CN102850190A - Method for preparing mixed naphthol - Google Patents

Abstract

The invention discloses a method for preparing mixed naphthols from monoisopropylnaphthalene, which comprises purification and isomerization of monoisopropylnaphthalene, oxidation of monoisopropylnaphthalene under alkaline conditions, hydrolysis of oxidized products, Distillation and separation of mixed naphthols and other processes. The present invention has the advantages that it can reduce the complexity of preparing naphthol by the oxidation of isopropylnaphthalene, reduce the operating cost and loss of the process, and improve the yield and quality of naphthol. It is an efficient, clean, atom-economical high-efficiency The preparation process of naphthol.

Description

A kind of method for preparing mixed naphthols

technical field

The present invention relates to the preparation technology of compound, specifically, relate to be raw material by monoisopropyl naphthalene (IPN), through purification, isomerization, alkali washing, oxidation reaction, acid hydrolysis reaction, primary separation and naphthol rectification , to produce mixed naphthols.

Background technique

Naphthol has two isomers, 1-naphthol and 2-naphthol. Among them, 2-naphthol, also known as ethyl naphthol and β-naphthol, is an important organic chemical raw material and synthetic intermediate. 2-Naphthol can not only be used to produce dye intermediates such as R acid, butyric acid, and G phenol (2-naphthol-6,8-disulfophenol), but also can be used to prepare intermediates for ice-dyed dye naphthol AS 2,3-acid and direct dyes such as sun fast blue and gray date red. At the same time, 2-naphthol can also be used as antioxidant, rubber anti-aging agent and raw material of pesticide and medicine. 1-Naphthol, also known as methylnaphthol and α-naphthol, has been continuously developed and widely used in medicine, pesticides, dyes, spices, chiral catalyst synthesis, etc., resulting in increasing market demand and promising prospects. Its production method is similar to that of 2-naphthol and is an important isomer in the production of 2-naphthol.

The main methods of synthesizing naphthol are: sulfonated alkali fusion method, isopropyl naphthalene method, hydrolysis method, tetrahydronaphthalene method, electrochemical method, hydrogen peroxide method, etc. The sulfonated alkali fusion method is currently the main method for the industrial production of 2-naphthol at home and abroad, and the technology is relatively mature. This method uses refined naphthalene as a raw material, under the action of concentrated sulfuric acid, sulfonates to obtain naphthalenesulfonic acid, then neutralizes the resulting sodium salt with sodium sulfite, then melts it with NaOH alkali to obtain sodium naphthol, and then acidifies it with sulfuric acid to obtain crude naphthol. product. Due to the high energy consumption of the naphthalene sulfonation process and the production of a large amount of pollutants, it is difficult to control and has a serious impact on the environment.

There are two main techniques for hydrolysis: the chloronaphthalene method and the naphthylamine method. The chloronaphthalene method is to chlorinate naphthalene into chloronaphthalene under high temperature and high pressure conditions, then pass water vapor at 800°C, and hydrolyze the chloronaphthalene into naphthol under the action of catalysts CuCl and KCl. The naphthylamine method is to use nitric acid to nitrate and reduce naphthalene to obtain 1-naphthylamine, and then use dilute sulfuric acid as a medium to hydrolyze to obtain 1-naphthol. The technological process has defects such as severe equipment corrosion, large amount of wastewater treatment, and long technological process, and the intermediate naphthylamine is a recognized carcinogen with high toxicity.

The tetralin method is to convert naphthalene into tetralone by catalytic hydrogenation first; then use oxygen to catalytically oxidize it into tetralone in liquid phase, and then dehydrogenate it to generate 1-naphthol. The harsh reaction conditions of this method lead to high cost, and the raw material catalyst is expensive and lacks competitiveness. In a word, traditional synthetic methods are all multi-step reactions, and naphthol can be produced through a long process, resulting in a variety of intermediates, resulting in low utilization of atoms; at the same time, due to the generally poor selectivity of the reaction, A large amount of waste will inevitably be produced, resulting in higher costs, more pollutant discharge, and difficult treatment of pollution technology, which will have a serious impact on the environment.

Direct catalytic synthesis method: Catalytic synthesis method, as a new green synthesis process, has strong industrialization potential. Its basic idea is to directly synthesize naphthol from the source through one-step hydroxylation reaction of naphthalene under the action of a catalyst and an oxidizing agent, in order to simplify the reaction steps and reduce the reaction time. Intermediates, improve atom utilization. However, the industrialization of this method is still a long way off.

The isopropylnaphthalene method uses naphthalene as a raw material, and under the action of an alkylating agent, β-isopropylnaphthalene (β-IPN) is produced through catalytic isopropylation, and then β-IPNHP is produced by oxidation with molecular oxygen. Finally, acid decomposition yields 2-naphthol and acetone. Because the technology of propenyl naphthalene method is relatively complicated, it has the advantages of large-scale, high efficiency, cleanness, high atom utilization rate, and no pollution.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing mixed naphthols that is efficient, clean, high in atom utilization, and pollution-free.

The object of the present invention can be realized by following measure: the method comprises the purification of raw material-isopropyl naphthalene (IPN, isomerization, alkali washing, oxidation reaction, acid hydrolysis reaction, separation and naphthol rectification, make mixed naphthalene phenol;

Purification refers to the removal of a small amount of impurities in monoisopropylnaphthalene;

Isomerization refers to the conversion between α-isopropylnaphthalene and β-isopropylnaphthalene;

Alkali washing refers to the use of lye to wash the acidic substances in the raw material of isopropyl naphthalene;

Oxidation reaction refers to the oxidation of monoisopropylnaphthalene under alkaline conditions using molecular oxygen;

Acid hydrolysis reaction refers to the decomposition of isopropylnaphthalene hydroperoxide into naphthol and acetone under acidic conditions.

The isomerization of monoisopropylnaphthalene is carried out under acidic catalyst conditions, the alkylating agent is propylene, 2-butene, and the acidic catalyst is Lewis acid or H-type zeolite catalyst, preferably AlCl ₃ , HM hydrogen type mercerizing Zeolite, HY hydrogen type Y zeolite catalyst, the isomerization temperature is 120-350°C, preferably 180-270°C.

The target product of mixed naphthol is two kinds of 1-naphthol and 2-naphthol, and the ratio of the two is between 1:6-1:1, preferably 1:5-1:2. .

Said monoisopropyl naphthalene alkali washing, oxidation under alkaline conditions, the alkaline conditions are NaOH, Na ₂ C aqueous solution, the concentration range is 0.5%-3.5%, preferably 1.5%-2.5%;

The oxidation reaction temperature is 80-110°C, preferably 90-100°C; the ratio of the molar amount of oxygen-containing gas used in the reaction to the molar amount of monoisopropylnaphthalene in the feed is 20-60, preferably 40-50; The volume concentration can be 5-100%, preferably 15-50%. The cocatalyst is stearic acid, and the initiator is hydrogen peroxide, isobutyraldehyde or isopropylnaphthalene hydroperoxide.

The acid hydrolysis reaction is an inorganic acid, preferably: hydrochloric acid, sulfuric acid, perchloric acid, the catalyst concentration is 0.5-1.5%, the solvent is dodecane, acetonitrile, acetic acid, methanol, and the reaction temperature is 20-50°C.

The primary separation is oil-water two-phase separation; rectification and separation of the target product mixed naphthol.

The isomerization reaction is carried out in a stirred reactor or a fixed bed reactor at a temperature of 120-350°C, preferably 180-270°C. It can promote the conversion of α-alkylnaphthalene to β-alkylnaphthalene.

The oxidation reaction of isopropylnaphthalene is carried out under alkaline conditions. The oxidation is carried out by oxygen-containing gas containing molecular oxygen; the oxygen-containing gas is passed into the bottom of the reactor through the inlet pipe and added to the catalyst system. It can bubble evenly, which is conducive to the full contact between oxygen and reactants.

The present invention relates to reactors that can be produced in batch, semi-continuous and continuous ways, but semi-continuous or continuous ways are preferred.

Compared with the prior art, the present invention has the following advantages: the present invention has few pollutants in the technical process, less waste water discharge, can prepare two kinds of 1-naphthol and 2-naphthol, and the process can adjust the ratio of the product to To adapt to the demand of the market, the process can meet the needs of producing high-quality naphthol at the same time.

Description of drawings

Fig. 1 is the process flow chart of preparing mixed naphthols of the present invention.

Detailed ways

List 3 examples below, further illustrate the present invention, but the present invention is not limited to these examples.

According to the present invention, mixed naphthols are prepared from monoisopropylnaphthalene through processes such as isomerization, oxidation reaction, acid decomposition and rectification.

Example 1-1

Use monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, activate the HM mordenite catalyst for 2-3 hours at 500°C, and perform isomerization reaction at 270°C and 1MPa 3h, β-IPN/α-IPN=8:2, can modulate the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C, 1.5% NaOH aqueous solution is used as a catalyst, isobutyraldehyde is used as an initiator, and air is used as an oxidant. The content of IPNHP in the product increases significantly. After 10 hours, The selectivity of cumylnaphthalene hydroperoxide exceeds 60%. , IPNHP content reaches 13.4%. The oxidized product directly enters the decomposition reactor, and at normal temperature and pressure, HClO is used as a catalyst, AcOH is a solvent, and the reaction _is carried out for 1.5h. The yield of mixed naphthols is 93%, of which 2-naphthols account for 67.1%. 1-naphthol accounted for 22.6%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Embodiment 1-2: change oxidation process catalyst and reaction condition

Use monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, activate the HM mordenite catalyst for 2-3 hours at 500°C, and perform isomerization reaction at 270°C and 1MPa 3h, β-IPN/α-IPN=8:2, can modulate the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 90°C, with 0.5% NaOH aqueous solution as the catalyst, H ₂ O ₂ as the initiator, and air as the oxidant, the content of IPNHP (what is it called) in the product is obvious Rising, after 15h, the selectivity of hydroperoxide isopropyl naphthalene exceeded 56%. , IPNHP content reaches 12.1%. The oxidized product directly enters the decomposition reactor, and at normal temperature and pressure, _HClO is used as a catalyst, AcOH is a solvent, and the reaction is carried out for 1.5h. The yield of mixed naphthols is 90%, of which 2-naphthols account for 65.5%. 1-naphthol accounted for 21.6%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Embodiment 1-3: change catalyst and solvent of acid hydrolysis reaction

Use monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, activate the HM mordenite catalyst for 2-3 hours at 500°C, and perform isomerization reaction at 270°C and 1MPa 3h, β-IPN/α-IPN=8:2, can modulate the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C, 1.5% NaOH aqueous solution is used as a catalyst, H ₂ O ₂ is used as an initiator, and air is used as an oxidant. The content of IPNHP in the product increases significantly. After 15 hours , the selectivity of isopropylnaphthalene hydroperoxide exceeded 56%. , IPNHP content reaches 12.1%. The oxidized product directly enters the hydrolysis reactor, and at normal temperature and pressure, HCl is used as a catalyst, methanol is a solvent, and the reaction is 3.5h. The yield of mixed naphthols is 65%, of which 2-naphthols account for 65.0%, 1 -Naphthol accounted for 20.3%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Example 2-1

Use monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, activate the HY zeolite catalyst at 500°C for 2-3h, and perform isomerization reaction at 300°C and 1MPa for 3h , β-IPN/α-IPN=8:2, can modulate the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C and a 1.5% Na ₂ CO ₃ aqueous solution as a catalyst, isobutyraldehyde is used as an initiator, and air is used as an oxidant. The content of IPNHP in the product increases significantly. After 10 h, the selectivity of isopropylnaphthalene hydroperoxide exceeded 75%. , IPNHP content reaches 15.4%. The oxidized product directly enters the hydrolysis reactor, and at normal temperature and pressure, _HClO is used as a catalyst, AcOH is a solvent, and the reaction is carried out for 1.5h. The yield of mixed naphthols is 93%, of which 2-naphthols account for 67.1%. 1-naphthol accounted for 22.6%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Example 2-2: Changing the Initiator

Use monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, activate the HY zeolite catalyst at 500°C for 2-3h, and perform isomerization reaction at 300°C and 1MPa for 3h , β-IPN/α-IPN=8:2, can modulate the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C, 1.5% Na ₂ CO ₃ aqueous solution is used as a catalyst, isopropyl naphthalene hydroperoxide is used as an initiator, and air is used as an oxidant. The IPNHP in the product is Content obviously rises, and after 10h, the selectivity of cumyl hydroperoxide exceeds 75%. , IPNHP content reaches 15.4%. The oxidized product directly enters the decomposition reactor, and at normal temperature and pressure, HClO is used as a catalyst, AcOH is a solvent, and the reaction _is carried out for 1.5h. The yield of mixed naphthols is 93%, of which 2-naphthols account for 67.1%. 1-naphthol accounted for 22.6%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Example 3-1

Using monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, under the catalyst of AlCl3, isomerization reaction at 180°C and normal pressure for 3h, β-IPN/α-IPN =8.5:1.5, can adjust the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C, 1.5% NaOH aqueous solution is used as a catalyst, isobutyraldehyde is used as an initiator, and air is used as an oxidant. The content of IPNHP in the product increases significantly. After 10 hours, The selectivity of cumylnaphthalene hydroperoxide exceeds 75%. , IPNHP content reached 16.0%. The oxidized product directly enters the decomposition reactor, and at normal temperature and pressure, HClO is used as a catalyst, AcOH is a solvent, and _the reaction is 1.5h. The yield of mixed naphthols is 93%, of which 2-naphthols account for 68.% , 1-naphthol accounted for 22.5%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Embodiment 3-2: Change the content of oxygen-containing gas (oxygen, 100% content)

Using monoisopropylnaphthalene (IPN) as raw material, where β-IPN/α-IPN=7:3, under the catalyst of AlCl3, isomerization reaction at 180°C and normal pressure for 3h, β-IPN/α-IPN =8.5:1.5, can adjust the ratio of β-position and α-position, which is beneficial to the ratio of modulation products. After the mixture is washed with alkali, it enters the oxidation reactor. At a reaction temperature of 100°C, under the catalyst of 1.5% NaOH aqueous solution, with isobutyraldehyde as the initiator and oxygen as the oxidant, the content of IPNHP in the product increases significantly. After 10 hours, The selectivity of cumylnaphthalene hydroperoxide exceeds 75%. , IPNHP content reached 16.0%. The oxidized product directly enters the decomposition reactor, and at normal temperature and pressure, _HClO is used as a catalyst, AcOH is a solvent, and the reaction takes 1.5h. The yield of mixed naphthols is 93%, of which 1-naphthol accounts for 68.% , 1-naphthol accounted for 22.5%. The mixed naphthols can be separated into 1-naphthol and 2-naphthol through the separation process.

Claims (10)

1. A method for preparing mixed naphthols is characterized in that: the method comprises the purification, isomerization of raw material-isopropylnaphthalene, alkali washing, oxidation reaction, acid hydrolysis reaction, separation and naphthol rectification at the beginning, preparation Get mixed naphthols; Purification refers to the removal of a small amount of impurities in monoisopropylnaphthalene; Isomerization refers to the conversion between α-isopropylnaphthalene and β-isopropylnaphthalene; Alkali washing refers to the use of lye to wash the acidic substances in the raw material of isopropyl naphthalene; Oxidation reaction refers to the oxidation of monoisopropylnaphthalene under alkaline conditions using molecular oxygen; Acid hydrolysis reaction refers to the decomposition of isopropylnaphthalene hydroperoxide into naphthol and acetone under acidic conditions. 2. the method for preparing mixed naphthols according to claim 1 is characterized in that: described one isopropyl naphthalene isomerization reacts under acidic catalyst condition, and alkylating agent is propylene, 2-butene , the acidic catalyst is a Lewis acid or H-type zeolite catalyst, and the isomerization temperature is 120-350°C. 3. according to the method for claim 1 and 2 described preparation mixed naphthols, it is characterized in that: described one isopropyl naphthalene isomerization reacts under acidic catalyst condition, and alkylating agent is propylene, 2- For butene, the acidic catalyst is AlCl ₃ , HM hydrogen type mordenite or HY hydrogen type Y zeolite catalyst, and the isomerization temperature is 180-270°C. 4. the method for preparing mixed naphthol according to claim 1 is characterized in that: described mixed naphthol target product is two kinds of 1-naphthol and 2-naphthol, and the ratio of the two is 1:6- Between 1:1. 5. the method for preparing mixed naphthols according to claim 1 or 4, is characterized in that: described mixed naphthols object product is two kinds of 1-naphthols and 2-naphthols, and the ratio of the two is 1: 5-1:2. 6. prepare the method for mixing naphthol according to claim 1, it is characterized in that: described monoisopropyl naphthalene alkali washes, and oxidizes under alkaline condition, and alkaline condition is NaOH, Na ₂ CO ₃ aqueous solution, The concentration range is 0.5%-3.5%; the oxidation reaction temperature is 80-110°C; the ratio of the molar amount of oxygen-containing gas used in the reaction to the molar amount of monoisopropylnaphthalene in the feed is 20-60; the volume concentration of oxygen is 5-100%; cocatalyst is stearic acid, and initiator is hydrogen peroxide, isobutyraldehyde, or isopropylnaphthalene hydroperoxide. 7. the method for preparing mixed naphthols according to claim 1 or 6, is characterized in that: described monoisopropyl naphthalene alkali washing is oxidized under alkaline conditions, and alkaline conditions are NaOH, Na ₂ CO ₃ Aqueous solution, the concentration range is 1.5%-2.5%; the oxidation reaction temperature is 90-100 ° C; the ratio of the molar amount of oxygen-containing gas used in the reaction to the molar amount of monoisopropylnaphthalene in the feed is 40-50; the volume of oxygen The concentration is 15-50%. 8. prepare the method for mixing naphthol according to claim 1, it is characterized in that: described acid hydrolysis reaction is inorganic acid, catalyst concentration 0.5-1.5%, solvent is dodecane, acetonitrile, acetic acid, methyl alcohol, reaction The temperature is 20-50°C. 9. the method for preparing mixed naphthols according to claim 1 or 8, is characterized in that: described acid hydrolysis reaction is hydrochloric acid, sulfuric acid, perchloric acid. 10. The method for preparing mixed naphthols according to claim 1, characterized in that: the initial separation is oil-water two-phase separation; rectification separation purpose product mixed naphthols.

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