阅读说明：本技术 一种2，6-二羟基甲苯的合成方法 (Synthesis method of 2, 6-dihydroxytoluene ) 是由 邵新华 徐保华 徐亚华 何正江 王荣洲 于 2020-06-02 设计创作，主要内容包括：一种2,6-二羟基甲苯的合成方法,将3-氯-2-甲基苯酚、甲酸钠溶液、氯化亚铜、保险粉、片碱溶液加入高压釜,氮气置换,升温于195～200℃保温1.5小时,降温至110℃压料至酸化釜,并用水洗釜后得到碱熔液,合并至酸化釜。在酸化釜内的碱熔液加水,滴加盐酸至PH2-3,降温至30℃,过滤,滤液加氯化钠,乙酸乙脂搅拌；静置分层,其中分去水层,有机层用75％碳酸钠溶液搅拌洗涤,继续静置分层,分去水层；有机相脱去乙酸乙脂,加甲苯脱水,降温离心加水,精制得成品。本发明合成工艺合理,成本低,生产过程中产生的水层(即废水)通过蒸馏后回收,节约了生产成本,废气通过冷凝回收,极大的减少了对环境的污染,保护了环境。(A synthetic method of 2, 6-dihydroxytoluene comprises the steps of adding 3-chloro-2-methylphenol, a sodium formate solution, cuprous chloride, sodium hydrosulfite and a caustic soda flake solution into an autoclave, replacing with nitrogen, heating to 195-200 ℃, keeping the temperature for 1.5 hours, cooling to 110 ℃, pressing to an acidification kettle, washing the kettle with water to obtain an alkali solution, and combining the alkali solution and the acidification kettle. Adding water into the alkali melt in the acidification kettle, dropwise adding hydrochloric acid to reach the pH value of 2-3, cooling to 30 ℃, filtering, adding sodium chloride and ethyl acetate into the filtrate, and stirring; standing for layering, wherein a water layer is removed, an organic layer is stirred and washed by a 75% sodium carbonate solution, and is continuously stood for layering, and a water layer is removed; removing ethyl acetate from the organic phase, adding toluene for dehydration, cooling, centrifuging, adding water, and refining to obtain the final product. The invention has reasonable synthesis process and low cost, the water layer (namely the waste water) generated in the production process is recovered after distillation, the production cost is saved, and the waste gas is recovered by condensation, thereby greatly reducing the pollution to the environment and protecting the environment.)

1. A method for synthesizing 2, 6-dihydroxytoluene is characterized by comprising the following steps:

1) adding 40-45 parts of 3-chloro-2-methylphenol, 1-3 parts of sodium formate solution, 1-3 parts of cuprous chloride, 0.1-0.5 part of sodium hydrosulfite and 50-60 parts of caustic soda flake solution into an autoclave, replacing with nitrogen, heating to 195-200 ℃, keeping the temperature for 1.5 hours, cooling to 110 ℃, pressing to an acidification kettle, washing the kettle with water to obtain alkaline solution, and combining the alkaline solution and the acidification kettle;

2) adding water into the alkali melt in the acidification kettle, dropwise adding hydrochloric acid to reach the pH value of 2-3, cooling to 30 ℃, filtering, adding sodium chloride and ethyl acetate into the filtrate, and stirring; standing for layering, wherein a water layer is removed, an organic layer is stirred and washed by a 75% sodium carbonate solution, and is continuously stood for layering, and a water layer is removed; removing ethyl acetate from the organic phase, adding toluene for dehydration, cooling, centrifuging, adding water, and refining to obtain the final product.

2. The method for synthesizing 2, 6-dihydroxytoluene according to claim 1, wherein the sodium hydrosulfite in step 1) is sodium sulfite.

3. The method for synthesizing 2, 6-dihydroxytoluene according to claim 1, characterized in that the water layer in the step 2) is subjected to distillation to recover ethyl acetate.

4. The method for synthesizing 2, 6-dihydroxytoluene according to claim 1, wherein the refining step in step 2) is performed by activated carbon and hydrothermal filtration, crystallization, centrifugation and drying to obtain the final product.

Technical Field

The invention relates to the technical field of chemical material preparation, in particular to a synthetic method of 2, 6-dihydroxytoluene.

Background

2, 6-dihydroxytoluene is an important fine chemical intermediate and is widely used in the fields of pigments, dyes, hair dyes, synthetic resins, medicines, pesticides, photography and the like. The preparation method of the 2, 6-dihydroxytoluene mainly comprises the following steps: a. a toluene diamine hydrolysis method; b. by passing 1, 3-cyclohexanedione through CH₃I or Mannich reaction introduces methyl at position 2 and then dehydrogenates; c. the resorcinol and the methanol are directly reacted to obtain the resorcinol-methanol solid solution; d. introducing tert-butyl into 4, 6-position of resorcinol, alkylating 2-position of formaldehyde by high-pressure catalytic hydrogenation, and removing tert-butyl. The cost of the methods is too high, and the practical operation of the methods is difficult, so that the methods cannot meet the requirements of industrial production.

Disclosure of Invention

The present invention is directed to a method for synthesizing 2, 6-dihydroxytoluene, which solves the above problems of the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: a method for synthesizing 2, 6-dihydroxytoluene comprises the following steps:

1) adding 40-45 parts of 3-chloro-2-methylphenol, 1-3 parts of sodium formate solution, 1-3 parts of cuprous chloride, 0.1-0.5 part of sodium hydrosulfite and 50-60 parts of caustic soda flake solution into an autoclave, replacing with nitrogen, heating to 195-200 ℃, keeping the temperature for 1.5 hours, cooling to 110 ℃, pressing to an acidification kettle, washing the kettle with water to obtain alkaline solution, and combining the alkaline solution and the acidification kettle;

2) adding water into the alkali melt in the acidification kettle, dropwise adding hydrochloric acid to reach the pH value of 2-3, cooling to 30 ℃, filtering, adding sodium chloride and ethyl acetate into the filtrate, and stirring; standing for layering, wherein a water layer is removed, an organic layer is stirred and washed by a 75% sodium carbonate solution, and is continuously stood for layering, and a water layer is removed; removing ethyl acetate from the organic phase, adding toluene for dehydration, cooling, centrifuging, adding water, and refining to obtain the final product.

Preferably, the sodium hydrosulfite in the step 1) is sodium sulfite.

Preferably, the water layer in the step 2) is subjected to a distillation still to recover ethyl acetate.

Preferably, the refining step in step 2) is to obtain a finished product by performing hydrothermal filtration on activated carbon, crystallizing, centrifuging and drying.

The invention has reasonable synthesis process and low cost, the water layer (namely the waste water) generated in the production process is recovered after distillation, the production cost is saved, and the waste gas is recovered by condensation, thereby greatly reducing the pollution to the environment and protecting the environment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.