SOLVENT MEDIUM FOR DIAZOTIZATION REACTION

Abstract

A solvent medium for diazotization reaction includes a mixed solution of polyethylene glycol and water. The molecular weight of polyethylene glycol is 200-600, and the volume ratio of polyethylene glycol and water is 1:0.4-1.5. The mixed solution also includes hydrochloric acid or sulfuric acid, and the concentration of H.sup.+ in the mixed solution is 0.32-1.72 mol L.sup.1.

Claims

1. A solvent medium for diazotization reaction, comprising a mixed solution of polyethylene glycol and water, wherein the molecular weight of polyethylene glycol is 200-600, and the volume ratio of polyethylene glycol and water is 1:0.4-1.5.

2. The solvent medium for diazotization reaction as claimed in claim 1, wherein the molecular weight of polyethylene glycol is 200-400, and the volume ratio of polyethylene glycol and water is 1:0.4-1.25.

3. The solvent medium for diazotization reaction as claimed in claim 1, wherein the molecular weight of polyethylene glycol is 400-600, and the volume ratio of polyethylene glycol and water is 1:1.0-1.5.

4. The solvent medium for diazotization reaction as claimed in claim 1, wherein the mixed solution also includes hydrochloric acid or sulfuric acid, and the concentration of H.sup.+ in the mixed solution is 0.32-1.72 mol L.sup.1.

5. The solvent medium for diazotization reaction as claimed in claim 4, wherein the concentration of H.sup.+ in the mixed solution is 0.35-1.72 mol L.sup.1.

6. The solvent medium for diazotization reaction as claimed in claim 4, wherein the concentration of H.sup.+ in the mixed solution is 0.32-0.39 mol L.sup.1.

7. The solvent medium for diazotization reaction as claimed in claim 2, wherein the mixed solution also includes hydrochloric acid or sulfuric acid, and the concentration of H.sup.+ in the mixed solution is 0.32-1.72 mol L.sup.1.

8. The solvent medium for diazotization reaction as claimed in claim 7, wherein the concentration of H.sup.+ in the mixed solution is 0.35-1.72 mol L.sup.1.

9. The solvent medium for diazotization reaction as claimed in claim 7, wherein the concentration of H.sup.+ in the mixed solution is 0.32-0.39 mol L.sup.1.

10. The solvent medium for diazotization reaction as claimed in claim 3, wherein the mixed solution also includes hydrochloric acid or sulfuric acid, and the concentration of H.sup.+ in the mixed solution is 0.32-1.72 mol L.sup.1.

11. The solvent medium for diazotization reaction as claimed in claim 10, wherein the concentration of H.sup.+ in the mixed solution is 0.35-1.72 mol L.sup.1.

12. The solvent medium for diazotization reaction as claimed in claim 10, wherein the concentration of H.sup.+ in the mixed solution is 0.32-0.39 mol L.sup.1.

Description

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The invention will be further illustrated in more detail with reference to embodiments. It is noted that, the following embodiments only are intended for the purpose of illustration and are not intended to limit the scope of the invention.

[0016] The solvent medium for diazotization reaction of the invention comprises a mixed solution of polyethylene glycol and water, the molecular weight of polyethylene glycol is 200-600, and the volume ratio of polyethylene glycol and water is 1:0.4-1.5.

[0017] Preferably, the molecular weight of polyethylene glycol is 200-400, and the volume ratio of polyethylene glycol and water is 1:0.4-1.25.

[0018] Preferably, the molecular weight of polyethylene glycol is 400-600, and the volume ratio of polyethylene glycol and water is 1:1.0-1.5.

[0019] Preferably, the mixed solution also includes hydrochloric acid or sulfuric acid, so that the H.sup.+ concentration of the mixed solution is 0.32-1.72 mol L .sup.1.

[0020] More preferably, the H.sup.+ concentration of the mixed solution is 0.35-1.72 mol L.sup.1.

[0021] More preferably, the H.sup.+ concentration of the mixed solution is 0.32-0.39 mol L.sup.1.

[0022] The solvent medium for diazotization reaction of the present invention utilizes a mixed solution of polyethylene glycol and water, the molecular weight of polyethylene glycol is 200-600, and the volume ratio of polyethylene glycol and water is 1:0.4-1.5. Experiments show that, polyethylene glycol with a molecular weight of 200-600 has significant phase transfer catalysis, and can effectively reduce the diazotization reaction time to accelerate the process of the diazotization reaction. The solvent medium also can effectively prevent the formation of a diazoamino compound and maintain the stability of a diazonium salt, thereby improving the yield of the diazonium salt and ensure the good quality of the diazonium salt. Furthermore, by means of the solvent medium, the diazotization reaction can utilize a simple operation process and a low-cost production device. The polyethylene glycol component in solvent medium is less volatile, non-irritant, non-toxic ecologically, has good solubility and dispersion properties, and can dissolve and disperse the weak alkaline and insoluble diazo components well, and thus can effectively achieve the dissolution effects of reactants in concentrated acids such as concentrated sulfuric acid. This will avoid the addition of large amount of the high concentration and large amount of acid in diazotization reaction of prior art. Thus, the solvent medium is an environmentally friendly and safe reaction medium, and can reduce the pollution of environment.

Embodiment 1

[0023] 70 ml of polyethylene glycol 200 (200 represents the molecular weight of polyethylene glycol) was added to 28 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.68 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0024] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 200 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 82.2%.

Embodiment 2

[0025] 63 ml of polyethylene glycol 200 (200 represents the molecular weight of polyethylene glycol) was added to 38 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.51 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0026] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 200 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 92.3%.

Embodiment 3

[0027] 55 ml of polyethylene glycol 300 (300 represents the molecular weight of polyethylene glycol) was added to 44 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.44 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0028] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 300 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 94.2%.

Embodiment 4

[0029] 50 ml of polyethylene glycol 200 (200 represents the molecular weight of polyethylene glycol) was added to 50 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.39 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0030] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 200 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 94.8%.

Embodiment 5

[0031] 44 ml of polyethylene glycol 200 (200 represents the molecular weight of polyethylene glycol, the same below) was added to 55 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.35 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0032] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 200 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 91.9%.

Embodiment 6

[0033] 50 ml of polyethylene glycol 400 (400 represents the molecular weight of polyethylene glycol, the same below) was added to 50 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.39 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0034] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 400 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 93.7%.

Embodiment 7

[0035] 40 ml of polyethylene glycol 600 was added to 60 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.32 mol L.sup.1. After stirring evenly, 5 ml 3.04% (0.0022 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2.5 h later, 5 ml 0.24% (0.0002 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0036] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 600 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 95.0%.

Embodiment 8

[0037] 50 ml of polyethylene glycol 300 (300 represents the molecular weight of polyethylene glycol) was added to 20 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 1.6 ml (0.02 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 0.93 mol L.sup.1. After stirring evenly, 5 ml 3.18% (0.0023 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2 h later, 5 ml 0.36% (0.0003 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0038] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 300 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 90.6%.

Embodiment 9

[0039] 50 ml of polyethylene glycol 500 (500 represents the molecular weight of polyethylene glycol) was added to 20 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 2.4 ml (0.03 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 1.34 mol L.sup.1. After stirring evenly, 5 ml 3.18% (0.0023 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2 h later, 5 ml 0.36% (0.0003 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0040] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 500 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 88.7%.

Embodiment 10

[0041] 50 ml of polyethylene glycol 200 (200 represents the molecular weight of polyethylene glycol) was added to 20 ml of deionized water, after mixing uniformly under stirring a solvent medium is obtained. Then 0.345 g (0.002 mol) 2-chloro-4-nitroaniline was dissolved in the solvent medium and 3.2 ml (0.04 mol) of concentrated hydrochloric acid was added, the resulting solution was transferred to a three-necked flask equipped with a magnetic stirrer and a thermometer, and then was cooled to 0-5 C. The H.sup.+ concentration of the solvent medium was 1.72 mol L.sup.1. After stirring evenly, 5 ml 3.18% (0.0023 mol) of sodium nitrite aqueous solution was slowly added to the reaction solution. 2 h later, 5 ml 0.36% (0.0003 mol) of urea aqueous solution was added to decompose the excessive nitrous acid, stirring was continued for 15 mins to prepare a diazonium salt solution.

[0042] 0.205 g (0.0022 mol) aniline dissolved in 5 ml of polyethylene glycol 200 was slowly and dropwise added to the above diazonium salt solution, and 30% NaOH aqueous solution was used to adjust the reaction solution so that the pH is equal to 6, and the reaction is performed at 0-5 C. for 3 h. Subsequently, the reaction solution was diluted with deionized water, filtered by suction and washed until neutral, then the collected product was dried under vacuum at 50 C. to get a crude product of a specialized dye precursor, and the yield is 85.8%.

[0043] The above preferred embodiments are described for illustration only, and are not intended to limit the scope of the invention. It should be understood, for a person skilled in the art, that various improvements or variations can be made herein without departing from the spirit and scope of the invention, and these improvements or variations should be covered within the protecting scope of the invention.