was slowly added (over about 30 minutes) to 50 ml of well-stirred 67% oleum contained in a 250 ml reactor under an atmosphere of 'nitrogen. The temperature was then brought gradually to 75° C.; at this temperature, vigorous foaming occurred after about 30 min. The other half of acetic anhydride was then added and the temperature was raised to 95°C. After ¾ hour, the mixture solidified into a cherry red solid. Heating was continued overnight at 95°C. The solid product contained approximately 50% by weight of methanetrisulfonic acid.

A small portion of the solid product was dissolved in ice water and excess pyridine was added. After evaporation, a brown oil was obtained and it was extracted with a 6:1 mixture of acetonitrile:isopropanol. Part of the oil has crystallized and part of the oil has gone into solution. The solution was removed and the solid extracted again with the same 6:1 mixture of acetonitrile:isopropanol. By analysis of the solid and the extracts, pyridinium methanetrisulfonate was found to be the remaining solid. On the contrary, pyridinium sulfoacetate, pyridinium methionate and pyridinium sulfate were extracted into a solvent.

The NMR characterization of pyridinium methanetrisulfonate is as follows:
1H NMR (400 MHz, DEUTERIUM OXIDE) δ = 8.75 (dd, J = 1.5, 6.6 Hz, 6H), 8.53 (tt, J = 1.6, 7.9 Hz, 3H) , 7.99 (dd, J =6.8, 7.8Hz, 6H), 5.23 (s, 1H),
13C NMR (101 MHz, DEUTERIUM OXIDE) δ = 146.39, 141.75, 127.13, 88.15
Example 5: Preparation of tetrabutylammonium tris(fluorosulfonyl)methide – steps b), c) and d)

0.4935 g (1 mmol) of pyridinium methanetrisulphonate, prepared as described in Example 4, was dried at 0.5×10 ^-3 mbar and 80°C. After cooling, 1 ml (6 mmol) of triflic anhydride was added, and the mixture was stirred under nitrogen at room temperature. No reaction or solubilization occurred even after moderate heating. Thus, 0.1 ml of tripropylamine was added, leading to a violent reaction. After stirring at room temperature for 16 hours, a homogeneous dark solution was obtained

After the mixture was stirred for 5 days, the entire mixture was added to 3 ml of Et ₃ N×3HF in which 1 g of KHF ₂ was suspended.

After 16 hours, the entire mixture was poured into a cold saturated solution of sodium hydrogen carbonate and made slightly alkaline (pH≈9). A solution of 3 g of tetrabutylammonium bromide in 10 ml of water was then added. The resulting mixture was extracted with 2×10 ml of ethyl acetate and 2×10 ml of dichloromethane; the combined organic phases were dried with MgSO ₄ anhydride and evaporated. The mixture was analyzed and found to contain predominantly tetrabutylammonium triflate, tetrabutylammonium tris(fluorosulfonyl)methide and tetrabutylammonium fluorosulfonate.

Tetrabutylammonium tris(fluorosulfonyl)methide is a compound of the following formula:
.

The tris(fluorosulfonyl)methide ion had the following spectral properties:
19F NMR (376 MHz, Acetone) δ = 70.41. (ref. PhF, δ = -114.72 ppm)
13C NMR (76 MHz, Acetone) δ = 86.03.
Example 6: Preparation of tetrabutylammonium tris(fluorosulfonyl)methide – steps b), c) and d)

5 g of the solid sulphonation product obtained in Example 4 were dissolved in methanol and an excess of ethyldiisopropylamine was added; the mixture was dried at 0.5 × 10 ^-3 mbar and 80°C. After cooling, the resinous solid was dissolved in 20 ml of 1,2-dichloroethane and 10 ml of triflic anhydride was added. The mixture was then stirred under nitrogen at room temperature. No reaction or homogenization occurred, so 20 mg of dimethylaminopyridine and 10 mg of triphenylphosphine oxide were added, resulting in slow homogenization of the reaction mixture.

After the mixture had been stirred for 4 days, 20 ml of the mixture was added to 25 ml of Et ₃ N×3HF in which 5 g of KHF ₂ had been suspended.

After 4 hours, the entire mixture was poured into a cold saturated solution of sodium hydrogen carbonate and made slightly alkaline (pH≈9). Then, a solution of 10 g of tetrabutylammonium bromide in 10 ml of water was added, and the mixture was extracted with 3 × 20 ml of ethyl acetate and 2 × 20 ml of dichloromethane. The combined organic phases were dried with MgSO ₄ anhydride and evaporated.

The mixture was analyzed and found to contain tetrabutylammonium triflate in the majority, tetrabutylammonium tris(fluorosulfonyl)methide in a considerable amount, and tetrabutylammonium fluorosulfonate in only a small amount.

The tris(fluorosulfonyl)methide ion had the same NMR spectrum as reported for Example 5. In addition, the sample was analyzed by ULPC/MS, a separation between triflate and tris(fluorosulfonyl)methide was performed, and tris(fluorosulfonyl)methane was detected as [MH] ^- =261 in an ES detection mode.

The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Documents

This description refers to a number of documents, the contents of which are hereby incorporated by reference in their entirety. These documents include, but are not limited to:

WO2016031961

Klöter, G.; Pritzkow, H.; Seppelt, K.Angew . Chem. 1980 , 92 , 954., Yagupolskii, YL; Savina, TI Zh. Org. Khim. 1983 , 19 , 79.

Yagupol'skii, YL; Savina, TI; Pavlenko, NO; Pankov, AA; Pazenok, SV Zh. Obshch. Khim. 1991 , 61 , 1512.

Backer, HJ Recl. work Chem. Netherlands 1930 , 49 , 1107., Sartori, P.; Jüschke, R. Journal für Praktische Chemie/Chemiker-Zeitung 1994 , 336 , 373.

US 2333701

Olah, G. and S. Kuhn, Notes. Organic Fluorine Compounds. XXVII. Preparation of Acyl Fluorides with Anhydrous Hydrogen Fluoride. The General Use of the Method of Colson and Fredenhagen. The Journal of Organic Chemistry, 1961. 26 (1): p. 237-238.

Olah, GA, M. Nojima, and I. Kerekes, Synthetic Methods and Reactions; IV. Fluorination of Carboxylic Acids with Cyanuric Fluoride. Synthesis, 1973: p. 487-488.

Oláh, G., S. Kuhn, and S. Beke, Darstellung und Untersuchung organischer Fluorverbindungen XX. Darstellung von Säurefluoriden. Chemische Berichte, 1956. 89 (4): p. 862-864.

Olah, GA, et al., Synthetic methods and reactions. 63. Pyridinium poly(hydrogen fluoride) (30% pyridine-70% hydrogen fluoride): a convenient reagent for organic fluorination reactions. The Journal of Organic Chemistry, 1979. 44 (22): p. 3872-3881.

Hudlicky, M., Fluorination with diethylaminosulfur trifluoride and related aminofluorosulforanes. Organic Reactions, 1988. 35 : p. 513-637.

Claims (75)

A method of producing tris(halosulfonyl)methane or a salt thereof, comprising the steps of:
To. obtaining methanetrisulfonic acid or a salt thereof;
b. reacting methanetrisulfonic acid or a salt thereof with an anhydride-forming agent under basic or neutral conditions to produce a mixed anhydride;
vs. halogenating the mixed anhydride to produce tris(halosulfonyl)methane; And
d. optionally, reacting tris(halosulfonyl)methane with a base to produce a tris(halosulfonyl)methane salt,
wherein tris(halosulfonyl)methane is represented by general formula (I):

wherein R ¹ , R ² and R ³ each independently represent a halogen atom, and
the tris(halosulfonyl)methane salt has the following formula (II):

in which R ¹ , R ² and R ³ are as defined above and CAT ⁺ represents an organic or inorganic cation. Process according to Claim 1, in which CAT ⁺ represents Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Al ³⁺ , Zn ²⁺ or an organic cation. Process according to one of claims 1 or 2, in which for the two formulas (I) and (II), each of R ¹ , R ² and R ³ represents F or Cl, more preferably F. A method according to any of claims 1 to 3, wherein step a) comprises the steps of:
a1) synthesis of methanetrisulfonic acid and
a2) purification of the methanetrisulfonic acid,
a3) optionally, preparation of the methanetrisulfonic acid salt. Process according to Claim 4, in which step a1 comprises the sulphonation of an organic compound containing one or more acetyl groups with oleum or another source of SO ₃ , first at a low temperature, such as below 5°C, then at a higher temperature to obtain a mixture of methanetrisulfonic acid, sulfuric acid, methionic acid and other secondary products. Process according to claim 4 or 5, wherein step a2) comprises the preparation of a salt of methanetrisulfonic acid and the use of an acidic ion exchange resin to produce the methanetrisulfonic acid. A method according to claim 6, wherein in step a2):
i. the reaction mixture is neutralized with a base, which causes precipitation of a methanetrisulfonic acid salt,
ii. recrystallization of the methanetrisulfonic acid salt, and
iii. a solution of the salt is then prepared and passed through an acid ion exchange column to obtain an aqueous solution of methanetrisulfonic acid. Process according to claim 7, wherein the base in step i) is a tertiary amine base, preferably pyridine, or preferably a potassium base, such as potassium hydroxide, potassium carbonate or hydrogen potassium carbonate. Process according to one of Claims 7 or 8, in which, during stage ii), the precipitated salt is recrystallized from hot water. A method according to any of claims 7 to 9, wherein the ion exchange is carried out on an aqueous solution. A method according to any of claims 7 to 10, wherein the precipitated salt is soluble in organic solvents, and an organic solvent is used during the ion exchange. Process according to any one of Claims 7 to 11, in which the ion exchange column used in step ii) is Amberlite ^TM , for example Amberlite ^TM IR120, or Dowex ^TM . Process according to any one of Claims 7 to 12, in which, in step a2), the methanetrisulphonic acid is isolated in the form of its salt, preferably its pyridine salt. A process according to any of claims 4 to 13, wherein in cases where a methanetrisulphonic acid salt is desired, and step a2) produces methanetrisulphonic acid, a methanetrisulphonic acid salt is produced in step a3) by reacting methanetrisulphonic acid with a base. A process according to any one of claims 1 to 14, wherein during step b the methanetrisulphonic acid or salt thereof is converted into a substituted sulphonic acid mixed anhydride by reaction with a forming agent of strong anhydride in the presence of an organic base, thus making it possible to produce a mixed anhydride of formula (I) above in which each of R ¹ , R ² and R ³ represents an -OR ⁴ group, R ⁴ being a functional group which depends on the nature of the anhydride-forming agent used in the reaction, and R ⁴ preferably being a good leaving group, preferably one of the best leaving groups in organic chemistry. A process according to claim 15, wherein the anhydride-forming agent is an acylating agent, a sulphonylating agent, a sulfinylating agent, a phosphanylating agent or a phosphorylating agent, preferably a sulphonylating agent. Process according to Claim 16, in which R ⁴ represents an acyl group, a sulphinyl group, a sulphonyl group, a sulfanyl group, a phosphanyl group or a phosphoryl group, preferably a sulphonyl group. Process according to Claim 17, in which the acyl group is a group of the formula -C(=O)R ⁵ , in which R ⁵ is a functional group which depends on the nature of the acylating agent used in the reaction. Process according to Claim 18, in which R ⁵ is a halogen atom, perfluorinated alkyl, perfluorinated aryl or perfluorinated heteroaryl, preferably, R ⁵ being a halogen atom, preferably F, or a perfluorinated alkyl. Process according to one of Claims 18 or 19, in which the acylating agent is chosen from: acyl isocyanates, carboxylic halides, carboxylic anhydrides, carbonyl dihalides, oxalyl halides and their mixtures, preferably trifluoroacetyl fluoride, trifluoroacetyl chloride, carbonyl difluoride, oxalyl fluoride, and mixtures thereof. Process according to Claim 17, in which the sulfinyl group is a group of the formula -S(=O)-R ⁶ , in which R ⁶ is a functional group which depends on the nature of the sulfinylating agent used in the reaction. Process according to Claim 21, in which R ⁶ is a halogen atom, preferably F. Process according to one of Claims 21 or 22, in which the sulfinylating agent is thionyl halide, such as thionyl fluoride S(=O)F ₂ . Process according to Claim 17, in which the sulfonyl group is a group of the formula -S(=O) ₂ -R ⁷ , in which R ⁷ is a functional group which depends on the nature of the sulfonylating agent used in the reaction. Process according to Claim 24, in which R ⁷ is a halogen atom or a branched or linear C _1-24 alkyl, perfluorinated. Process according to one of Claims 24 or 25, in which the sulphonylating agent is chosen from sulphonic halides, sulphonic anhydrides, sulphonyl isocyanates, inorganic acid fluorides and their mixtures. Process according to any one of Claims 24 to 26, in which the sulfonylating agent is chosen from sulfuryl fluoride, sulfuryl fluoride chloride, fluorosulfonyl anhydride, alkanesulfonyl anhydrides, alkanesulfonyl halides, arylsulfonyl anhydrides, arylsulfonyl halides, perfluoroalkanesulfonyl anhydrides, perfluoroalkanesulfonyl fluorides, perfluoroalkanesulfonyl chlorides and mixtures thereof. A method according to any of claims 24 to 27, wherein the sulfonylating agent is methane sulfonyl chloride, methane sulfonyl anhydride, toluene sulfonyl chloride, toluene sulfonyl anhydride, triflic anhydride, triflic fluoride or triflic chloride. A method according to any of claims 24 to 28, wherein the sulfonylating agent is triflic anhydride. Process according to Claim 17, in which the sulfanyl group is a group of the formula -S(R ⁸ ) ₃ in which the R ⁸ are each a functional group which depends on the nature of the sulfanylating agent used in the reaction. Process according to Claim 30, in which R ⁸ is a halogen atom, preferably F. Process according to claim 30 or 31, in which the sulphanilating agent is a sulfur tetrahalide, such as sulfur tetrafluoride. Process according to Claim 17, in which the phosphanyl group is a group of the formula -OP-(R ⁹ ) _n , in which n is 2 or 4 and in which R ⁹ is a functional group which depends on the nature of the agent phosphanylant used in the reaction. Process according to Claim 33, in which R ⁹ is a halogen atom, preferably F. Process according to one of Claims 33 or 34, in which the phosphanylating agent is chosen from phosphorus pentahalides, such as phosphorus pentafluoride PF ₅ , and phosphorus trihalides, such as phosphorus trifluoride PF ₃ and phosphorus trichloride, and mixtures thereof. Process according to claim 17, in which the phosphoryl group is a group of formula -P(=O)-(R ¹⁰ ) ₂ , in which the R ¹⁰ are each a functional group which depends on the nature of the phosphorylating agent used in the reaction. Process according to Claim 36, in which R ¹⁰ is a halogen atom, preferably F. Process according to one of Claims 36 or 37, in which the phosphorylating agent is a phosphoryl halide, such as phosphoryl fluoride P(=O)F ₃ . Process according to any one of Claims 15 to 38, in which the reaction of step b is carried out in the presence of an unreactive organic solvent or without dilution, that is to say without the use of a solvent, for example in cases where the anhydride-forming agent is liquid and is used in excess. Process according to any one of claims 15 to 39, in which an organic salt of methanetrisulfonic acid is used in step b). Process according to Claim 40, in which the organic salt of methanetrisulfonic acid has been prepared using tertiary amines. A process according to any of claims 15 to 41, wherein the reaction of step b takes place under basic conditions. Process according to any one of claims 15 to 42, in which an organic base catalyst which promotes the reaction of step b is added, for example pyridine derivatives such as dimethylaminopyridine, pyrrolidinopyridine and guanidinopyridines; imidazole derivatives; triphenylphosphine oxide; guanidine; tripropylamine; and amidine bases. Process according to Claim 43, in which the organic base catalyst is dimethylaminopyridine, pyrrolidinopyridine, tripropylamine or a mixture thereof. A method according to any of claims 15 to 44, wherein a pressure vessel is used during step b. A process according to any one of claims 15 to 45, wherein reaction step b is carried out by mixing the methanetrisulfonic acid or its salt with the anhydride-forming agent for as long as necessary to produce the mixed anhydride. A method according to any of claims 15 to 46, wherein the mixing takes between 5 hours and 6 days, more preferably between 16 hours and 5 days. A process according to any of claims 1 to 47, wherein during step c the mixed anhydride is reacted with a halogenating agent to produce tris(halosulfonyl)methane. A process according to claim 48, wherein the tris(halosulfonyl)methane is tris(fluorosulfonyl)methane. Process according to one of Claims 48 or 49, in which the halogenating agent is a fluorinating agent. Process according to Claim 50, in which the fluorinating agent is chosen from hydrogen fluoride and its salts, preferably ammonium, substituted ammonium, lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium , zinc, antimony and arsenic; aluminum fluorides, potassium fluorides such as KF and KH ₂ F, and potassium hydrogen difluorides such as KF and KHF ₂ ; complex inorganic and organic fluorides such as hexafluorophosphates, hexafluorosilicates, hexafluoroaluminates and tetrafluoroborates; polyhydrogen fluorides; complex salts of amines with hydrofluoric acid, such as pyridinium and triethylammonium polyhydrogen fluorides, and liquid complexes of organic amines with hydrogen fluoride, such as: Et ₃ N×xHF, preferably Et ₃ N ×3HF, Pyr×xHF; reactive inorganic and organic acid fluorides, such as PF ₅ , POF ₃ , SOF ₂ , FSO ₃ H, COF ₂ and FCOCOF, organic and inorganic; sulfur tetrafluoride and its organic derivatives, such as DAST, diethylaminosulfur trifluoride and morpholinosulfur trifluoride; cyanuric fluoride, acetyl fluoride; benzoyl fluoride; trifluoroacetyl fluoride; methanesulfonyl fluoride; triflic fluoride; benzoyl fluoride; benzenesulfonyl fluoride; toluenesulfonyl fluoride; and their mixtures. Process according to one of Claims 50 or 51, in which the fluorinating agent is chosen from complex salts of amines with hydrofluoric acid, complex inorganic and organic fluorides and polyhydrogen fluorides. Process according to any one of Claims 50 to 52, in which the fluorinating agent is a liquid complex of organic amines with hydrogen fluoride, such as: Et ₃ N×xHF, preferably Et ₃ N×3HF, and Pyr×xHF. A method according to any of claims 50 to 53, wherein the fluorinating agent is Et ₃ N×3HF in which KHF ₂ is optionally suspended. A method according to any of claims 48 to 54, wherein the mixed anhydride is halogenated by mixing it with the halogenating agent for as long as necessary to halogenate the mixed anhydride. A method according to claim 55, wherein mixing takes between 2 hours and 20 days, more preferably between 4 hours and 16 hours. A method according to any of claims 1 to 56, wherein optional step d is performed. Process according to Claim 57, in which, during step d, the halogenated derivative is isolated in the form of a free acid or in the form of an organic or inorganic salt. Process according to Claim 58, in which the tris(halosulfonyl)methane is a strongly acidic compound, for example tris(fluorosulfonyl)methane), which is neutralized during step d by an inorganic or organic base to produce the organic salt or inorganic. Process according to Claim 59, in which the reaction mixture obtained after halogenation is neutralized or made slightly alkaline to ensure that all the acids are in their anionic form, after which the separation of anions is carried out by the addition of the organic base, which leads to the precipitation of a hydrophobic organic salt comprising an organic cation originating from the organic base and a hydrophobic anion originating from the tris(halosulfonyl)methane. Process according to claim 60, in which the hydrophobic organic salt is then isolated by filtration or by extraction with an organic solvent immiscible with water. Process according to any one of Claims 59 to 61, in which the organic base is chosen from monoalkylammonium, dialkylammonium, trialkylammonium, tetraalkylammonium salts, preferably tetrabutylammonium bromide, tetraalkylphosphonium salts and mixtures thereof. A method according to any of claims 59 to 62, wherein a resin immobilized quaternary ammonium salt - anion exchange resin is used. Process according to any one of claims 59 to 63, in which the tris(halosulfonyl)methane is isolated in the form of a hydrophobic organic salt, A method according to claim 64, wherein the hydrophobic organic salt is in the form of a tris(halosulfonyl)methide. A method according to claim 65, wherein the hydrophobic organic salt further comprises an organic salt of the anhydride-forming agent anion. A process according to claim 64 or 65, wherein tetrabutylammonium bromide is used as the organic base, and the resulting hydrophobic organic salt comprises tetrabutylammonium tris(halosulfonyl)methide, preferably tetrabutylammonium tris(fluorosulfonyl)methide. A method according to claim 67, wherein the hydrophobic organic salt further comprises tetrabutyl ammonium triflate. A method according to any of claims 64 to 68, wherein the hydrophobic organic salt is further reacted with a suitable metal base to produce an inorganic salt. Process according to Claim 69, in which the metal base is chosen from alkali and alkaline earth metal hydroxides, alkoxides, substituted amides, alkyl metals and Grignard reagents. Process according to one of claims 69 or 70, in which the hydrophobic organic salt is mixed with a solution of at least 1 equivalent of the metallic base, preferably an alkaline or alkaline-earth base, more preferably LiOH, NaOH , KOH, RbOH, CsOH, Be(OH) ₂ , Mg(OH) ₂ , Ca(OH) ₂ , Sr(OH) ₂ , Ba(OH) ₂ , Al(OH) ₃ , Zn(OH) ₂ or a alkoxide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al or Zn. A method according to any of claims 58 to 71, wherein the organic or inorganic salt is purified using crystallization and any suitable selective extraction method. Process according to any one of Claims 64 to 68, in which the hydrophobic organic salt is dissolved in cold concentrated sulfuric acid, then the volatile compounds, removed by distillation at reduced pressure, after which the distillate is directly fractionated to obtain pure acid. A method according to claim 73, wherein the hydrophobic organic salt comprises not only the hydrophobic organic salt tris(halosulfonyl)methide, but also a hydrophobic organic salt comprising the anion of the anhydride-forming agent, preferably the triflate anions , such that tris(halosulfonyl)methane is a product, while an acid of the anhydride forming agent, preferably triflic acid, is a side product of the above product. A method according to claim 74, wherein the acid of the anhydride-forming agent, preferably triflic acid, is then converted to an anhydride, preferably triflic anhydride.