Method for preparing tetrakis hydroxymethyl phosphonium sulfate by using high-concentration hydride

Abstract

The invention discloses a method for preparing tetrakis hydroxymethyl phosphonium sulfate by using high-concentration hydride, and belongs to the technical field of preparation of tetrakis hydroxymethyl phosphonium sulfate. The method for preparing tetrakis hydroxymethyl phosphonium sulfate by using the high-concentration hydride comprises the following steps: step 1, adding concentrated sulfuric acid and formaldehyde into a reaction kettle, uniformly stirring and mixing, then adding an organic catalyst and a modified surfactant, and continuously stirring to completely and uniformly mix reactants to obtain a mixed solution; 2, hydride is introduced into a reaction kettle through a pipeline and reacts with the mixed solution, a heating reaction is conducted, after the reaction is finished, the pipeline is closed, and a reaction solution is obtained; and 3, carrying out vacuum concentration treatment on the reaction liquid, and recrystallizing to obtain tetrakis hydroxymethyl phosphonium sulfate. The tetrakis hydroxymethyl phosphonium sulfate prepared by the method has excellent yield and purity.

Description

Technical Field

[0001] The invention belongs to the technical field of tetrakis hydroxymethyl phosphonium sulfate preparation, and particularly relates to a method for preparing tetrakis hydroxymethyl phosphonium sulfate by utilizing high-concentration hydride. Background Art

[0002] Tetrakis (hydroxymethyl) phosphonium sulfate is a green and environmentally friendly quaternary phosphate fungicide with broad application prospects. It has good water solubility, low freezing point, stable chemical properties, and long-term storage does not affect its quality. Moreover, tetrakis (hydroxymethyl) phosphonium sulfate can be quickly degraded into completely harmless substances before and after use, greatly reducing the impact on the environment. Therefore, it is widely used in many industries such as water treatment, oil field pipelines, fishery farming, fabric flame retardant treatment, leather softening and papermaking. With the improvement of environmental awareness and the development of industrial automation, the demand for environmentally friendly fungicides in these industries has continued to increase, driving the expansion of the tetrakis (hydroxymethyl) phosphonium sulfate market.

[0003] The Chinese invention patent application with the publication number of CN 117680083 B discloses a preparation process and preparation device of tetrakis(hydroxymethyl)phosphonium sulfate, which includes a preparation tower; a mixing and stirring section, wherein the mixing and stirring section includes a formaldehyde inlet pipe fixedly mounted on the manufacturing tower for feeding formaldehyde solution; S1. When preparing the tetrakis(hydroxymethyl)phosphonium sulfate aqueous solution, the formaldehyde solution and the sulfuric acid solution are first injected into the preparation tower through the formaldehyde inlet pipe and the sulfuric acid inlet pipe at a molar ratio of 8:1. The advantages are: the invention can fully mix the formaldehyde solution and the sulfuric acid solution by adopting a rotating stirring method while coordinating the reciprocating swing and interlacing, and adopts a spraying and sprinkling method to make it fully contact and react with the phosphine gas under a constant temperature environment, effectively improving the contact range and contact time between the formaldehyde and sulfuric acid mixed solution and the phosphine gas, and improving the preparation efficiency, but the yield and purity of the tetrakis(hydroxymethyl)phosphonium sulfate prepared by this method still have room for improvement. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing tetrakis hydroxymethyl phosphonium sulfate by using high-concentration hydride, so as to solve the technical problems of poor purity and yield of tetrakis hydroxymethyl phosphonium sulfate in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high-concentration hydride, comprising the following steps:

[0007] Step 1: Add concentrated sulfuric acid and formaldehyde into a reaction kettle, stir and mix evenly, then add an organic catalyst and a modified surfactant, continue stirring to make the reactants completely mixed evenly, and obtain a mixed solution;

[0008] Step 2: introducing the covalent hydride into the reactor through a pipeline, reacting with the mixed liquid, heating the reaction, and after the reaction is completed, closing the pipeline to obtain a reaction liquid;

[0009] Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate.

[0010] Preferably, in the step 1, the molar ratio of concentrated sulfuric acid to formaldehyde is (1-1.7): (7.8-13.4), the volume fraction of concentrated sulfuric acid is 96vt%, the volume fraction of formaldehyde is 96vt%, the mixing time is 2-4h, the amount ratio of concentrated sulfuric acid, organic catalyst and modified surfactant is (10-17)g: (0.55-0.8)g: (0.3-0.5)g, and the stirring time is continued for 30-45min.

[0011] Preferably, the method for preparing the organic catalyst comprises the following steps:

[0012] Q1: Add cyanuric chloride to a container containing acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time add sodium azide to a container containing deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react, extract after the reaction is completed, remove the lower organic phase for washing, combine the organic phases, wash, dry, filter, and rotary evaporate to obtain a white powder;

[0013] Q2: In a nitrogen environment, pyrrolidine and tetrahydrofuran are added to a container, and after stirring and mixing, phosphorus trichloride is slowly added under a low temperature environment. After the addition is completed, the temperature is naturally raised to room temperature for reaction. After the reaction is completed, the reaction liquid is filtered, and the filtered powder is mixed and stirred with tetrahydrofuran, and then filtered again. The filtrate is combined, filtered, heated and distilled under reduced pressure to obtain a white liquid;

[0014] Q3: Add white liquid into a container, then add toluene, stir the mixed solution to obtain mixture 1, then add white powder into toluene, stir and dissolve to obtain mixture 2, slowly drop mixture 1 into mixture 2 in an ice water bath, after the addition is completed, reduce the pressure, heat to react, after the reaction is completed, cool, filter, wash, filter, and obtain an organic catalyst.

[0015] In the above process, the synthesis reaction formula of the organic catalyst is as follows:

[0016]

[0017] The results of mass spectrometry analysis of the white powder are: m / z: 204.04 (100.0%), 205.03 (4.4%), 205.04 (3.2%); the results of mass spectrometry analysis of the white liquid are: m / z: 241.17 (100.0%), 242.17 (14.1%); the results of mass spectrometry analysis of the organic catalyst are: m / z: 843.53 (100.0%), 844.53 (47.7%), 845.54 (9.0%), 845.53 (2.4%), 846.54 (1.2%).

[0018] Preferably, in Q1, the dosage ratio of cyanuric chloride, acetone, sodium azide and deionized water is (2-4) g: (50-100) mL: (2.1-4.1) g: (80-160) mL, the reaction time is 6-8 h, dichloromethane is added for extraction, washed with dichloromethane, then washed with saturated sodium chloride solution, and dried with anhydrous magnesium sulfate.

[0019] Preferably, in Q2, the dosage ratio of pyrrolidine, tetrahydrofuran and phosphorus trichloride is (19-38) mL: (40-80) mL: (5-8) mL, the low temperature is -76 to -80°C, the dropping time is 1-2 h, the reaction time is 10-12 h, and the heating and reduced pressure distillation temperature is 120-150°C; in Q3, the mass ratio of white liquid to white powder is (3.65-7.3): (1-1.9), the ice water bath temperature is 0-3°C, the dropping time is 30-45 min, the heating reaction temperature is 100-110°C, the time is 45-50 h, and washing is carried out with n-hexane.

[0020] Preferably, the preparation method of the modified surfactant comprises the following steps:

[0021] S1: Add cesium carbonate and 3-methyl-4-isopropylphenol to a container containing acetone, stir and reflux, add 1,6-dibromohexane after reflux, heat and continue the reaction, and after the reaction is completed, reduce pressure and filter, distill under reduced pressure, purify, and vacuum dry to obtain intermediate product 1;

[0022] S2: adding the intermediate product 1 and anhydrous potassium carbonate into a container containing a mixed solution of dimethylamine and tetrahydrofuran, heating and stirring, and after the stirring is completed, filtering, rotary evaporation, purification, and vacuum drying to obtain the intermediate product 2;

[0023] S3: Add the intermediate product 2 and ethyl 4-bromobutyrate to a container containing acetonitrile, heat and stir to react, after the reaction is completed, distill under reduced pressure, vacuum dry, then add sodium hydroxide, stir to react, after the reaction is completed, filter, wash, dry, wash, centrifuge, vacuum dry to obtain a modified surfactant.

[0024] In the above process, the synthetic reaction formula of the modified surfactant is as follows:

[0025]

[0026] The results of mass spectrometry analysis of intermediate product 1 are: m / z: 312.11 (100.0%), 314.11 (97.5%), 313.11 (17.3%), 315.11 (17.2%), 316.11 (1.6%), 314.12 (1.5%); the results of mass spectrometry analysis of intermediate product 2 are: m / z: 277.24 (100.0%), 278.24 (19.9%), 279.25 (1.9%); the results of mass spectrometry analysis of modified surfactants are: m / z: 363.28 (100.0%), 364.28 (24.3%), 365.28 (3.4%).

[0027] Preferably, in S1, the molar ratio of cesium carbonate, 3-methyl-4-isopropylphenol and 1,6-dibromohexane is (5.74-6.89):(2.87-3.44):(14.36-17.23), the stirring reflux speed is 700-800 rpm, the reflux time is 1-2 h, the heating continuous stirring temperature is 60-70 ° C, the time is 4-6 h, and the purification is carried out using a mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 as the eluent.

[0028] Preferably, in S2, the dosage ratio of the intermediate product 1, anhydrous potassium carbonate, dimethylamine and tetrahydrofuran is (0.2-0.4) g: (0.6-1.2) g: (0.53-1.06) mL: (4.47-8.94) mL, the heating and stirring temperature is 70-80°C, the rotation speed is 700-800 rpm, the time is 10-15h, and the purification is carried out using a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent.

[0029] Preferably, in S3, the dosage ratio of the intermediate product 2,4-bromobutyric acid ethyl ester, acetonitrile and sodium hydroxide is (0.24-0.48) g: (0.24-0.48) g: (6-12) mL: (7-14) mL, the heating and stirring reaction temperature is 70-80°C, the stirring speed is 700-800 rpm, the time is 24-28h, the concentration of sodium hydroxide is 0.1mmol / L, the stirring reaction speed is 600-700rpm, the time is 1-2h, and the reaction is washed with ultrapure water, dried, and then washed with ethyl acetate.

[0030] Preferably, in step 2, the covalent hydride is phosphine, the ratio of phosphine to the mixed solution is (7-10) g: (20-25) mL, the heating reaction temperature is 50-60° C., and the reaction time is 10-14 h.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. The present invention uses concentrated sulfuric acid, formaldehyde and hydride as raw materials to prepare tetrakis(hydroxymethyl)phosphonium sulfate. During the preparation process, an organic catalyst prepared from cyanuric chloride, sodium azide, pyrrolidine and phosphorus trichloride as raw materials is added, and a modified surfactant prepared from 3-methyl-4-isopropylphenol, 1,6-dibromohexane, dimethylamine and ethyl 4-bromobutyrate as raw materials is also added. By adding the organic catalyst and the modified surfactant to the preparation process, the purity and yield of tetrakis(hydroxymethyl)phosphonium sulfate can be effectively improved.

[0033] 2. The present invention uses cyanuric chloride, sodium azide, pyrrolidine and phosphorus trichloride as raw materials to prepare an organic catalyst, and uses the substance as a catalyst in the preparation process of tetrakis(hydroxymethyl)phosphonium sulfate, which can effectively improve its production efficiency and yield. The nitrogen-phosphorus bond contained in the organic catalyst enables the organic catalyst to have a higher electron density and a more flexible electron transfer ability, and it is easier to exchange electrons and convert energy with reactant molecules, which helps to reduce the activation energy of the reaction and improve the reaction rate and yield; the spatial configuration of the pyrrole ring and the nitrogen heterocycle contained in the organic catalyst enables the catalyst to have a higher affinity and selectivity for the target reactant molecules, and can form stable chemical bonds and complexes with the radicals in the reactant molecules to prevent the occurrence of side reactions; and the chemical bonds in the organic catalyst have excellent stability and are not easily destroyed or deactivated during the reaction, thereby extending the service life of the organic catalyst and reducing the frequency and cost of replacing it.

[0034] 3. The present invention uses 3-methyl-4-isopropylphenol, 1,6-dibromohexane, dimethylamine and ethyl 4-bromobutyrate as raw materials to prepare a modified surfactant. The hydrophilic group and the hydrophobic group contained in the modified surfactant can form micelles or interface layers in the solution, change the surface properties and interfacial tension of the solution, and in the preparation process of tetrakis(hydroxymethyl)phosphonium sulfate, the modified surfactant can react with the reactant molecules through the hydrophilic group to promote the dissolution and dispersion of the reactants. At the same time, the hydrophobic group can help to form a stable product structure, thereby improving the reaction rate and preparation efficiency; and the modified surfactant formed by covalent bonding has a stable structure and is not easily affected by external factors and decomposed or deteriorated, which helps to maintain the effectiveness of the modified surfactant in the preparation process and ensure the stability and quality of the tetrakis(hydroxymethyl)phosphonium sulfate product. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1: This example discloses a method for preparing an organic catalyst, comprising the following steps:

[0037] Q1: Add 3g of cyanuric chloride to a container containing 75mL of acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time, add 3.1g of sodium azide to a container containing 120mL of deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react for 8h, and after the reaction is completed, add dichloromethane for extraction, take the lower organic phase, wash it with dichloromethane, combine the organic phases, wash it with a saturated sodium chloride solution, dry it with anhydrous magnesium sulfate, filter it, and rotary evaporate it to obtain a white powder;

[0038] Q2: In a nitrogen environment, add 28.5 mL of pyrrolidine and 60 mL of tetrahydrofuran to the container, stir and mix evenly, then slowly add 6.5 mL of phosphorus trichloride at -78 °C for 1 hour. After the addition is completed, naturally warm up to room temperature and react for 12 hours. After the reaction is completed, filter the reaction solution, mix and stir the filtered powder with tetrahydrofuran, and then filter again. Combine the filtrate, filter with suction, and heat at 140 °C for reduced pressure distillation to obtain a white liquid.

[0039] Q3: Add 5.5 mL of white liquid into a container, then add 20 mL of toluene, stir the mixed solution to obtain mixture 1, then add 1.45 g of white powder into 30 mL of toluene, stir and dissolve to obtain mixture 2, slowly add mixture 1 dropwise into mixture 2 in a 0°C ice-water bath environment, the dropping time is 35 min, after the dropping is completed, reduce the pressure, heat at 110°C to react for 48 h, after the reaction is completed, cool, filter, wash with n-hexane, filter, and obtain an organic catalyst.

[0040] This embodiment discloses a method for preparing a modified surfactant, comprising the following steps:

[0041] S1: 2.89 g of cesium carbonate and 1.1 g of 3-methyl-4-isopropylphenol were added to a container containing 60 mL of acetone, and the mixture was stirred and refluxed at 800 rpm for 2 h. After the reflux, 8.95 g of 1,6-dibromohexane was added, and the mixture was heated at 70° C. and reacted for 6 h. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. A mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 was used as the eluent for purification, and vacuum drying was performed to obtain an intermediate product 1;

[0042] S2: 0.3 g of intermediate product 1 and 0.9 g of anhydrous potassium carbonate were added to a container containing a mixed solution of 0.79 mL of dimethylamine and 6.65 mL of tetrahydrofuran, heated and stirred at 80°C and 800 rpm for 12 h. After the stirring was completed, the mixture was filtered and rotary evaporated, and purified with a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent, and vacuum dried to obtain intermediate product 2;

[0043] S3: Add 0.36 g of intermediate product 2 and 0.36 g of ethyl 4-bromobutyrate to a container containing 9 mL of acetonitrile, heat and stir at 80°C and 800 rpm for 24 h, and after the reaction is completed, distill under reduced pressure and dry in vacuo. Then, add 10.5 mL of 0.1 mmol / L sodium hydroxide, stir at 700 rpm for 2 h, and after the reaction is completed, filter, wash with ultrapure water, dry, wash with ethyl acetate, centrifuge, and dry in vacuo to obtain a modified surfactant.

[0044] This embodiment discloses a method for preparing tetrakis(hydroxymethyl)phosphonium sulfate using high-concentration hydride, comprising the following steps:

[0045] Step 1: Add 13.5 g of 96 vt% concentrated sulfuric acid and 32 g of 96 vt% formaldehyde into a reactor, stir and mix for 4 h, then add 0.73 g of an organic catalyst and 0.4 g of a modified surfactant, and continue stirring for 45 min to mix the reactants completely and evenly to obtain a mixed solution;

[0046] Step 2: 8.5 g of phosphine was introduced into the reactor through a pipeline to react with 22.5 mL of the mixed solution, and the mixture was heated at 60° C. for 12 h. After the reaction was completed, the pipeline was closed to obtain a reaction solution;

[0047] Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate.

[0048] Example 2: This example discloses a method for preparing an organic catalyst, comprising the following steps:

[0049] Q1: Add 4g of cyanuric chloride to a container containing 50mL of acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time, add 2.1g of sodium azide to a container containing 80mL of deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react for 8h, and after the reaction is completed, add dichloromethane for extraction, take the lower organic phase, wash it with dichloromethane, combine the organic phases, wash it with a saturated sodium chloride solution, dry it with anhydrous magnesium sulfate, filter it, and rotary evaporate it to obtain a white powder;

[0050] Q2: In a nitrogen environment, add 19 mL of pyrrolidine and 40 mL of tetrahydrofuran to a container, stir and mix evenly, then slowly add 8 mL of phosphorus trichloride at -78 °C for 1 h. After the addition is complete, naturally warm up to room temperature and react for 12 h. After the reaction is complete, filter the reaction solution, mix and stir the filtered powder with tetrahydrofuran, and then filter again. Combine the filtrates, filter with suction, and heat at 140 °C for reduced pressure distillation to obtain a white liquid.

[0051] Q3: Add 3.65 mL of white liquid into a container, then add 20 mL of toluene, stir the mixed solution to obtain mixture 1, then add 1.9 g of white powder into 30 mL of toluene, stir and dissolve to obtain mixture 2, slowly add mixture 1 dropwise into mixture 2 in a 0°C ice water bath environment, the dropping time is 35 min, after the dropping is completed, reduce the pressure, heat at 110°C to react for 48 h, after the reaction is completed, cool, filter, wash with n-hexane, filter, and obtain an organic catalyst.

[0052] This embodiment discloses a method for preparing a modified surfactant, comprising the following steps:

[0053] S1: 3.15 g of cesium carbonate and 1 g of 3-methyl-4-isopropylphenol were added to a container containing 60 mL of acetone, and the mixture was stirred and refluxed at 800 rpm for 2 h. After the reflux, 9.76 g of 1,6-dibromohexane was added, and the mixture was heated at 70° C. and reacted for 6 h. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. A mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 was used as the eluent for purification, and vacuum drying was performed to obtain an intermediate product 1;

[0054] S2: 0.2 g of intermediate product 1 and 1.2 g of anhydrous potassium carbonate were added to a container containing a mixed solution of 0.53 mL of dimethylamine and 4.47 mL of tetrahydrofuran, heated and stirred at 80°C and 800 rpm for 12 h. After the stirring was completed, the mixture was filtered and rotary evaporated, and purified with a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent, and vacuum dried to obtain intermediate product 2;

[0055] S3: Add 0.24 g of intermediate product 2 and 0.48 g of ethyl 4-bromobutyrate to a container containing 12 mL of acetonitrile, heat and stir at 80°C and 800 rpm for 24 h. After the reaction is completed, distill under reduced pressure and dry in vacuo. Then, add 14 mL of 0.1 mmol / L sodium hydroxide and stir at 700 rpm for 2 h. After the reaction is completed, filter, wash with ultrapure water, dry, wash with ethyl acetate, centrifuge, and dry in vacuo to obtain a modified surfactant.

[0056] This embodiment discloses a method for preparing tetrakis(hydroxymethyl)phosphonium sulfate using high-concentration hydride, comprising the following steps:

[0057] Step 1: Add 17 g of 96 vt% concentrated sulfuric acid and 23.8 g of 96 vt% formaldehyde into a reactor, stir and mix for 4 h, then add 0.55 g of an organic catalyst and 0.5 g of a modified surfactant, and continue stirring for 45 min to mix the reactants completely and evenly to obtain a mixed solution;

[0058] Step 2: Introduce 7 g of phosphine into the reactor through a pipeline, react with 20 mL of the mixed solution, heat at 60° C. for 12 h, and after the reaction is completed, close the pipeline to obtain a reaction solution;

[0059] Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate.

[0060] Example 3: This example discloses a method for preparing an organic catalyst, comprising the following steps:

[0061] Q1: Add 2g of cyanuric chloride to a container containing 100mL of acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time, add 4.1g of sodium azide to a container containing 160mL of deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react for 8h, and after the reaction is completed, add dichloromethane for extraction, take the lower organic phase, wash it with dichloromethane, combine the organic phases, wash it with a saturated sodium chloride solution, dry it with anhydrous magnesium sulfate, filter it, and rotary evaporate it to obtain a white powder;

[0062] Q2: In a nitrogen environment, add 38 mL of pyrrolidine and 80 mL of tetrahydrofuran to a container, stir and mix evenly, then slowly add 5 mL of phosphorus trichloride at -78 °C for 1 h. After the addition is complete, naturally warm up to room temperature and react for 12 h. After the reaction is complete, filter the reaction solution, mix and stir the filtered powder with tetrahydrofuran, and then filter again. Combine the filtrate, filter with suction, and heat at 140 °C for reduced pressure distillation to obtain a white liquid.

[0063] Q3: Add 7.3 mL of white liquid into a container, then add 20 mL of toluene, stir the mixed solution to obtain mixture 1, then add 1 g of white powder into 30 mL of toluene, stir and dissolve to obtain mixture 2, slowly add mixture 1 dropwise into mixture 2 in a 0°C ice-water bath environment, the dropping time is 35 min, after the dropping is completed, reduce the pressure, heat at 110°C to react for 48 h, after the reaction is completed, cool, filter, wash with n-hexane, filter, and obtain an organic catalyst.

[0064] This embodiment discloses a method for preparing a modified surfactant, comprising the following steps:

[0065] S1: 2.63 g of cesium carbonate and 1.2 g of 3-methyl-4-isopropylphenol were added to a container containing 60 mL of acetone, and the mixture was stirred and refluxed at 800 rpm for 2 h. After the reflux, 8.14 g of 1,6-dibromohexane was added, and the mixture was heated at 70° C. and reacted for 6 h. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. A mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 was used as the eluent for purification, and vacuum drying was performed to obtain an intermediate product 1;

[0066] S2: 0.4 g of intermediate product 1 and 0.6 g of anhydrous potassium carbonate were added to a container containing a mixed solution of 1.06 mL of dimethylamine and 8.94 mL of tetrahydrofuran, heated and stirred at 80°C and 800 rpm for 12 h. After the stirring was completed, the mixture was filtered and rotary evaporated, and purified with a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent, and vacuum dried to obtain intermediate product 2;

[0067] S3: Add 0.48g of intermediate product 2 and 0.24g of ethyl 4-bromobutyrate to a container containing 6mL of acetonitrile, heat and stir at 80°C and 800rpm for 24h. After the reaction, distill under reduced pressure and dry in vacuum. Then, add 7mL of 0.1mmol / L sodium hydroxide and stir at 700rpm for 2h. After the reaction, filter, wash with ultrapure water, dry, wash with ethyl acetate, centrifuge, and dry in vacuum to obtain a modified surfactant.

[0068] This embodiment discloses a method for preparing tetrakis(hydroxymethyl)phosphonium sulfate using high-concentration hydride, comprising the following steps:

[0069] Step 1: add 10g of concentrated sulfuric acid with a volume fraction of 96vt% and 41g of formaldehyde with a volume fraction of 96vt% into a reactor, stir and mix for 4h, then add 0.8g of an organic catalyst and 0.3g of a modified surfactant, and continue stirring for 45min to make the reactants completely mixed to obtain a mixed solution;

[0070] Step 2: Introduce 10 g of phosphine into the reactor through a pipeline, react with 25 mL of the mixed solution, heat at 60° C. for 12 h, and after the reaction is completed, close the pipeline to obtain a reaction solution;

[0071] Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate.

[0072] Example 4: This example discloses a method for preparing an organic catalyst, comprising the following steps:

[0073] Q1: Add 2.5 g of cyanuric chloride to a container containing 80 mL of acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time add 2.8 g of sodium azide to a container containing 100 mL of deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react for 8 hours, and after the reaction is completed, add dichloromethane for extraction, take the lower organic phase, wash it with dichloromethane, combine the organic phases, wash it with a saturated sodium chloride solution, dry it with anhydrous magnesium sulfate, filter it, and rotary evaporate it to obtain a white powder;

[0074] Q2: In a nitrogen environment, add 22 mL of pyrrolidine and 45 mL of tetrahydrofuran to a container, stir and mix evenly, then slowly add 6 mL of phosphorus trichloride at -78 °C for 1 h. After the addition is complete, naturally warm up to room temperature and react for 12 h. After the reaction is complete, filter the reaction solution, mix and stir the filtered powder with tetrahydrofuran, and then filter again. Combine the filtrates, filter with suction, and heat at 140 °C for reduced pressure distillation to obtain a white liquid.

[0075] Q3: Add 6.12 mL of white liquid into a container, then add 20 mL of toluene, stir the mixed solution to obtain mixture 1, then add 1.2 g of white powder into 30 mL of toluene, stir and dissolve to obtain mixture 2, slowly add mixture 1 dropwise into mixture 2 in a 0°C ice-water bath environment, the dropping time is 35 min, after the dropping is completed, reduce the pressure, heat at 110°C to react for 48 h, after the reaction is completed, cool, filter, wash with n-hexane, filter, and obtain an organic catalyst.

[0076] This embodiment discloses a method for preparing a modified surfactant, comprising the following steps:

[0077] S1: 2.77 g of cesium carbonate and 1.05 g of 3-methyl-4-isopropylphenol were added to a container containing 60 mL of acetone, and the mixture was stirred and refluxed at 800 rpm for 2 h. After the reflux, 8.53 g of 1,6-dibromohexane was added, and the mixture was heated at 70° C. and reacted for 6 h. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. A mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 was used as the eluent for purification, and vacuum drying was performed to obtain an intermediate product 1;

[0078] S2: 0.25 g of intermediate product 1 and 0.7 g of anhydrous potassium carbonate were added to a container containing a mixed solution of 0.68 mL of dimethylamine and 5.12 mL of tetrahydrofuran, and heated and stirred at 80°C and 800 rpm for 12 h. After the stirring was completed, the mixture was filtered and rotary evaporated, and purified with a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent, and vacuum dried to obtain intermediate product 2;

[0079] S3: Add 0.25g of intermediate product 2 and 0.27g of ethyl 4-bromobutyrate to a container containing 7mL of acetonitrile, heat and stir at 80°C and 800rpm for 24h. After the reaction, distill under reduced pressure and dry in vacuum. Then, add 9mL of sodium hydroxide with a concentration of 0.1mmol / L, stir at 700rpm for 2h. After the reaction, filter, wash with ultrapure water, dry, wash with ethyl acetate, centrifuge, and dry in vacuum to obtain a modified surfactant.

[0080] This embodiment discloses a method for preparing tetrakis(hydroxymethyl)phosphonium sulfate using high-concentration hydride, comprising the following steps:

[0081] Step 1: Add 11 g of 96 vt% concentrated sulfuric acid and 25.7 g of 96 vt% formaldehyde into a reactor, stir and mix for 4 h, then add 0.67 g of an organic catalyst and 0.35 g of a modified surfactant, and continue stirring for 45 min to mix the reactants completely and evenly to obtain a mixed solution;

[0082] Step 2: Introduce 9 g of phosphine into the reactor through a pipeline, react with 21 mL of the mixed solution, heat at 60° C. for 12 h, and after the reaction is completed, close the pipeline to obtain a reaction solution;

[0083] Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate.

[0084] Comparative Example 1: Compared with Example 1, in the preparation process of the organic catalyst in Comparative Example 1, no cyanuric chloride was added, and other conditions remained unchanged.

[0085] Comparative Example 2: Compared with Example 1, in Comparative Example 2, during the preparation of the modified surfactant, no 3-methyl-4-isopropyl phenol was added, and other conditions remained unchanged.

[0086] Comparative Example 3: Compared with Example 1, in Comparative Example 3, during the preparation of tetrakis(hydroxymethyl)phosphonium sulfate, no organic catalyst was added, and other conditions remained unchanged.

[0087] Comparative Example 4: Compared with Example 1, in Comparative Example 4, during the preparation of tetrakis(hydroxymethyl)phosphonium sulfate, no modified surfactant was added, and other conditions remained unchanged.

[0088] Experimental example: The mass fraction of tetrakis(hydroxymethyl)phosphonium sulfate is determined by iodine titration. Tetrakis(hydroxymethyl)phosphonium sulfate and iodine have a stoichiometric relationship. The reaction equation between the two is as follows: (CH2OH)4P2SO4+I2+NaHCO3→(CH2OH)3PO+Na2SO4+CO2+H2O. The obtained product is weighed and placed in an iodine volumetric bottle. 1% soluble starch indicator is added. The product is titrated with iodine standard solution until the solution shows blue as the midpoint. The volume of iodine standard solution consumed is recorded. According to the formula: The mass fraction of tetrakis(hydroxymethyl)phosphonium sulfate (%) = {[C I2 ·(V1-V2)·406] / 1000×m 样品}×100%, where C I2 is the concentration of the iodine standard solution, V1 is the volume of the iodine standard solution consumed by the sample titration, V2 is the volume of the iodine standard solution consumed by the blank titration, m 样品 is the mass of the sample, and according to the yield (%) = (m 产量 / m 理论值 )×100%, the test results are shown in Table 1:

[0089] Table 1

[0090] project Yield / % Mass fraction / % Example 1 84.65 94.17 Example 2 84.47 94.12 Example 3 84.52 93.88 Example 4 84.03 93.83 Comparative Example 1 80.58 90.27 Comparative Example 2 80.23 90.24 Comparative Example 3 78.47 89.48 Comparative Example 4 78.21 89.23

[0091] It can be seen from the test results in Table 1 that the tetrakis hydroxymethyl phosphonium sulfate obtained by the methods of Examples 1-4 can have excellent yield and purity, wherein the mass fraction result can be expressed as the purity of the product. Comparison between Comparative Example 1 and Examples 1-4 shows that the addition of cyanuric chloride can improve the yield and purity of tetrakis hydroxymethyl phosphonium sulfate; comparison between Comparative Example 2 and Examples 1-4 shows that the addition of 3-methyl-4-isopropylphenol can improve the yield and purity of tetrakis hydroxymethyl phosphonium sulfate; comparison between Comparative Example 3 and Examples 1-4 shows that the addition of an organic catalyst can improve the yield and purity of tetrakis hydroxymethyl phosphonium sulfate; comparison between Comparative Example 4 and Examples 1-4 shows that the addition of a modified surfactant can improve the yield and purity of tetrakis hydroxymethyl phosphonium sulfate.

[0092] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0093] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing tetrakis(hydroxymethyl)phosphonium sulfate using high concentration hydride, characterized in that: The following steps are involved: Step 1: Add concentrated sulfuric acid and formaldehyde into a reaction kettle, stir and mix evenly, then add an organic catalyst and a modified surfactant, continue stirring to make the reactants completely mixed evenly, and obtain a mixed solution; Step 2: introducing the covalent hydride into the reactor through a pipeline to react with the mixed liquid, heating the reaction, and after the reaction is completed, closing the pipeline to obtain a reaction liquid; Step 3: The reaction solution is concentrated under reduced pressure and recrystallized to obtain tetrakishydroxymethylphosphonium sulfate; In the step 1, the structural formula of the organic catalyst is as follows: The structural formula of the modified surfactant is as follows:

2. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 1, characterized in that: In the step 1, the molar ratio of concentrated sulfuric acid to formaldehyde is (1-1.7): (7.8-13.4), the volume fraction of concentrated sulfuric acid is 96vt%, the volume fraction of formaldehyde is 96vt%, the mixing time is 2-4h, the amount ratio of concentrated sulfuric acid, organic catalyst and modified surfactant is (10-17)g: (0.55-0.8)g: (0.3-0.5)g, and the stirring time is continued for 30-45min.

3. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 1, characterized in that: The method for preparing the organic catalyst comprises the following steps: Q1: Add cyanuric chloride to a container containing acetone, stir and dissolve to obtain a cyanuric chloride solution, and at the same time add sodium azide to a container containing deionized water, stir and dissolve to obtain a sodium azide solution, slowly add the sodium azide solution to the cyanuric chloride solution, react, extract after the reaction is completed, remove the lower organic phase for washing, combine the organic phases, wash, dry, filter, and rotary evaporate to obtain a white powder; Q2: In a nitrogen environment, pyrrolidine and tetrahydrofuran are added to a container, and after stirring and mixing, phosphorus trichloride is slowly added under a low temperature environment. After the addition is completed, the temperature is naturally raised to room temperature for reaction. After the reaction is completed, the reaction liquid is filtered, and the filtered powder is mixed and stirred with tetrahydrofuran, and then filtered again. The filtrate is combined, filtered, heated and distilled under reduced pressure to obtain a white liquid; Q3: Add white liquid into a container, then add toluene, stir the mixed solution to obtain mixture 1, then add white powder into toluene, stir and dissolve to obtain mixture 2, slowly drop mixture 1 into mixture 2 in an ice water bath, after the addition is completed, reduce the pressure, heat to react, after the reaction is completed, cool, filter, wash, filter, and obtain an organic catalyst.

4. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 3, characterized in that: In the Q1, the dosage ratio of cyanuric chloride, acetone, sodium azide and deionized water is (2-4) g: (50-100) mL: (2.1-4.1) g: (80-160) mL, the reaction time is 6-8 h, dichloromethane is added for extraction, washed with dichloromethane, then washed with saturated sodium chloride solution, and dried with anhydrous magnesium sulfate.

5. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 3, characterized in that: In the Q2, the dosage ratio of pyrrolidine, tetrahydrofuran and phosphorus trichloride is (19-38) mL: (40-80) mL: (5-8) mL, the low temperature is -76 to -80°C, the dropping time is 1-2 h, the reaction time is 10-12 h, and the heating and reduced pressure distillation temperature is 120-150°C; in the Q3, the mass ratio of white liquid to white powder is (3.65-7.3): (1-1.9), the ice water bath temperature is 0-3°C, the dropping time is 30-45 min, the heating reaction temperature is 100-110°C, the time is 45-50 h, and washing is carried out with n-hexane.

6. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 1, characterized in that: The preparation method of the modified surfactant comprises the following steps: S1: Add cesium carbonate and 3-methyl-4-isopropylphenol to a container containing acetone, stir and reflux, add 1,6-dibromohexane after reflux, heat and continue the reaction, and after the reaction is completed, reduce pressure and filter, distill under reduced pressure, purify, and vacuum dry to obtain intermediate product 1; S2: adding the intermediate product 1 and anhydrous potassium carbonate into a container containing a mixed solution of dimethylamine and tetrahydrofuran, heating and stirring, and after the stirring is completed, filtering, rotary evaporation, purification, and vacuum drying to obtain the intermediate product 2; S3: Add the intermediate product 2 and ethyl 4-bromobutyrate to a container containing acetonitrile, heat and stir to react, after the reaction is completed, distill under reduced pressure, vacuum dry, then add sodium hydroxide, stir to react, after the reaction is completed, filter, wash, dry, wash, centrifuge, vacuum dry to obtain a modified surfactant.

7. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 6, characterized in that: In the S1, the molar ratio of cesium carbonate, 3-methyl-4-isopropylphenol and 1,6-dibromohexane is (5.74-6.89): (2.87-3.44): (14.36-17.23), the stirring reflux speed is 700-800 rpm, the reflux time is 1-2 h, the heating continuous stirring temperature is 60-70 ° C, the time is 4-6 h, and the purification is carried out using a mixed solution of ethyl acetate and n-hexane in a volume ratio of 1:40 as the eluent.

8. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 6, characterized in that: In the S2, the dosage ratio of the intermediate product 1, anhydrous potassium carbonate, dimethylamine and tetrahydrofuran is (0.2-0.4) g: (0.6-1.2) g: (0.53-1.06) mL: (4.47-8.94) mL, the heating and stirring temperature is 70-80°C, the rotation speed is 700-800 rpm, the time is 10-15 h, and the purification is carried out using a mixed solution of ethyl acetate, methanol and triethylamine in a volume ratio of 15:1:0.7 as the eluent.

9. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 6, characterized in that: In the S3, the dosage ratio of the intermediate product 2,4-bromobutyric acid ethyl ester, acetonitrile and sodium hydroxide is (0.24-0.48) g: (0.24-0.48) g: (6-12) mL: (7-14) mL, the heating and stirring reaction temperature is 70-80°C, the stirring speed is 700-800 rpm, the time is 24-28 h, the concentration of sodium hydroxide is 0.1 mmol / L, the stirring reaction speed is 600-700 rpm, the time is 1-2 h, and the reaction is washed with ultrapure water, dried, and then washed with ethyl acetate.

10. The method for preparing tetrakis(hydroxymethyl)phosphonium sulfate by using high concentration hydride according to claim 1, characterized in that: In the step 2, the covalent hydride is phosphine, the dosage ratio of phosphine to the mixed solution is (7-10) g: (20-25) mL, the heating reaction temperature is 50-60° C., and the reaction time is 10-14 h.

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