TMB alkyl sulfonic acid alkali metal salt and preparation method thereof

Abstract

The invention provides TMB (Tetramethylbenzidine) alkyl sulfonic acid alkali metal salt and a preparation method thereof, and belongs to the technical field of compound preparation. The TMB alkyl sulfonic acid alkali metal salt is successfully prepared through the four steps of alkylation reaction, alkaline water extraction, solvent extraction and salt forming reaction. The synthesis process route is high in yield and high in purity, the prepared TMB alkyl sulfonic acid alkali metal salt is good in water solubility, no organic solvent is used for assisting dissolving in use, the defects in the prior art are overcome, and application in water aqua is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of compound preparation, and in particular to a TMB alkyl sulfonic acid alkali metal salt and a preparation method thereof. Background Art

[0002] 3,3',5,5'-Tetramethylbenzidine, abbreviated as TMB, is non-toxic and widely used in dyes, fluorescent agents, photosensitive materials, medicine and other fields. In biological analysis, it is mainly used for the detection of blood, urine and environment. Its structural formula is as follows:

[0003]

[0004] The main problem with the existing application of TMB is that the compound is poorly soluble in water. Even if it is salified with hydrochloric acid to form TMB hydrochloride, its solubility in water is still low. When used, a large amount of organic solvent is required to aid dissolution, which wastes reagents and affects the further application of the compound. Therefore, how to improve the water solubility of TMB by modifying the TMB structure so that it is beneficial for use in aqueous preparations is a technical problem that needs to be solved at present. Summary of the invention

[0005] The object of the present invention is to provide a TMB alkylsulfonic acid alkali metal salt and a preparation method thereof, so as to solve the technical problems of poor water solubility of TMB and low yield and low purity of existing products.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing TMB alkyl sulfonic acid alkali metal salt, comprising the following steps:

[0008] 1) mixing 3,3',5,5'-tetramethylbenzidine and alkali metal salt of halogenated alkylsulfonic acid in a reaction solvent, and performing an alkylation reaction under the action of a catalyst to obtain a reaction solution;

[0009] 2) adding an alkaline aqueous solution to the reaction solution, mixing, separating and extracting the alkaline aqueous layer, repeating at least once, combining the alkaline aqueous layers, and obtaining an alkaline aqueous extract;

[0010] 3) adding acid water to the alkaline water extract to adjust the pH, adding the extraction solution, mixing, collecting the organic layer, drying and concentrating to obtain TMB alkyl sulfonic acid;

[0011] 4) TMB alkyl sulfonic acid and alkali metal bicarbonate are mixed in a salt-forming solvent to carry out a salt-forming reaction, and the reaction product is dried to obtain TMB alkyl sulfonic acid alkali metal salt.

[0012] Furthermore, the chemical formula of the alkali metal halogenated alkyl sulfonate is XR-SO3M, wherein X comprises Cl or Br, R is a C1-C10 alkyl group, and M comprises Li, Na or K.

[0013] Further, the molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal salt of halogenated alkyl sulfonate is 1:0.9 to 1:1.5, and the reaction solvent comprises one or more of dichloromethane, chloroform, acetonitrile, ethyl acetate, tetrahydrofuran, dioxane, triethylamine and N,N-dimethylformamide;

[0014] The catalyst comprises one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium hydrogen sulfate.

[0015] Furthermore, the molar ratio of the 3,3',5,5'-tetramethylbenzidine to the catalyst is 1:0.1 to 1:1;

[0016] The mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the reaction solvent is 1g:5-30mL;

[0017] The temperature of the alkylation reaction is 35 to 100° C., and the time of the alkylation reaction is 1 to 24 hours.

[0018] Furthermore, the mass concentration of the alkaline aqueous solution is 1-10%, and the alkali in the alkaline aqueous solution is one or more of alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates and alkali metal acetates;

[0019] The mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the alkaline aqueous solution is 1 g:5-30 mL.

[0020] Furthermore, in the step 3), the acid water is prepared by preparing acid and water, the acid comprises one or more of hydrochloric acid, sulfuric acid and acetic acid, the volume ratio of the acid to water is 1:3 to 1:10, and the pH is adjusted to 2 to 7.

[0021] Furthermore, the extraction solution comprises one or more of dichloromethane, chloroform and ethyl acetate, and the mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the extraction solution is 1 g:5-30 mL.

[0022] Furthermore, the alkali metal bicarbonate comprises one or more of lithium bicarbonate, sodium bicarbonate and potassium bicarbonate, the salt-forming solvent comprises an organic solvent and water, the organic solvent comprises one or more of dichloromethane, chloroform, methanol, ethanol, acetone, acetonitrile, ethyl acetate, tetrahydrofuran and dioxane, and the volume percentage of the water and the organic solvent is 1 to 5%.

[0023] Furthermore, the temperature of the salt-forming reaction is 35 to 80° C., and the time of the salt-forming reaction is 1 to 24 hours;

[0024] The molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal bicarbonate is 1:1 to 1:2;

[0025] The usage ratio of the 3,3',5,5'-tetramethylbenzidine and the salt-forming solvent is 1g:5-30mL.

[0026] The invention also provides a TMB alkylsulfonic acid alkali metal salt.

[0027] Beneficial effects of the present invention:

[0028] 1) The present invention provides a method for preparing TMB alkyl sulfonic acid alkali metal salt, and the synthetic process route has high yield and high purity;

[0029] 2) The present invention discloses a TMB alkylsulfonic acid alkali metal salt, which has readily available raw materials, a simple synthesis method, mild conditions, and is easy to operate, and can be produced on a large scale;

[0030] 3) The TMB alkylsulfonic acid alkali metal salt of the present invention has good water solubility and does not require organic solvent for dissolution during use, thus overcoming the shortcomings of the prior art and being beneficial for application in aqueous preparations.

[0031] It can be seen that the present invention provides a water-soluble TMB alkyl sulfonic acid alkali metal salt. Further, it is necessary to develop a preparation method of TMB alkyl sulfonic acid alkali metal salt with high yield and high purity and capable of mass production to make it more beneficial for application in aqueous preparations. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing TMB alkyl sulfonic acid alkali metal salt, comprising the following steps:

[0033] 1) mixing 3,3',5,5'-tetramethylbenzidine and alkali metal salt of halogenated alkylsulfonic acid in a reaction solvent, and performing an alkylation reaction under the action of a catalyst to obtain a reaction solution;

[0034] 2) adding an alkaline aqueous solution to the reaction solution, mixing, separating and extracting the alkaline aqueous layer, repeating at least once, combining the alkaline aqueous layers, and obtaining an alkaline aqueous extract;

[0035] 3) adding acid water to the alkaline water extract to adjust the pH, adding the extraction solution, mixing, collecting the organic layer, drying and concentrating to obtain TMB alkyl sulfonic acid;

[0036] 4) TMB alkyl sulfonic acid and alkali metal bicarbonate are mixed in a salt-forming solvent to carry out a salt-forming reaction, and the reaction product is dried to obtain TMB alkyl sulfonic acid alkali metal salt.

[0037] In the present invention, the preparation reaction formula of the TMB alkyl sulfonic acid alkali metal salt is as follows:

[0038]

[0039] In the formula, X is Cl or Br; R is a C1-C10 alkyl group; and M is lithium, sodium or potassium.

[0040] In the present invention, the chemical formula of the alkali metal halogenated alkyl sulfonate is XR-SO3M, wherein X comprises Cl or Br, R is a C1-C10 alkyl group, and M comprises Li, Na or K. The alkali metal halogenated alkyl sulfonate is preferably one of sodium chloromethanesulfonate, sodium bromomethanesulfonate, sodium bromoethanesulfonate, sodium chloroethanesulfonate, sodium bromopropanesulfonate and sodium bromobutanesulfonate.

[0041] In the present invention, since the TMB molecule contains two amino groups, the amino group at one end of TMB is derivatized with a water-soluble alkyl sulfonic acid, which is bound to improve the water solubility of TMB and solve the technical problem of poor water solubility of TMB.

[0042] In the present invention, the molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal salt of halogenated alkylsulfonic acid is 1:0.9 to 1:1.5, preferably 1:1 to 1:1.3, and more preferably 1:1.2.

[0043] In the present invention, the reaction solvent comprises one or more of dichloromethane, chloroform, acetonitrile, ethyl acetate, tetrahydrofuran, dioxane, triethylamine and N,N-dimethylformamide, preferably one or more of dichloromethane, chloroform, acetonitrile, ethyl acetate and tetrahydrofuran.

[0044] In the present invention, the catalyst comprises one or more of benzyltriethylammonium chloride (TEBA), tetrabutylammonium bromide (TBAB) and tetrabutylammonium hydrogen sulfate (TBAHS), preferably benzyltriethylammonium chloride (TEBA).

[0045] In the present invention, the molar ratio of the 3,3',5,5'-tetramethylbenzidine to the catalyst is 1:0.1 to 1:1, preferably 1:0.2 to 1:0.6, and more preferably 1:0.3 to 1:0.5.

[0046] In the present invention, the mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the reaction solvent is 1 g:5-30 mL, preferably 1 g:8-16 mL, and more preferably 1 g:10-12 mL.

[0047] In the present invention, the temperature of the alkylation reaction is 35 to 100° C., preferably 40 to 85° C., and more preferably 50 to 60° C.; the time of the alkylation reaction is 1 to 24 h, preferably 2 to 12 h, and more preferably 5 to 10 h.

[0048] In the present invention, the mass concentration of the alkaline aqueous solution is 1-10%, preferably 2-8%, and more preferably 4-6%; the alkali in the alkaline aqueous solution is one or more of alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates and alkali metal acetates, preferably alkali metal carbonates or alkali metal bicarbonates.

[0049] In the present invention, the mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the alkaline aqueous solution is 1 g:5-30 mL, preferably 1 g:10-20 mL, and more preferably 1 g:12-18 mL.

[0050] In the present invention, in the step 3), the acid water is prepared by preparing an acid and water, wherein the acid comprises one or more of hydrochloric acid, sulfuric acid and acetic acid, preferably hydrochloric acid; the volume ratio of the acid to water is 1:3 to 1:10, preferably 1:4 to 1:8, and further preferably 1:5 to 1:6; and the pH is adjusted to 2 to 7, preferably 4 to 6.

[0051] In the present invention, the extraction solution comprises one or more of dichloromethane, chloroform and ethyl acetate, preferably dichloromethane; the mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the extraction solution is 1g:5-30mL, preferably 1g:10-20mL, and more preferably 1g:12-18mL.

[0052] In the present invention, the alkali metal bicarbonate comprises one or more of lithium bicarbonate, sodium bicarbonate and potassium bicarbonate, preferably lithium bicarbonate; the salt-forming solvent comprises an organic solvent and water, and the organic solvent comprises one or more of dichloromethane, chloroform, methanol, ethanol, acetone, acetonitrile, ethyl acetate, tetrahydrofuran and dioxane, preferably one or more of dichloromethane, chloroform, methanol, ethanol and acetone;

[0053] The volume percentage of the water and the organic solvent is 1-5%, preferably 2-4%, and more preferably 3%.

[0054] In the present invention, the temperature of the salt-forming reaction is 35 to 80° C., preferably 40 to 75° C., and more preferably 50 to 60° C.; the time of the salt-forming reaction is 1 to 24 h, preferably 2 to 12 h, and more preferably 5 to 10 h.

[0055] In the present invention, the molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal bicarbonate is 1:1 to 1:2, preferably 1:1.2 to 1:1.8, and more preferably 1:1.4 to 1:1.6.

[0056] The usage ratio of the 3,3',5,5'-tetramethylbenzidine to the salt-forming solvent is 1 g:5-30 mL, preferably 1 g:10-25 mL, and more preferably 1 g:15-20 mL.

[0057] The invention also provides a TMB alkylsulfonic acid alkali metal salt.

[0058] The present invention discloses a TMB alkyl sulfonic acid alkali metal salt, which is prepared by alkylation reaction, alkaline water extraction, solvent extraction and salt-forming reaction. In the alkylation reaction, the starting raw material 3,3',5,5'-tetramethylbenzidine and the halogenated alkyl sulfonate are catalyzed by a preferred catalyst, according to a preferred molar ratio, a preferred reaction solvent, a preferred reaction temperature and a reaction time, the raw materials are fully reacted without residue, and the purity of the reaction product is more than 85%; in the alkaline water extraction step of the present invention, the product purity is more than 90% through the preferred alkaline water and the preferred mass volume ratio, and there is no product residue in the reaction solution; in the solvent extraction step of the present invention, the appropriate pH is adjusted by the preferred acid water, the preferred extraction solvent, the product purity is more than 95%, and there is no product in the water phase; in the salt-forming reaction of the present invention, the product purity is more than 99% through the preferred salt-forming solvent, the preferred alkali metal salt, the preferred reaction ratio, the preferred reaction temperature and time, and the total yield is more than 90%, which is beneficial to the application in water preparations.

[0059] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0060] Example 1: Preparation of TMB lithium methanesulfonate;

[0061] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of acetonitrile to the reaction bottle. Add 13.0 g of sodium chloromethanesulfonate and TEBA under stirring. 13.6 grams, control the temperature at 60°C to react for 5 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 5% sodium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 25% sulfuric acid aqueous solution to the alkaline water solution, stir well, adjust the pH to 6, add 480 mL of dichloromethane, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / methanol to the product, add 8.8 grams of lithium bicarbonate, stir well, control the temperature at 45°C to react for 8 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB lithium methanesulfonate, weighing 30.8 grams, with a yield of 90.6% and a purity of 99.23%.

[0062] Example 2: Preparation of TMB sodium methanesulfonate;

[0063] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine to the reaction bottle, add 240 mL of chloroform, stir, add 20.0 g of sodium bromomethanesulfonate, add TBAB 16.1 grams, control the temperature at 60°C to react for 8 hours. After the reaction is completed, cool the reaction solution to room temperature; add 360 mL of 1% sodium carbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 15% hydrochloric acid aqueous solution to the alkaline water solution, stir well, adjust the pH to 5, add 240 mL of ethyl acetate, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / ethanol to the product, add 10.9 grams of sodium bicarbonate, stir well, control the temperature at 70°C to react for 3 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB sodium methanesulfonate, weighing 32.5 grams, with a yield of 91.3% and a purity of 99.15%.

[0064] Example 3: Preparation of TMB potassium methanesulfonate;

[0065] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of dichloromethane to the reaction bottle, add 13.0 g of sodium chloromethanesulfonate and 17.0 g of TBAHS under stirring, and react at 40°C for 16 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 5% potassium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 20% hydrochloric acid to the alkaline water solution The aqueous solution was fully stirred, the pH was adjusted to 4, 360 mL of dichloromethane was added, the mixture was stirred, extracted, separated, the organic layer was collected, the operation was repeated once, the organic layers were combined, and concentrated to dryness to obtain the product; the product was added to 500 mL of 1% water / acetonitrile, 13.0 g of potassium bicarbonate was added, the mixture was fully stirred, the temperature was controlled at 75 ° C to react for 2 hours, the mixture was cooled to room temperature, filtered, the filter cake was collected, and dried to obtain TMB potassium methanesulfonate, which weighed 33.8 g, with a yield of 90.8% and a purity of 99.46%.

[0066] Example 4: Preparation of TMB lithium ethanesulfonate;

[0067] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of acetonitrile to the reaction bottle, add 26.6 g of sodium 2-bromoethanesulfonate and 10.1 g of TBAHS under stirring, and react at 60°C for 8 hours. After the reaction is completed, cool the reaction solution to room temperature; add 300 mL of 2% potassium carbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 25% hydrochloric acid aqueous solution to the alkaline water solution The solution was fully stirred, the pH was adjusted to 2, 480 mL of ethyl acetate was added, stirred, extracted, separated, the organic layer was collected, the operation was repeated once, the organic layers were combined, and concentrated to dryness to obtain the product; the product was added to 500 mL of 1% water / acetone, 7.5 g of lithium bicarbonate was added, the mixture was fully stirred, the temperature was controlled at 40°C, the reaction was performed for 12 hours, the mixture was cooled to room temperature, filtered, the filter cake was collected, and dried to obtain TMB lithium ethanesulfonate, which weighed 32.4 g, with a yield of 91.3% and a purity of 99.32%.

[0068] Example 5: Preparation of TMB Sodium Ethylsulfonate;

[0069] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of dioxane to the reaction bottle. Add 18.1 g of sodium 2-chloroethanesulfonate and TBAB under stirring. 9.7 grams, control the temperature at 85°C to react for 2 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 6% potassium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 30% hydrochloric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 3, add 400 mL of dichloromethane, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / methanol to the product, add 9.2 grams of sodium bicarbonate, stir thoroughly, control the temperature at 50°C to react for 7 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB sodium ethanesulfonate, weighing 34.0 grams, with a yield of 91.7% and a purity of 99.19%.

[0070] Example 6: Preparation of TMB potassium acetate;

[0071] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of triethylamine to the reaction bottle. Add 27.7 g of sodium 2-bromoethanesulfonate and TEBA under stirring. 8.2 grams, control the temperature at 80°C to react for 3 hours. After the reaction is completed, cool the reaction solution to room temperature; add 240 mL of 3% potassium carbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 30% hydrochloric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 5, add 350 mL of ethyl acetate, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / ethanol to the product, add 11.0 grams of potassium bicarbonate, stir thoroughly, control the temperature at 65°C to react for 6 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB potassium ethanesulfonate, weighing 35.2 grams, with a yield of 91.1% and a purity of 99.03%.

[0072] Example 7: Preparation of TMB lithium propanesulfonate;

[0073] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of acetonitrile to the reaction bottle. Add 22.6 g of sodium 3-bromopropanesulfonate and TBAB under stirring. 19.3 grams, control the temperature at 60°C to react for 8 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 3% sodium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 15% sulfuric acid aqueous solution to the alkaline water solution, stir well, adjust the pH to 6, add 240 mL of dichloromethane, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 1% water / acetonitrile 500 mL to the product, add 10.2 grams of lithium bicarbonate, stir well, control the temperature at 75°C to react for 5 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB lithium propanesulfonate, weighing 33.3 grams, with a yield of 90.3% and a purity of 99.12%.

[0074] Example 8: Preparation of TMB Sodium Propane Sulfonate;

[0075] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of N,N-dimethylformamide to the reaction bottle. Add 27.1 g of sodium 3-bromopropanesulfonate and TEBA under stirring. 16.3 grams, control the temperature at 75°C to react for 6 hours. After the reaction is completed, cool the reaction solution to room temperature; add 300 mL of 3% sodium carbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water for standby use; add 5% hydrochloric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 3, add 300 mL of ethyl acetate, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 1% water / acetone 500 mL to the product, add 12.6 grams of sodium bicarbonate, stir thoroughly, control the temperature at 40°C to react for 10 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB sodium propanesulfonate, weighing 35.6 grams, with a yield of 92.6% and a purity of 99.15%.

[0076] Example 9: Preparation of TMB Potassium Propane Sulfonate;

[0077] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of triethylamine to the reaction bottle, add 29.4 g of sodium 3-bromopropanesulfonate and 20.4 g of TBAHS under stirring, and react at 70°C for 4 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 3% potassium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 10% sulfuric acid to the alkaline water solution The aqueous solution was fully stirred, the pH was adjusted to 4, 350 mL of dichloromethane was added, stirred, extracted, separated, the organic layer was collected, the operation was repeated once, the organic layers were combined, and concentrated to dryness to obtain the product; the product was added to 500 mL of 1% water / acetonitrile, 15.0 g of potassium bicarbonate was added, the mixture was fully stirred, the temperature was controlled at 65 ° C to react for 6 hours, the mixture was cooled to room temperature, filtered, the filter cake was collected, and dried to obtain TMB potassium propanesulfonate, which weighed 36.5 g, with a yield of 91.2% and a purity of 99.33%.

[0078] Example 10: Preparation of TMB lithium butanesulfonate;

[0079] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine to the reaction bottle, add 240 g of ethyl acetate, stir, add 24.1 g of sodium 4-bromobutane-1-sulfonate, add TBAHS 6.8 grams, control the temperature at 55°C to react for 12 hours, and after the reaction is completed, cool the reaction solution to room temperature; add 320 mL of 3% potassium carbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 20% hydrochloric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 4, add 400 mL of dichloromethane, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / methanol to the product, add 13.6 grams of lithium bicarbonate, stir thoroughly, control the temperature at 55°C to react for 6 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB butanesulfonic acid lithium, weighing 34.6 grams, with a yield of 90.6% and a purity of 99.34%.

[0080] Example 11: Preparation of TMB sodium butanesulfonate;

[0081] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of tetrahydrofuran to the reaction bottle. Add 27.7 g of sodium 4-bromobutane-1-sulfonate and TEBA under stirring. 5.4 grams, control the temperature at 60°C to react for 6 hours. After the reaction is completed, cool the reaction solution to room temperature; add 480 mL of 3% sodium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water for use; add 10% hydrochloric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 5, add 480 mL of ethyl acetate, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 1% water / acetonitrile 500 mL to the product, add 16.8 grams of sodium bicarbonate, stir thoroughly, control the temperature at 55°C to react for 2 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB sodium butanesulfonate, weighing 36.7 grams, with a yield of 92.0% and a purity of 99.51%.

[0082] Example 12: Preparation of TMB Potassium Butanesulfonate;

[0083] Add 24.0 g of 3,3',5,5'-tetramethylbenzidine and 240 mL of dioxane to the reaction bottle. Add 31.3 g of sodium 4-bromobutane-1-sulfonate and TBAB under stirring. 6.4 grams, control the temperature at 60°C to react for 8 hours. After the reaction is completed, cool the reaction solution to room temperature; add 500 mL of 3% potassium bicarbonate aqueous solution to the reaction solution under stirring, separate the water layer, repeat the operation twice, separate the alkaline water layer, and combine the alkaline water solution for standby use; add 20% sulfuric acid aqueous solution to the alkaline water solution, stir thoroughly, adjust the pH to 6, add 450 mL of dichloromethane, stir, extract, separate, collect the organic layer, repeat the operation once, combine the organic layers, and concentrate to dryness to obtain the product; add 500 mL of 1% water / ethanol to the product, add 20.0 grams of potassium bicarbonate, stir thoroughly, control the temperature at 75°C to react for 4 hours, cool to room temperature, filter, collect the filter cake, and dry to obtain TMB butanesulfonic acid potassium, weighing 37.9 grams, with a yield of 91.5% and a purity of 99.17%.

[0084] Example 13: Comparison of water solubility of TMB alkyl sulfonic acid alkali metal salts with TMB and TMB hydrochloride;

[0085] The water solubility of the TMB alkylsulfonic acid alkali metal salt, TMB and TMB hydrochloride obtained in Examples 1 to 12 was tested at room temperature 20° C. The results are shown in Table 1 below.

[0086] Table 1 Comparison of water solubility of TMB alkylsulfonic acid alkali metal salt, TMB and TMB hydrochloride

[0087]

[0088]

[0089] It can be seen from the above embodiments that the present invention provides a TMB alkyl sulfonic acid alkali metal salt and a preparation method thereof. As can be seen from Table 1, TMB is poorly soluble in water, TMB hydrochloride is slightly soluble in water, TMB alkyl sulfonates are all soluble in water, the alkyl groups in the TMB alkyl sulfonate molecules are the same, TMB alkyl sulfonate potassium salt>TMB alkyl sulfonate sodium salt>TMB alkyl sulfonate lithium salt>TMB hydrochloride>TMB, the alkyl groups in the TMB alkyl sulfonate molecules are different, the alkali metal salts are the same, TMB methane sulfonate alkali metal salt>TMB ethane sulfonate alkali metal salt>TMB propane sulfonate alkali metal salt>TMB butane sulfonate alkali metal salt>TMB hydrochloride>TMB. It can be seen that the TMB alkyl sulfonic acid alkali metal salt of the present invention is beneficial to the application in aqueous preparations due to the increase in water solubility.

[0090] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing TMB alkyl sulfonic acid alkali metal salt, characterized in that: The following steps are involved: 1) mixing 3,3',5,5'-tetramethylbenzidine and alkali metal salt of halogenated alkylsulfonic acid in a reaction solvent, and performing an alkylation reaction under the action of a catalyst to obtain a reaction solution; 2) adding an alkaline aqueous solution to the reaction solution, mixing, separating and extracting the alkaline aqueous layer, repeating at least once, combining the alkaline aqueous layers, and obtaining an alkaline aqueous extract; 3) adding acid water to the alkaline water extract to adjust the pH, adding the extraction solution, mixing, collecting the organic layer, drying and concentrating to obtain TMB alkyl sulfonic acid; 4) TMB alkyl sulfonic acid and alkali metal bicarbonate are mixed in a salt-forming solvent to carry out a salt-forming reaction, and the reaction product is dried to obtain TMB alkyl sulfonic acid alkali metal salt.

2. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 1, characterized in that: The chemical formula of the alkali metal halide sulfonate is XR-SO3M, wherein X comprises Cl or Br, R is a C1-C10 alkyl group, and M comprises Li, Na or K.

3. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 1 or 2, characterized in that, The molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal salt of halogenated alkyl sulfonate is 1:0.9 to 1:1.5, and the reaction solvent comprises one or more of dichloromethane, chloroform, acetonitrile, ethyl acetate, tetrahydrofuran, dioxane, triethylamine and N,N-dimethylformamide; The catalyst comprises one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium hydrogen sulfate.

4. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 3, characterized in that: The molar ratio of the 3,3',5,5'-tetramethylbenzidine to the catalyst is 1:0.1 to 1:1; The mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the reaction solvent is 1g:5-30mL; The temperature of the alkylation reaction is 35 to 100° C., and the time of the alkylation reaction is 1 to 24 hours.

5. The method for preparing the TMB alkylsulfonic acid alkali metal salt according to claim 1, 2 or 4, characterized in that: The mass concentration of the alkaline aqueous solution is 1-10%, and the alkali in the alkaline aqueous solution is one or more of alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates and alkali metal acetates; The mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the alkaline aqueous solution is 1 g:5-30 mL.

6. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 5, characterized in that: In the step 3), the acid water is prepared by preparing acid and water, wherein the acid comprises one or more of hydrochloric acid, sulfuric acid and acetic acid, the volume ratio of the acid to water is 1:3 to 1:10, and the pH is adjusted to 2 to 7.

7. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 6, characterized in that: The extraction solution comprises one or more of dichloromethane, chloroform and ethyl acetate, and the mass volume ratio of the 3,3',5,5'-tetramethylbenzidine to the extraction solution is 1 g:5-30 mL.

8. The method for preparing the TMB alkylsulfonic acid alkali metal salt according to claim 1, 2, 6 or 7, characterized in that: The alkali metal bicarbonate comprises one or more of lithium bicarbonate, sodium bicarbonate and potassium bicarbonate, the salt-forming solvent comprises an organic solvent and water, the organic solvent comprises one or more of dichloromethane, chloroform, methanol, ethanol, acetone, acetonitrile, ethyl acetate, tetrahydrofuran and dioxane, and the volume percentage of the water and the organic solvent is 1-5%.

9. The method for preparing TMB alkylsulfonic acid alkali metal salt according to claim 8, characterized in that: The temperature of the salt-forming reaction is 35 to 80° C., and the time of the salt-forming reaction is 1 to 24 hours; The molar ratio of the 3,3',5,5'-tetramethylbenzidine to the alkali metal bicarbonate is 1:1 to 1:2; The usage ratio of the 3,3',5,5'-tetramethylbenzidine and the salt-forming solvent is 1g:5-30mL.

10. TMB alkylsulfonic acid alkali metal salt prepared by the preparation method according to any one of claims 1 to 9.

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