阅读说明：本技术 一种邻苯二胺的制备方法 (Preparation method of o-phenylenediamine ) 是由 罗先金 于 2021-01-28 设计创作，主要内容包括：本发明涉及一种邻苯二胺的制备方法,将邻苯二甲酸在酸催化下与醇酯化制备邻苯二甲酸酯,然后在醇类溶剂中通入氨气,得到邻苯二甲酰胺,然后在碱性溶液中与次卤酸盐或卤素反应来制备邻苯二胺。与现有技术相比,本发明完全避开了混酸硝化工艺,不会产生废酸,也不会出现邻氯硝基苯氨解时易发生安全事故,安全清洁高效。(The invention relates to a preparation method of o-phenylenediamine, which comprises the steps of esterifying phthalic acid and alcohol under the catalysis of acid to prepare phthalic acid ester, introducing ammonia gas into an alcohol solvent to obtain phthalic diamide, and reacting with hypohalite or halogen in an alkaline solution to prepare the o-phenylenediamine. Compared with the prior art, the method completely avoids a mixed acid nitration process, does not generate waste acid, is safe, clean and efficient, and is easy to cause safety accidents in the ammonolysis of o-chloronitrobenzene.)

1. The preparation method of o-phenylenediamine is characterized by comprising the following steps:

(1) phthalic acid is used as a starting material, and reacts with alcohol to prepare phthalic acid ester, and then aminolysis is carried out to prepare phthalic diamide;

(2) phthalic acid amide reacts with hypohalite or halogen in alkaline solution to prepare the o-phenylenediamine.

2. The method for producing o-phenylenediamine according to claim 1, wherein the step (1) comprises the steps of:

(1-1) carrying out esterification on phthalic acid and alcohol under acid catalysis to prepare phthalic acid ester;

(1-2) dissolving phthalic acid ester in an alcohol reagent, and introducing ammonia gas to prepare phthalic acid diamide.

3. The process for producing o-phenylenediamine according to claim 2, wherein in the step (1-1), phthalic acid is added to an alcohol, an acid catalyst is added, the esterification reaction is carried out by heating under reflux, water produced is removed by distillation, water is not regenerated when the temperature is higher than the boiling point of the alcohol, the esterification is completed, the remaining alcohol is continuously distilled off, a solvent is added, the mixture is washed with water to form layers, and after washing, the phthalate is obtained by distillation.

4. The process for producing an o-phenylenediamine according to claim 3, wherein the step (1-1) comprises at least one of the following conditions:

(i) the alcohol comprises C1-C18 fatty alcohol, preferably methanol, ethanol, propanol or isopropanol;

(ii) the acidic catalyst comprises inorganic acid concentrated sulfuric acid, organic acid p-toluenesulfonic acid or solid acid sulfonic acid resin.

5. The method for preparing o-phenylenediamine according to claim 2, wherein in the step (1-2), phthalic acid ester is dissolved in an alcohol reagent, ammonia gas is slowly introduced, the temperature is raised for reaction, then the temperature is reduced to room temperature, and the phthalic acid amide is obtained by filtering and washing.

6. A process for producing o-phenylenediamine according to claim 5, wherein the step (1-2) comprises at least one of the following conditions:

(i) the alcohol reagent comprises methanol, ethanol, propanol, isopropanol or ethylene glycol;

(ii) the molar ratio of the phthalic acid ester to the ammonia gas is 1: 2-50.

7. The method for preparing o-phenylenediamine according to claim 5, wherein in the step (1-2), ammonia gas is introduced, and then the temperature is raised to 30 to 120 ℃ to react until all the phthalic acid ester is converted into phthalic acid amide.

8. The method for preparing o-phenylenediamine according to claim 1, wherein in the step (2), the phthalic acid amide is added to the alkaline solution at a temperature of-5 to 35 ℃, hypohalite or halogen is added dropwise at the temperature, then the temperature is raised to 35 to 100 ℃, and then the temperature is lowered and filtered to obtain the o-phenylenediamine.

9. The method for preparing o-phenylenediamine according to claim 8, wherein in step (2), the phthalic acid amide is added into the alkaline solution at a temperature of 2-15 ℃, hypohalite or halogen is added dropwise at the temperature, the temperature is raised to 35 ℃, the temperature is raised to 75 ℃ after 30 minutes of heat preservation, the temperature is lowered, and the o-phenylenediamine is obtained by filtering.

10. The method according to claim 1, 8 or 9, wherein the alkaline solution comprises NaOH solution, KOH solution or Ca (OH)₂A solution; the hypohalite comprises sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, sodium hypobromite, potassium hypobromite or calcium hypobromite; the halogen includes chlorine or bromine.

Technical Field

The invention relates to a preparation method of o-phenylenediamine, in particular to a method for industrially producing o-phenylenediamine.

Background

The o-phenylenediamine is mainly used for manufacturing pesticide bactericides, reducing dyes, cationic dyes, polymer stabilizers, heterocyclic compounds, photosensitive materials, surfactants, antifreezing agents, copper anticorrosive agents and the like, and has wide application.

At present, the o-chloronitrobenzene is prepared by nitration of chlorobenzene mainly industrially, then the o-chloronitrobenzene is prepared by reaction with ammonia gas, and o-phenylenediamine is prepared by reduction, and the process route mainly has the following defects: two products, namely o-chloronitrobenzene and p-chloronitrobenzene, are produced in the first step of nitration, and high-purity products can be obtained only by separation and refining, and because mixed acid is required for nitration, a large amount of waste acid is generated; the second step of the reaction (ammonolysis) with ammonia gas must be finished under high temperature and high pressure, and because the ammonolysis reaction releases a large amount of heat, the temperature is difficult to control, the explosion danger is easy to occur, and a plurality of explosion accidents occur in China, which leads to casualties and heavy economic loss.

Disclosure of Invention

The present invention aims at providing one kind of o-phenylenediamine preparation process to overcome the demerits of available technology. Completely avoids the mixed acid nitration process, does not generate waste acid, does not easily generate safety accidents when the o-chloronitrobenzene is ammonolyzed, and is safe, clean and efficient.

The preparation method of the invention provides the following process route for preparing o-phenylenediamine: phthalic acid and alcohol are esterified under the catalysis of acid to prepare phthalic acid ester, ammonia gas is introduced into an alcohol solvent to obtain phthalic diamide, and then the phthalic acid amide and hypohalite or halogen react in an alkaline solvent to prepare o-phenylenediamine.

The specific reaction process is as follows:

wherein ROH is C1-C18 fatty alcohol.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of o-phenylenediamine comprises the following steps:

(1) phthalic acid is used as a starting material, and reacts with alcohol to prepare phthalic acid ester, and then aminolysis is carried out to prepare phthalic diamide;

(2) phthalic acid amide reacts with hypohalite or halogen in alkaline solution to prepare the o-phenylenediamine.

Preferably, step (1) comprises the following steps:

(1-1) carrying out esterification on phthalic acid and alcohol under acid catalysis to prepare phthalic acid ester;

(1-2) dissolving phthalic acid ester in an alcohol reagent, and introducing ammonia gas to prepare phthalic acid diamide.

Preferably, in the step (1-1), phthalic acid is added into alcohol, an acid catalyst is added, the temperature is raised and the reflux is carried out to carry out esterification reaction, water generated is removed by distillation (if the amount of alcohol is not enough to supplement the alcohol continuously in the reaction process), water is not regenerated when the temperature is higher than the boiling point of the alcohol, the esterification is finished, the residual alcohol is continuously distilled, a solvent is added, the mixture is washed by water to be layered, and after washing, the phthalate is obtained by distillation.

Preferably, in the step (1-1), the alcohol comprises a C1-C18 aliphatic alcohol, preferably methanol, ethanol, propanol or isopropanol.

Preferably, the acidic catalyst in step (1-1) comprises concentrated sulfuric acid of inorganic acid, p-toluenesulfonic acid of organic acid or sulfonic acid resin of solid acid.

Preferably, in the step (1-2), the phthalic acid ester is dissolved in an alcohol reagent, ammonia gas is slowly introduced, the temperature is raised for reaction, then the temperature is reduced to room temperature, and the phthalic acid ester is filtered and washed to obtain the phthalic acid amide.

Preferably, in the step (1-2), the alcohol reagent comprises methanol, ethanol, propanol, isopropanol or ethylene glycol.

Preferably, in the step (1-2), the molar ratio of the phthalate to the ammonia gas is 1: 2-50.

Preferably, in the step (1-2), ammonia gas is introduced, the temperature is raised to 30-120 ℃, and the reaction is carried out until all the phthalic acid ester becomes phthalic acid diamide.

Preferably, in the step (2), the phthalic acid amide is added into the alkaline solution at the temperature of-5-35 ℃, hypohalite or halogen is added dropwise at the temperature, then the temperature is raised to 35-100 ℃, and then the temperature is reduced and the phthalic acid amide is filtered to obtain the o-phenylenediamine.

Preferably, in the step (2), the phthalic acid amide is added into the alkaline solution at the temperature of 2-15 ℃, hypohalite or halogen is added at the temperature, then the temperature is raised to 35 ℃, the temperature is kept for 30 minutes, then the temperature is raised to 75 ℃, and then the temperature is lowered and the phthalic acid amide is filtered to obtain the o-phenylenediamine.

Preferably, the alkaline solution comprises NaOH solution, KOH solution or Ca (OH)₂A solution; the hypohalite comprises sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, sodium hypobromite, potassium hypobromite or calcium hypobromite; the halogen includes chlorine or bromine.

The invention takes phthalic acid as raw material, the esterification reaction is close to 100 percent under the catalysis of acid, then the yield of the phthalic acid amide prepared by ammonolysis reaches more than 95 percent, then the reaction yield of the phthalic acid amide and hypohalite or halogen in alkaline solution reaches 95 percent, and the target product can be prepared with high yield. The process route successfully avoids the phenomenon of temperature runaway easily occurring in the aminolysis of o-chloronitrobenzene in the prior art, successfully avoids the prior dangerous process and also avoids waste acid generated in the prior art. The three wastes in the whole production process can be discharged at low level, even zero discharge.

Compared with the prior art, the method for preparing o-phenylenediamine completely avoids a mixed acid nitration process, does not generate waste acid, is easy to cause safety accidents in the ammonolysis of o-chloronitrobenzene, and is safe, clean and efficient.

Detailed Description

The present invention will be described in detail with reference to specific examples.

Example 1:

adding 33.2g of phthalic acid into 300ml of methanol, adding 1ml of concentrated sulfuric acid, heating and refluxing for 12 hours, continuously collecting fractions at the temperature of below 66 ℃ to remove produced water, when the reflux temperature reaches above 67 ℃, evaporating to remove the residual methanol, adding 50ml of ethyl acetate and 20ml of water, washing in a layering manner, and distilling a solvent to obtain 38.7g of dimethyl phthalate. The yield thereof was found to be 99.7%.

Example 2:

adding 33.2g of phthalic acid into 300ml of methanol, adding 0.5g of p-toluenesulfonic acid, heating and refluxing for 13 hours, continuously collecting fractions at a temperature below 66 ℃ to remove produced water, when the reflux temperature reaches above 67 ℃, ending esterification, distilling to remove residual methanol, adding 50ml of ethyl acetate and 20ml of 0.5% liquid alkali, washing in layers, and distilling to obtain 38.6g of dimethyl phthalate. The yield thereof was found to be 99.5%.

Example 3:

adding 33.2g phthalic acid into 300ml ethanol, adding 3g solid acid sulfonic acid resin, heating and refluxing for 16 hours, continuously collecting fractions at 78 ℃ to remove produced water, finishing esterification when the reflux temperature reaches over 79 ℃, filtering, and distilling to obtain 44.2g diethyl phthalate. The yield thereof was found to be 99.5%.

Example 4:

38.8g of dimethyl phthalate is dissolved in 300ml of ethylene glycol, ammonia gas is slowly introduced, the temperature is raised to 70 ℃, after reaction for 7 hours, the temperature is reduced to about 20 ℃, and then filtration and washing are carried out, thus obtaining 29.8g of phthalic diamide. The yield thereof was found to be 91%.

Example 5:

38.8g of dimethyl phthalate is dissolved in 300ml of isopropanol, ammonia gas is slowly introduced, the temperature is raised to 82 ℃, after 7 hours of reaction, the temperature is lowered to about 20 ℃, and after filtration and washing, 31.2g of phthalic diamide is obtained. The yield thereof was found to be 95%.

Example 6:

82g of phthalic diamide is added into 10mol/L NaOH 200ml and 735g of 10% sodium hypochlorite solution at 10 ℃, after the addition, the temperature is raised to 35 ℃, then the temperature is preserved for 30 minutes, the temperature is raised to 75 ℃, the temperature is reduced, and the phthalic diamide (the target product) of 50.9g is obtained after filtration, washing and drying. The yield thereof was found to be 94.2%.

Example 7:

82g of phthalic diamide is added into 280ml of 15mol/L NaOH, the mixture is cooled to 5 ℃, 70g of chlorine gas is introduced at the temperature, the temperature is raised to 35 ℃ after the introduction, the temperature is kept for 30 minutes, the temperature is raised to 75 ℃, the temperature is lowered, the filtering is carried out, and the washing and the drying are carried out to obtain 51.7g of o-phenylenediamine (target product). The yield thereof was found to be 95.8%.

Example 8:

82g of phthalic diamide is added into 280ml of 15mol/L NaOH, the mixture is cooled to 5 ℃, 158g of bromine is added at the temperature, the temperature is raised to 35 ℃ after the addition, the temperature is kept for 30 minutes, the temperature is raised to 75 ℃, the temperature is lowered, and the filtering is carried out, so that 51.8g of o-phenylenediamine (target product) is obtained. The yield thereof was found to be 96.0%.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.