A process for the preparation of 1,4-naphthoquinone by oxidation of naphthalene

Abstract

The application discloses a method for preparing 1,4-naphthoquinone by oxidizing naphthalene. The method comprises the following steps: mixing raw materials containing naphthalene and hydrogen peroxide with a solvent and a catalyst, and reacting to obtain a product containing 1,4-naphthoquinone. The synthesis method is simple, no heavy metal wastewater is discharged, is green, safe, environment-friendly, high in naphthalene conversion rate and 1,4-naphthoquinone selectivity, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing 1,4-naphthalenequinone by naphthalene oxidation, belonging to the field of chemical engineering. BACKGROUND

[0002] Naphthalene is the most important fused ring aromatic hydrocarbon in industry, and the oxygen-containing organic chemicals synthesized by oxidation reaction occupy an important position in petrochemical products. Naphthalene can be converted into 1,4-naphthalenequinone by oxidation reaction. 1,4-Naphthalenequinone is an important raw material in fine chemical industry, and is an intermediate of medicine, dye, perfume, pesticide, plasticizer, etc. It is not only a polymerization regulator for synthetic rubber and resin, but also an important raw material for synthesizing new paper cooking aids. 1,4-Naphthalenequinone has excellent ultraviolet absorption performance and visible near-infrared reflection function, which makes it have important significance in the functional finishing of textiles. At the same time, naphthalenequinone has good antiseptic and bactericidal properties, and is a good antiseptic and bactericide. The product is in short supply on the market, and its demand has a trend of increasing substantially. In China, due to the small number of production plants and small device scale, the market is in short supply. Therefore, it is of great significance to develop a synthesis method of naphthalenequinone suitable for industrial production.

[0003] At present, 1,4-naphthalenequinone is mainly prepared by gas phase oxidation and liquid phase oxidation of naphthalene in industry. The gas phase oxidation method mainly uses oxygen in air to directly oxidize naphthalene into naphthalenequinone under the action of a catalyst. This method has poor reaction selectivity, low yield, and mainly produces phthalic anhydride as a byproduct. For a long time, the liquid phase oxidation method of naphthalene needs to involve stoichiometric amounts of heavy metal-based catalysts such as chromium, so a large amount of industrial wastewater containing heavy metals is generated in industrial production, and the treatment process of these wastewater is difficult and complicated, which will cause serious pollution to the environment. Since the 1970s, researchers have tried to develop new catalysts to solve the problem of chromium-containing wastewater. Although some visible results have been achieved in pollution control, the conversion rate of naphthalene and the selectivity of 1,4-naphthalenequinone are still low. Therefore, the research on the liquid phase catalytic oxidation of naphthalene is still focused on developing suitable catalysts to improve the conversion rate of naphthalene and the selectivity of 1,4-naphthalenequinone. SUMMARY

[0004] The purpose of the present application is to solve the problem of low conversion rate of naphthalene and low selectivity of 1,4-naphthalenequinone. In order to solve the above problem, the present application provides a method for preparing 1,4-naphthalenequinone by naphthalene oxidation.

[0005] The present application uses naphthalene as raw material, hydrogen peroxide as oxygen source, and occurs oxidation reaction in the presence of organic acid solvent and catalyst acetylacetone metal salt to prepare 1,4-naphthalenequinone.

[0006] According to one aspect of the present application, a method for preparing 1,4-naphthalenequinone by naphthalene oxidation is provided, which at least comprises the following steps:

[0007] A raw material containing naphthalene and hydrogen peroxide is mixed with a solvent and a catalyst and reacted to obtain a product containing 1,4-naphthoquinone.

[0008] The concentration of the hydrogen peroxide is 30-70%;

[0009] The molar ratio of hydrogen peroxide to naphthalene is 1.0 to 10.0:1, calculated based on the amount of hydrogen peroxide.

[0010] The solvent is selected from at least one of formic acid, acetic acid, propionic acid or butyric acid;

[0011] The mass ratio of the solvent to naphthalene is 1.0-19.0:1.

[0012] The catalyst is selected from acetylacetonate metal salt or inorganic acid catalyst;

[0013] The acetylacetonate metal salt is selected from at least one of ferric acetylacetonate, cobalt acetylacetonate, vanadium acetylacetonate, nickel acetylacetonate, titanium acetylacetonate or copper acetylacetonate;

[0014] The inorganic acid catalyst is selected from at least one of sulfuric acid, hydrochloric acid, nitric acid or phosphoric acid;

[0015] The mass of the catalyst accounts for 0.5 to 5 wt% of the mass of the solvent.

[0016] The reaction temperature is 40-90°C;

[0017] The reaction time is 2 to 8 hours.

[0018] The hydrogen peroxide is added dropwise;

[0019] After the addition is complete, stir for 2 to 8 hours.

[0020] The specific steps are as follows:

[0021] In the presence of an organic acid solvent and a catalyst, acetylacetonate metal salt, hydrogen peroxide and naphthalene undergo oxidation reaction to prepare 1,4-naphthoquinone.

[0022] Compared with the prior art, the method for preparing 1,4-naphthoquinone by oxidizing naphthalene provided by the present invention has the following technical features and beneficial effects:

[0023] 1. The present invention uses naphthalene as a raw material and hydrogen peroxide as an oxygen source to produce 1,4-naphthoquinone by an oxidation reaction in the presence of an organic acid solvent and a catalyst, a metal salt of acetylacetonate. This method utilizes the strong oxidizing properties of hydrogen peroxide in an acidic solvent to selectively oxidize naphthalene to 1,4-naphthoquinone under the catalytic action of transition metals such as iron, cobalt, vanadium, nickel, titanium, and copper.

[0024] 2. The present invention utilizes hydrogen peroxide to oxidize naphthalene to prepare 1,4-naphthoquinone. The preparation method is simple, the reaction conditions are easy to achieve, the catalyst is a transition metal salt, and the discharge of heavy metal wastewater is avoided. The obtained product 1,4-naphthoquinone has a high yield and is suitable for industrial production. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the following embodiments. However, the present invention is not limited to the following embodiments. Any similar structure and similar variations of the present invention are included in the protection scope of the present invention.

[0026] Example 1

[0027] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 40g of acetic acid, and 0.2g of ferric acetylacetonate were added. The mixture was heated and maintained at 40°C. 10.6g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 8 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 55.6% and a 1,4-naphthoquinone selectivity of 92.1%. The conversion of hydrogen peroxide was calculated to be 95.4% by redox titration.

[0028] Example 2

[0029] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 15g of naphthalene, 285g of propionic acid, and 1.43g of ferric acetylacetonate were added. The mixture was heated and maintained at 60°C. 15.9g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 67.2% and a 1,4-naphthoquinone selectivity of 92.5%. The conversion of hydrogen peroxide was calculated to be 98.4% using redox titration.

[0030] Example 3

[0031] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of butyric acid, and 1.13g of vanadyl acetylacetonate were added. The mixture was heated and maintained at 60°C. 10.6g of 50% hydrogen peroxide was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 58.6% and a 1,4-naphthoquinone selectivity of 90.1%. The conversion of hydrogen peroxide was calculated to be 96.5% by redox titration.

[0032] Example 4

[0033] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of formic acid, and 1.13g of cobalt acetylacetonate were added. The mixture was heated and maintained at 60°C. 10.6g of 50% hydrogen peroxide was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 50.3% and a 1,4-naphthoquinone selectivity of 93.4%. The conversion of hydrogen peroxide was calculated by redox titration to be 97.4%.

[0034] Example 5

[0035] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of acetic acid, and 1.13g of titanium acetylacetonate were added. The mixture was heated and maintained at 60°C. 53.0g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 65.6% and a 1,4-naphthoquinone selectivity of 93.2%. The conversion of hydrogen peroxide was calculated by redox titration to be 98.3%.

[0036] Example 6

[0037] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of acetic acid, and 1.13g of copper acetylacetonate were added. The mixture was heated and maintained at 90°C. 53.0g of hydrogen peroxide (30%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 2 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 53.1% and a 1,4-naphthoquinone selectivity of 95.1%. The conversion of hydrogen peroxide was calculated to be 96.8% by redox titration.

[0038] Example 7

[0039] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of acetic acid, and 5.66g of nickel acetylacetonate were added. The mixture was heated and maintained at 90°C. 25.0g of hydrogen peroxide (70%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 2 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 70.6% and a selectivity for 1,4-naphthoquinone of 89.1%. The conversion of hydrogen peroxide, calculated by redox titration, was 98.4%.

[0040] Example 8

[0041] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 40g of acetic acid, and 0.2g of concentrated sulfuric acid were added. The mixture was heated and maintained at 40°C. 10.6g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 8.0 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 65.6% and a selectivity for 1,4-naphthoquinone of 82.3%. The conversion of hydrogen peroxide was calculated to be 97.4% using redox titration.

[0042] Example 9

[0043] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 15g of naphthalene, 285g of propionic acid, and 1.43g of hydrochloric acid were added. The mixture was heated and maintained at 60°C. 15.9g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 57.2% and a selectivity for 1,4-naphthoquinone of 82.5%. The conversion of hydrogen peroxide, calculated by redox titration, was 94.4%.

[0044] Example 10

[0045] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of butyric acid, and 1.13g of phosphoric acid were added. The mixture was heated and maintained at 60°C. 10.6g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 48.6% and a selectivity for 1,4-naphthoquinone of 80.1%. The conversion of hydrogen peroxide was calculated to be 86.5% by redox titration.

[0046] Example 1

[0047] To a 500mL three-necked flask equipped with a stirrer, thermometer, and reflux line, 20g of naphthalene, 113.3g of butyric acid, and 1.13g of nitric acid were added. The mixture was heated and maintained at 60°C. 10.6g of hydrogen peroxide (50%) was then added dropwise to the reaction mixture. After the addition was complete, the reaction was stirred and allowed to react for 6 hours. After the reaction, liquid chromatography analysis of the liquid product revealed a naphthalene conversion of 50.4% and a 1,4-naphthoquinone selectivity of 90.1%. The conversion of hydrogen peroxide was calculated to be 96.8% by redox titration.

[0048] The above merely describes several embodiments of the present application, and does not limit the present application in any form. Although the present application is disclosed with the preferred embodiments, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the disclosed technical contents without departing from the scope of the technical solutions of the present application, and the equivalent embodiments are equivalent to the equivalent embodiments, which are within the scope of the technical solutions.

Claims

1. A method for preparing 1,4-naphthoquinone by oxidation of naphthalene, characterized in that: At least the following steps are included: A raw material containing naphthalene and hydrogen peroxide is mixed with a solvent and a catalyst, and reacted to obtain a product containing 1,4-naphthoquinone; The solvent is selected from at least one of formic acid, acetic acid, propionic acid or butyric acid; The catalyst is selected from acetylacetonate metal salt; The mass of the catalyst accounts for 0.5 to 5 wt% of the mass of the solvent.

2. The method according to claim 1, characterized in that The concentration of the hydrogen peroxide is 30-70%; The molar ratio of hydrogen peroxide to naphthalene is 1.0 to 10.0:1, calculated based on the amount of hydrogen peroxide.

3. The method according to claim 1, characterized in that The mass ratio of the solvent to naphthalene is 1.0-19.0:

1.

4. The method according to claim 1, wherein The acetylacetonate metal salt is selected from at least one of iron acetylacetonate, cobalt acetylacetonate, vanadium acetylacetonate, nickel acetylacetonate, titanium acetylacetonate or copper acetylacetonate.

5. The method according to claim 1, wherein The reaction temperature is 40-90°C; The reaction time is 2 to 8 hours.

6. The method according to claim 1, characterized in that The hydrogen peroxide is added dropwise; After the addition is complete, stir for 2 to 8 hours.