阅读说明：本技术 一种清洁高效的1,6和1,7-克利夫酸制备方法 (Clean and efficient preparation method of 1,6 and 1, 7-clevuric acid ) 是由 陈兴鹏 冯传密 武金丹 吴昊 王聪 刘新伟 王元平 杨克俭 霍瑜姝 于 2020-08-14 设计创作，主要内容包括：本发明提供了一种清洁高效的1,6和1,7-克利夫酸制备方法,包括：5-硝基-2-萘磺酸镁盐和8-硝基-2-萘磺酸镁盐混合物水溶液在催化剂作用下发生加氢还原反应,得到5-氨基-2-萘磺酸镁盐和8-氨基-2-萘磺酸镁盐水溶液；还原后的混合液滤除催化剂,然后将剩余溶液浓缩至40～120g/L结晶,优选的浓缩至60～80g/L,然后进行过滤,得到的滤饼为5-氨基-2-萘磺酸镁盐(1,6-克利夫酸镁盐),滤液为8-氨基-2-萘磺酸镁盐(1,7-克利夫酸镁盐)溶液；分别在滤液及滤饼中加酸进行酸析得到1,6-克利夫酸和1,7-克利夫酸。本发明提供的制备方法,避免产生大量的铁泥和重金属污染,实现了环境友好,无废弃物产生,减少了环境污染,且提高了产品收率,产品收率可达85～99％。(The invention provides a clean and efficient preparation method of 1,6 and 1, 7-clevuric acid, which comprises the following steps: carrying out hydrogenation reduction reaction on a mixture aqueous solution of 5-nitro-2-naphthalene sulfonic acid magnesium salt and 8-nitro-2-naphthalene sulfonic acid magnesium salt under the action of a catalyst to obtain a 5-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution and a 8-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution; filtering the reduced mixed solution to remove the catalyst, concentrating the residual solution to 40-120 g/L of crystals, preferably to 60-80 g/L, and then filtering to obtain a filter cake which is a magnesium 5-amino-2-naphthalenesulfonate (magnesium 1, 6-cliff acid) and a filtrate which is a magnesium 8-amino-2-naphthalenesulfonate (magnesium 1, 7-cliff acid) solution; and respectively adding acid into the filtrate and the filter cake for acid precipitation to obtain the 1, 6-clevuric acid and the 1, 7-clevuric acid. The preparation method provided by the invention avoids the generation of a large amount of iron mud and heavy metal pollution, realizes environmental friendliness, avoids the generation of waste, reduces the environmental pollution, improves the product yield, and can reach 85-99%.)

1. A clean and efficient preparation method of 1,6 and 1, 7-clevuric acid is characterized in that: the method comprises the following steps:

(1) reduction reaction

Carrying out hydrogenation reduction reaction on a mixture aqueous solution of 5-nitro-2-naphthalene sulfonic acid magnesium salt and 8-nitro-2-naphthalene sulfonic acid magnesium salt under the action of a catalyst to obtain a 5-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution and a 8-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution;

(2) concentrating and separating

Filtering the catalyst from the mixed solution reduced in the step (1), concentrating the residual solution to 40-120 g/L for crystallization, and then filtering to obtain a filter cake which is a 5-amino-2-naphthalene magnesium sulfonate (1, 6-magnesium clevuide) solution, and a filtrate which is a 8-amino-2-naphthalene magnesium sulfonate (1, 7-magnesium clevuide) solution;

(3) acid precipitation

Respectively adding acid into the 5-amino-2-naphthalenesulfonic acid magnesium salt (1, 6-cliff acid magnesium salt) and 8-amino-2-naphthalenesulfonic acid magnesium salt (1, 7-cliff acid magnesium salt) solution obtained after filtering in the step (2), and adjusting the pH value to 1-3 to obtain 5-amino-2-naphthalenesulfonic acid (1, 6-cliff acid) and 8-amino-2-naphthalenesulfonic acid (1, 7-cliff acid).

2. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the catalyst in the step (1) is a supported catalyst or a Raney nickel catalyst.

3. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid according to claim 2, characterized by: the supported catalyst is a supported catalyst containing Pd and Pt, and the carrier is one of active carbon, silicon dioxide and alumina.

4. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid according to claim 2, characterized by: the Raney nickel catalyst is a Raney nickel catalyst without doping or doping Fe or doping Cr.

5. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the acid in the step (3) is dilute sulfuric acid.

6. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the dosage of the catalyst in the step (1) is 1-20 percent of the total mass of the 5-nitro-2-naphthalene sulfonic acid magnesium salt and the 8-nitro-2-naphthalene sulfonic acid magnesium salt, and is preferably 5-10 percent.

7. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the reaction temperature in the step (1) is 60-150 ℃, and preferably 80-120 ℃.

8. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the reaction pressure in the step (1) is 0.5-8.0 MPa, preferably 1.0-3.0 MPa.

9. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: the reaction time of the step (1) is 0.1-5 h, preferably 0.5-2 h.

10. A clean and efficient process for the preparation of 1,6 and 1, 7-clevuric acid as claimed in claim 1, characterized by: and (2) concentrating the mixed solution to 60-80 g/L.

Technical Field

The invention belongs to the field of dye intermediate synthesis, and particularly relates to a clean and efficient preparation method of 1,6 and 1, 7-clevuric acid.

Background

The Clifac comprises three different products of 1, 6-Clifac, 1, 7-Clifac and mixed Clifac, which are all very important dye intermediates. Wherein the 1, 6-Clifac is used for preparing azo dyes and sulfur dyes, such as direct fast blue BGL, sulfur blue CV, direct fast red RGL, direct black 80, and the like; the 1, 7-Clifac is mainly used for preparing direct fast blue B2R, BGL, gray LBN, brown RTL, sulfide salt CD and the like; the mixed clevuric acid can be used for producing direct black FF and the like. The dyes generated by the products have various varieties, wide application, large market demand and high economic value.

The dye production process compilation mentions that the conventional production process of 1, 6-and 1, 7-clevuric acid is mainly carried out by the following method: the refined naphthalene is sulfonated to obtain 2-naphthalenesulfonic acid, and then is nitrified in a sulfuric acid medium to generate a mixed solution of 5-nitro-2-naphthalenesulfonic acid and 8-nitro-2-naphthalenesulfonic acid. The mixed solution containing waste acid is neutralized by dolomite powder, calcium sulfate solid is filtered out, the obtained nitronaphthalene magnesium sulfonate mixture is reduced by iron powder to obtain mixed aminonaphthalene magnesium sulfonate, the solubility difference of two isomer magnesium salts at a certain temperature is utilized for separation, the separation is carried out by acid precipitation respectively to obtain 1, 6-Clifac and 1, 7-Clifac, and the total yield of the Clifac is 56%.

Patent CN107602422A describes that 1.4-2 equivalents of hydrazine hydrate solution is used to replace iron powder for reduction to prepare mixed clevus acid, and the reaction requires 6-8% of one or more of ferric hydroxide, ferric trichloride and ferric peroxide as catalyst. And after the reduction reaction, adding magnesium oxide for neutralization, adjusting the pH value to 7-8, then concentrating the neutralized solution, adding 55% sulfuric acid for acidification, stirring, filtering and washing to obtain 1,6 and 1,7 mixed clevus acid.

It can be known from the above that, the reduction reaction in the conventional process is implemented by using iron powder under an acidic condition, and although the process is simple, a large amount of iron mud containing organic matters and salt-containing wastewater are generated, which not only makes the post-treatment difficult and the cost high, but also causes a large amount of waste to seriously pollute the environment and has great environmental protection pressure. In the patent (CN 107602422A), hydrazine hydrate solution is used for replacing iron powder, although the process avoids the production of iron mud slag, hydrazine hydrate belongs to highly toxic chemicals and has carcinogenicity and strong corrosivity, so that the hydrazine hydrate is not a particularly ideal clean raw material, and the mixed Clifv acid is not separated. Therefore, there is a great need to provide an environmentally friendly, economical, clean and efficient process for the preparation and isolation of 1, 6-and 1, 7-clevuric acids.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a clean and efficient preparation method of 1, 6-and 1, 7-clevuric acid, which is environment-friendly, does not generate wastes, and simultaneously improves the reduction efficiency.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a clean and efficient preparation method of 1,6 and 1, 7-clevuric acid, which comprises the following steps:

(1) reduction reaction

Carrying out hydrogenation reduction reaction on a mixture aqueous solution of 5-nitro-2-naphthalene sulfonic acid magnesium salt and 8-nitro-2-naphthalene sulfonic acid magnesium salt under the action of a catalyst to obtain a 5-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution and a 8-amino-2-naphthalene sulfonic acid magnesium salt aqueous solution;

(2) concentrating and separating

Filtering the catalyst from the mixed solution reduced in the step (1), concentrating the residual solution to 40-120 g/L of crystals, preferably to 60-80 g/L, and then filtering to obtain a filter cake which is a 5-amino-2-naphthalene sulfonic acid magnesium salt (1, 6-cliff acid magnesium salt) and a filtrate which is a 8-amino-2-naphthalene sulfonic acid magnesium salt (1, 7-cliff acid magnesium salt) solution;

(3) acid precipitation

Respectively adding acid, preferably dilute sulfuric acid, into the 5-amino-2-naphthalenesulfonic acid magnesium salt (1, 6-cliff acid magnesium salt) and 8-amino-2-naphthalenesulfonic acid magnesium salt (1, 7-cliff acid magnesium salt) solution obtained after filtration in the step (2), adjusting the pH to 1-3, and then respectively obtaining 5-amino-2-naphthalenesulfonic acid (1, 6-cliff acid) and 8-amino-2-naphthalenesulfonic acid (1, 7-cliff acid) through filtration, washing and drying.

Further, the catalyst in the step (1) is a supported catalyst or a Raney nickel catalyst.

Furthermore, the supported catalyst is a supported catalyst containing Pd and Pt, and the carrier is one of activated carbon, silicon dioxide and alumina.

Further, the raney nickel catalyst is undoped or doped with Fe or Cr.

Further, the dosage of the catalyst in the step (1) is 1-20% of the total mass of the 5-nitro-2-naphthalene sulfonic acid magnesium salt and the 8-nitro-2-naphthalene sulfonic acid magnesium salt, preferably 5-10%.

Further, the reaction temperature of the step (1) is 60-150 ℃, and preferably 80-120 ℃.

Further, the reaction pressure in the step (1) is 0.5 to 8.0MPa, preferably 1.0 to 3.0 MPa.

Further, the reaction time of the step (1) is 0.1-5 h, preferably 0.5-2 h.

Compared with the prior art, the clean and efficient preparation method of the 1,6 and 1, 7-clevuric acid provided by the invention has the following advantages:

(1) the hydrogen is used for replacing the traditional iron powder for reduction, so that the generation of iron mud slag which is difficult to treat is effectively avoided, the environment friendliness is realized, no waste is generated, and the environmental pollution is reduced;

(2) the catalyst in the reduction reaction can be recycled, so that the production cost is reduced, and the economic benefit is improved;

(3) the reduction efficiency is obviously improved, and the yield can reach 85-99%.

Detailed Description

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

The mixture of the raw material of magnesium 5-nitro-2-naphthalenesulfonate and magnesium 8-nitro-2-naphthalenesulfonate was prepared as follows:

adding 16g of naphthalene into a sulfonation reaction pot, heating to 120 ℃, and slowly adding 15.75g of 98% concentrated sulfuric acid into a reaction system within 40min after the naphthalene is completely melted. The system was then warmed to 162 ℃ and the reaction was continued at this temperature for one and a half hours. After the reaction, the temperature is reduced to 120 ℃, and 21.85g of 98% concentrated sulfuric acid is continuously and slowly added into the system. Then the temperature of the system is reduced to about 32 ℃, 12.74g of 68 percent concentrated nitric acid is slowly added, the temperature is controlled to about 36 ℃ during the adding process, and then the reaction is continued for 1 hour at the temperature. Adding 50mL of water into the nitrified liquid system after reaction, heating to 91-95 ℃, and removing the nitre for 2 hours. Diluting the solution after nitrate removal by adding 100mL of water, adding a mixture of calcium oxide and magnesium oxide for neutralization until the pH value is 7-8, filtering, removing calcium sulfate, and reserving the filtrate as a mixed magnesium nitrosulfonate solution for a reduction reaction. The magnesium salt of 5-nitro-2-naphthalenesulfonic acid and the magnesium salt of 8-nitro-2-naphthalenesulfonic acid in the subsequent comparative examples and examples were prepared in the same manner as described above.

The overall yield is calculated by the formula:

wherein: m1 and M1 are the mass and molecular weight of the mixed magnesium nitronaphthalenesulfonate respectively;

m2 and M2 are respectively the mass and molecular weight of 1, 6-clevuric acid;

m3 and M3 are respectively the mass and molecular weight of 1, 7-clevuric acid.