CN112778141B - Preparation method of 2-amino-5-nitrophenol - Google Patents
Preparation method of 2-amino-5-nitrophenol Download PDFInfo
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Abstract
The invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps: (1) Performing cyclization reaction on 2-aminophenol and thionyl chloride in a solvent and an acid-binding agent to obtain a cyclic compound; (2) Then the generated cyclic compound and mixed acid consisting of concentrated sulfuric acid and concentrated nitric acid are subjected to nitration reaction to obtain a nitrated substance; (3) And finally, hydrolyzing the generated nitride with sodium hydroxide to obtain the 2-amino-5-nitrophenol. The method provided by the invention can avoid using phosgene, or using expensive acetic anhydride, or using a urea method to generate a large amount of ammonia; the preparation method provided by the invention is simple to operate, the product has good appearance, good quality, high yield and easily controlled process conditions, and is easy for industrial automation and large-scale production.
Description
Technical Field
The invention relates to the technical field of chemical industry, in particular to a preparation method of a chemical intermediate 2-amino-5-nitrophenol.
Background
2-amino-5-nitrophenol (ANP) is an important intermediate for synthesizing dyes, medicines, pesticides and the like, has wide application, and dozens of dyes synthesized by the 2-amino-5-nitrophenol, such as acid dyes, disperse dyes, solvent dyes, leather dyes and the like, are dye intermediates with great development prospect. But at the same time, safety and pollution issues are of increasing concern.
According to literature reports, the main synthetic process routes which have been industrialized are: (1) o-hydroxyacetanilide method; (2) a p-nitroaniline method; (3) ortho-aminophenol process. The traditional processes for producing 2-amino-5-nitrophenol by the o-hydroxyacetanilide method and the p-nitroaniline method have laggard processes, long flow, low yield, large amount of three wastes and difficult treatment; the o-aminophenol method is a synthetic method with low cost, small danger, high yield and relatively few three wastes.
The 2-amino-5-nitrophenol is synthesized by an ortho-aminophenol method, and benzoxazolone is generated to protect amino by a phosgene method, a urea method and an acetic anhydride method, and then the 2-amino-5-nitrophenol is obtained by nitration and hydrolysis. However, the phosgene method has high toxicity, is not suitable for production in general factories, has higher cost of an acetic anhydride route, and the urea method has low price of urea, greatly reduces the total production cost, has the total yield of 50 percent, but generates a large amount of ammonia gas in the production process.
Disclosure of Invention
In order to solve the technical problems, the invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps:
(1) Dissolving 2-aminophenol in a solvent, adding an acid binding agent, then dropwise adding thionyl chloride, slowly heating to react, cooling to 20-30 ℃ after the reaction is finished, and performing suction filtration and drying to obtain a cyclic compound;
(2) Dissolving the cyclic compound prepared in the step (1) in a solvent, dropwise adding mixed acid consisting of concentrated sulfuric acid and concentrated nitric acid, slowly heating to carry out nitration reaction, cooling to 20-30 ℃ after the reaction is finished, carrying out suction filtration, and drying to obtain a nitrated compound;
(3) Dissolving the nitride prepared in the step (2) in a solvent, firstly dropwise adding a sodium hydroxide solution with the concentration of 10-15%, slowly heating to 80-100 ℃ for reaction for 6-8h, cooling to 20-30 ℃ after the reaction is finished, then adjusting the pH of the mixture to 6-7 by using hydrochloric acid, and carrying out suction filtration, washing and drying to obtain 2-amino-5-nitrophenol;
the chemical equation for the preparation of 2-amino-5-nitrophenol is as follows:
wherein the concentration of the concentrated sulfuric acid is 98%, the concentration of the concentrated nitric acid is 68%, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 1.
In the step (1), the mass ratio of the 2-aminophenol to the solvent is 1.
Preferably, the first and second electrodes are formed of a metal,
the mass ratio of the 2-aminophenol to the solvent is 1;
the molar ratio of the 2-aminophenol to the acid scavenger is 1.5,1;
the molar ratio of the 2-aminophenol to the thionyl chloride is 1.2,1.
In the step (2), the mass ratio of the cyclic compound to the solvent is 1.
Preferably, the first and second electrodes are formed of a metal,
the mass ratio of the cyclic compound to the solvent is 1;
the molar ratio of the cyclic compound to the concentrated nitric acid is 1.1, 1.
In the step (3), the mass ratio of the nitride to the solvent is 1.
Preferably, the first and second liquid crystal display panels are,
the mass ratio of the nitrated compound to the solvent is 1, 2, 1;
the molar ratio of the nitrated compound to the sodium hydroxide is 1.2,1.
Wherein, the solvent in the step (1) is any one or the combination of any several of water, ethyl acetate, trichloromethane, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether, toluene and chlorobenzene; the acid-binding agent is any one or combination of any more of triethylamine, diethylamine, ethylenediamine, ammonia water, sodium carbonate, sodium bicarbonate, potassium carbonate and pyridine.
Wherein, the solvent in the step (2) is any one or combination of any several of water, methanol, ethanol, ethyl acetate, trichloromethane, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether and toluene.
Wherein, the solvent in the step (3) is any one or combination of any several of water, methanol, ethanol, ethyl acetate, trichloromethane, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether and toluene.
Wherein in the step (1), the reaction temperature is 60-100 ℃ and the reaction time is 5-8h.
Preferably, the first and second electrodes are formed of a metal,
the reaction temperature is 65 ℃,70 ℃,75 ℃,80 ℃,85 ℃,90 ℃ and 95 ℃;
the reaction time was 5.5h,6h,6.5h,7h,7.5h.
Wherein in the step (2), the temperature of the nitration reaction is 40-80 ℃ and the time is 3-5h.
Preferably, the first and second liquid crystal display panels are,
the temperature of the nitration reaction is 45 ℃,50 ℃,55 ℃,60 ℃,65 ℃,70 ℃ and 75 ℃;
the time of the nitration reaction is 3.5h,4.0h and 4.5h.
The invention has the beneficial effects that:
the preparation method provided by the invention adopts a thionyl chloride method which takes o-aminophenol as a raw material to prepare the 2-amino-5-nitrophenol, and avoids using phosgene, or more expensive acetic anhydride, or a urea method to generate a large amount of ammonia. The preparation method provided by the invention is simple to operate, the product has good appearance, good quality, high yield and easily controlled process conditions, and is easy for industrial automation and large-scale production.
Detailed Description
The following is a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements are also considered to be within the scope of the present invention.
Example 1
The invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps:
(1) Synthesis of cyclic compound:
2-aminophenol (0.40mol, 43.7 g), sodium bicarbonate (0.48mol, 40.3g) and 200g of toluene are added into a 250mL three-neck flask, thionyl chloride (0.48mol, 56.6 g) is slowly added dropwise under the protection of nitrogen, the mixture is heated to 80 ℃ and kept warm for 8 hours, after the reaction is finished, the mixture is cooled to 25 ℃, and 58.6g of cyclic compound is obtained after suction filtration and vacuum drying, wherein the yield is 94.5%.
(2) And (3) synthesis of a nitrated compound:
adding a cyclic compound (0.35mol, 54.3g) and 200g dichloroethane into a 250mL three-neck flask, dropwise adding mixed acid (28 mL of 98% concentrated sulfuric acid and 28mL of 68% concentrated nitric acid with the mol number of 0.42 mol) under the protection of nitrogen, after 1h of dropwise adding, heating to 60 ℃, keeping the temperature for 5h, cooling to 25 ℃, filtering, washing a filter cake with water, and drying in vacuum at 80 ℃ to obtain 67.2g of earthy yellow nitride, wherein the yield is 96.0%.
(3) Synthesis of 2-amino-5-nitrophenol:
adding a nitrated compound (0.30mol, 60.0g) and 150g of methanol into a 250mL three-neck flask, slowly dropwise adding 15% sodium hydroxide (0.45mol, 120.0g) under the protection of nitrogen, heating to 90 ℃ after dropwise adding, refluxing for 6 hours, evaporating ethanol, recovering, adding activated carbon for decolorization, filtering, adjusting the pH value of filtrate to be 5 by using hydrochloric acid, separating out a product, filtering the product, and performing vacuum drying at 80 ℃ to obtain 43.0g of light yellow 2-amino-5-nitrophenol crystals, wherein the yield is 93.1%.
Example 2
The invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps:
(1) Synthesis of cyclic compound:
2-aminophenol (0.40mol, 43.7 g), triethylamine (0.48mol, 48.5 g) and 200g of toluene are added into a 250mL three-neck flask, thionyl chloride (0.48mol, 56.6 g) is slowly added dropwise under the protection of nitrogen, the temperature is kept for 6h after the reaction is heated to 80 ℃, the temperature is cooled to 20 ℃ after the reaction is finished, and 57.1g of cyclic compound is obtained after suction filtration and vacuum drying, wherein the yield is 92.1%.
(2) And (3) synthesis of a nitride:
adding a cyclic compound (0.35mol, 54.3g) and 200g of toluene into a 250mL three-neck flask, dropwise adding mixed acid (28 mL of 98% concentrated sulfuric acid and 28mL of 68% concentrated nitric acid with the mole number of 0.42 mol) under the protection of nitrogen, after 1h of dropwise adding, heating to 50 ℃, preserving the temperature for 6h, then cooling to 20 ℃, filtering, washing a filter cake with water, and drying in vacuum at 80 ℃ to obtain 64.1g of earthy yellow nitride, wherein the yield is 91.6%.
(3) Synthesis of 2-amino-5-nitrophenol:
adding a nitrated compound (0.30mol, 60.0 g) and 150g of methanol into a 250mL three-neck flask, slowly and dropwise adding 15% sodium hydroxide (0.36mol, 96.0 g) under the protection of nitrogen, heating to 85 ℃ after dropwise adding, refluxing for 7 hours, evaporating ethanol, recovering, adding activated carbon for decolorization, filtering, adjusting the pH of filtrate to 6 by hydrochloric acid, separating out a product, filtering the product, and performing vacuum drying at 80 ℃ to obtain 43.2g of light yellow 2-amino-5-nitrophenol crystals, wherein the yield is 93.5%.
Example 3
The invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps:
(1) Synthesis of cyclic compound:
2-aminophenol (0.40mol, 43.7 g), sodium carbonate (0.48mol, 50.8g) and 200g of toluene are added into a 250mL three-neck flask, thionyl chloride (0.48mol, 56.6 g) is slowly added dropwise under the protection of nitrogen, the mixture is heated to 80 ℃ and kept warm for 8 hours, after the reaction is finished, the mixture is cooled to 25 ℃, and 58.6g of cyclic compound is obtained after suction filtration and vacuum drying, wherein the yield is 94.5%.
(2) And (3) synthesis of a nitrated compound:
adding a cyclic compound (0.35mol, 54.3g) and 200g dichloroethane into a 250mL three-neck flask, dropwise adding mixed acid (28 mL of 98% concentrated sulfuric acid and 28mL of 68% concentrated nitric acid with the mol number of 0.42 mol) under the protection of nitrogen, after 1h of dropwise adding, heating to 70 ℃, keeping the temperature for 6h, then cooling to 30 ℃, filtering, washing a filter cake with water, and drying in vacuum at 80 ℃ to obtain 64.6g of earthy yellow nitride, wherein the yield is 92.3%.
(3) Synthesis of 2-amino-5-nitrophenol:
adding a nitrated compound (0.30mol, 60.0 g) and 150g of water into a 250mL three-neck flask, slowly dropwise adding 10% sodium hydroxide (0.36mol, 96.0 g) under the protection of nitrogen, heating to 850 ℃ after dropwise adding, refluxing for 8h, evaporating ethanol, recovering, adding activated carbon for decolorization, filtering, adjusting the pH of filtrate to 5.5 by hydrochloric acid, separating out a product, filtering the product, and drying in vacuum at 80 ℃ to obtain 42.1g of light yellow 2-amino-5-nitrophenol crystals, wherein the yield is 91.0%.
Example 4
The invention provides a preparation method of 2-amino-5-nitrophenol, which comprises the following steps:
(1) Synthesis of cyclic compound:
2-aminophenol (0.40mol, 43.7 g), pyridine (0.48mol, 40.3g) and 200g of toluene are added into a 250mL three-neck flask, thionyl chloride (0.48mol, 56.6 g) is slowly added dropwise under the protection of nitrogen, the mixture is heated to 75 ℃ and kept warm for 6 hours, after the reaction is finished, the mixture is cooled to 28 ℃, and 58.3g of cyclic compound is obtained after suction filtration and vacuum drying, wherein the yield is 93.0%.
(2) And (3) synthesis of a nitrated compound:
adding a cyclic compound (0.35mol, 54.3g) and 200g dichloroethane into a 250mL three-neck flask, dropwise adding mixed acid (28 mL of 98% concentrated sulfuric acid and 28mL of 68% concentrated nitric acid with the mol number of 0.42 mol) under the protection of nitrogen, after 1h of dropwise adding, heating to 90 ℃, preserving the temperature for 5h, then cooling to 20 ℃, filtering, washing a filter cake with water, and drying in vacuum at 80 ℃ to obtain 66.1g of earthy yellow nitride, wherein the yield is 94.5%.
(3) Synthesis of 2-amino-5-nitrophenol:
adding a nitrated compound (0.30mol, 60.0 g) and 150g of ethanol into a 250mL three-neck flask, slowly and dropwise adding 10% sodium hydroxide (0.36mol, 96.0 g) under the protection of nitrogen, heating to 85 ℃ after dropwise adding, refluxing for 7 hours, evaporating the ethanol, recovering, adding activated carbon for decolorization, filtering, adjusting the pH of filtrate to 5-6 by using hydrochloric acid, separating out a product, filtering the product, and performing vacuum drying at 80 ℃ to obtain 42.3g of a light yellow 2-amino-5-nitrophenol crystal, wherein the yield is 91.5%.
To verify the effect of the molar ratio of 2-aminophenol to thionyl chloride on the yield of cyclic compounds, a first set of comparative experiments was set up by adjusting the molar ratio of 2-aminophenol to thionyl chloride as shown in table 1 below with reference to example 1, with other process parameters being controlled constant.
TABLE 12 influence of the molar ratio of aminophenol to thionyl chloride on the yield of cyclic compounds
As can be seen from Table 1, when the molar ratio of 2-aminophenol to thionyl chloride is 1; the yield and yield of the cyclic compound are optimum when the molar ratio of 2-aminophenol to thionyl chloride is in the range of 1.
To verify the effect of the molar ratio of cyclic compound to concentrated nitric acid on the yield of nitrated compound, a second set of comparative experiments was set up by adjusting the molar ratio of cyclic compound to concentrated nitric acid, as shown in table 2, with reference to example 1, and with other process parameters being kept constant.
TABLE 2 influence of the molar ratio of cyclics to concentrated nitric acid on the yield of nitrated compounds
As can be seen from Table 2, when the molar ratio of the cyclic compound to the concentrated nitric acid is in the range of 1 to 1.4, the yield and yield of the nitrated compound are high, and above this range the yield and yield decrease is significant, and a dinitro compound is produced, so the molar ratio of the cyclic compound to the concentrated nitric acid is preferably in the range of 1.
To verify the effect of the molar ratio of the nitrated compound to sodium hydroxide on the yield of 2-amino-5-nitrophenol, a third set of comparative experiments was set up by adjusting the molar ratio of the nitrated compound to sodium hydroxide, as shown in table 3, below with reference to example 1, with other process parameters being controlled.
TABLE 3 influence of the molar ratio of nitrated compound to sodium hydroxide on the yield of 2-amino-5-nitrophenol
As can be seen from Table 3, the yield and yield of 2-amino-5-nitrophenol are highest when the molar ratio of the nitrated compound to sodium hydroxide is 1-2; when the molar ratio of the nitrated compound to sodium hydroxide is higher than 1-2, the yield and yield of 2-amino-5-nitrophenol are significantly reduced, so the molar ratio of the nitrated compound to sodium hydroxide is preferably 1.
To verify the effect of the temperature of the nitration reaction on the yield of the nitrated compound, a fourth set of comparative experiments was set up by adjusting the temperature of the nitration reaction, as shown in table 4, with reference to example 1 below, while keeping the other process parameters constant.
TABLE 4 influence of the temperature of the nitration reaction on the yield of the nitrated compound
| Comparative test | Temperature (. Degree.C.) of nitration reaction | Yield of nitrated compound (g) | Yield of nitroxide (%) |
| Comparative experiment 1 | 30 | 62.7 | 89.6 |
| Comparative experiment 2 | 35 | 64.6 | 92.3 |
| Comparative experiment 3 | 40 | 66.5 | 95.0 |
| Comparative experiment 4 | 50 | 66.9 | 95.6 |
| Comparative experiment 5 | 60 | 67.2 | 96.0 |
| Comparative test 6 | 70 | 67.0 | 95.7 |
| Comparative experiment 7 | 80 | 66.8 | 95.4 |
| Comparative experiment 8 | 85 | 65.0 | 92.9 |
| Comparative test 9 | 90 | 63.8 | 90.0 |
As can be seen from Table 4, when the temperature of the nitration reaction is 40-80 ℃, the yield and yield of the nitrated compound are high; when the temperature of the nitration reaction is below 40 ℃ or above 80 ℃, the yield and yield of the nitrated product are reduced, and therefore the temperature of the nitration reaction is preferably 40-80 ℃.
The above examples only express the specific embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the spirit of the present invention, and these changes and modifications are all within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.
Claims (10)
1. A preparation method of 2-amino-5-nitrophenol is characterized by comprising the following steps:
(1) Dissolving 2-aminophenol in a solvent, adding an acid binding agent, then dropwise adding thionyl chloride, slowly heating to react, cooling to 20-30 ℃ after the reaction is finished, and performing suction filtration and drying to obtain a cyclic compound;
(2) Dissolving the cyclic compound prepared in the step (1) in a solvent, dropwise adding mixed acid consisting of concentrated sulfuric acid and concentrated nitric acid, slowly heating to carry out nitration reaction, cooling to 20-30 ℃ after the reaction is finished, carrying out suction filtration, and drying to obtain a nitrated compound;
(3) Dissolving the nitride prepared in the step (2) in a solvent, firstly dropwise adding a sodium hydroxide solution with the concentration of 10-15%, slowly heating to 80-100 ℃ for reaction for 6-8h, cooling to 20-30 ℃ after the reaction is finished, then adjusting the pH of the mixture to 6-7 by using hydrochloric acid, and carrying out suction filtration, washing and drying to obtain 2-amino-5-nitrophenol;
the chemical equation for the preparation of 2-amino-5-nitrophenol is as follows:
2. the process for producing 2-amino-5-nitrophenol according to claim 1, wherein: the concentration of the concentrated sulfuric acid is 98%, the concentration of the concentrated nitric acid is 68%, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 1.
3. The method for producing 2-amino-5-nitrophenol according to claim 1, characterized in that: in the step (1), the mass ratio of the 2-aminophenol to the solvent is 1.
4. The method for producing 2-amino-5-nitrophenol according to claim 1, characterized in that: in the step (2), the mass ratio of the cyclic compound to the solvent is 1.
5. The process for producing 2-amino-5-nitrophenol according to claim 1, wherein: in the step (3), the mass ratio of the nitrated compound to the solvent is 1-2, and the molar ratio of the nitrated compound to the sodium hydroxide is 1.
6. The process for producing 2-amino-5-nitrophenol according to any of claims 1 to 5, characterized in that: the solvent in the step (1) is any one or combination of any more of water, ethyl acetate, trichloromethane, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether, toluene and chlorobenzene; the acid-binding agent is any one or combination of any more of triethylamine, diethylamine, ethylenediamine, ammonia water, sodium carbonate, sodium bicarbonate, potassium carbonate and pyridine.
7. The process for producing 2-amino-5-nitrophenol according to any of claims 1 to 5, characterized in that: in the step (2), the solvent is any one or combination of any several of water, methanol, ethanol, ethyl acetate, trichloromethane, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether and toluene.
8. The process for producing 2-amino-5-nitrophenol according to any one of claims 1 to 5, wherein: in the step (3), the solvent is any one or combination of any several of water, methanol, ethanol, ethyl acetate, chloroform, dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, tert-butyl methyl ether and toluene.
9. The process for producing 2-amino-5-nitrophenol according to any one of claims 1 to 5, wherein: in the step (1), the reaction temperature is 60-100 ℃ and the reaction time is 5-8h.
10. The process for producing 2-amino-5-nitrophenol according to any one of claims 1 to 5, wherein: in the step (2), the temperature of the nitration reaction is 40-80 ℃ and the time is 3-5h.
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| WO1992005164A1 (en) * | 1990-09-19 | 1992-04-02 | Pfizer Inc. | Novel aminobenzosultam derivatives as lipoxygenase inhibitors |
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|---|---|---|---|---|
| WO1992005164A1 (en) * | 1990-09-19 | 1992-04-02 | Pfizer Inc. | Novel aminobenzosultam derivatives as lipoxygenase inhibitors |
| CN105669477A (en) * | 2016-03-14 | 2016-06-15 | 九江善水科技有限公司 | Method for producing 5-nitro-2aminophenol |
| CN110156712A (en) * | 2019-04-25 | 2019-08-23 | 邵玉田 | It is a kind of to utilize aromatic nitration by-product synthesis benzoxazoles class compound and application |
| CN111018736A (en) * | 2019-12-12 | 2020-04-17 | 苏州诚和医药化学有限公司 | Novel method for preparing 3-hydroxy-4-amino-5-nitro-N, N-dimethyl benzamide |
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