Method for recycling acid in synthesis of 2-nitro-4-methylsulfonylbenzoic acid

A technology for thiamphenicol benzoic acid and acid recovery, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve unfavorable industrialized production, safe and stable progress, restriction of enterprise and social and economic development, existence safety and environmental protection Risk and other issues, to achieve the effect of solving safety and environmental risks, solving difficult to handle, and reducing the unit consumption of raw materials

CN111302984AActive Publication Date: 2020-06-19利民化学有限责任公司

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Patent Information

Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner: 利民化学有限责任公司
Publication Date: 2020-06-19

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Abstract

The invention relates to a method for recycling acid in synthesis of 2-nitro-4-methylsulfonylbenzoic acid, which comprises the following steps of 1) by using 4-methylsulfonyltoluene as a raw material,carrying out nitration reaction and oxidation reaction in a concentrated sulfuric acid medium, filtering dilute acid mother liquor obtained after the 2-nitro-4-methylsulfonylbenzoic acid crude product, and concentrating to obtain recycled acid, 2) recycling the recovered acid, and removing the reaction by-product polynitro compound from the dilute acid mother liquor by adopting a resin adsorptionmethod, so that the content of the polynitro compound in the dilute acid mother liquor after adsorption is less than 200 ppm, 3) concentrating the adsorbed dilute acid mother liquor, applying the concentrated dilute acid mother liquor to the nitration reaction, and supplementing the required catalyst to continue the oxidation reaction after the nitration reaction is finished, and 4) desorbing andregenerating the adsorbed resin through solvent desorption, concentrating, filtering and washing to recover the reaction by-product, thereby avoiding the safety and environmental protection risks caused by continuous accumulation of the by-product concentration in the synthesis process, and being safe, practical, green and environment-friendly, and suitable for industrial implementation.

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Description

technical field

[0001] The invention relates to a method for synthesizing 2-nitro-4-thiamphenicol benzoic acid, in particular to a method for recycling acid in the synthesis of 2-nitro-4-thiamphenicol benzoic acid. Background technique

[0002] 2-Nitro-4-thiamphenicolbenzoic acid, also known as o-nitro-4-thiamphenicolbenzoic acid, English name is 2-Nitro-4-methylsulfonylbenzoic acid, CAS number is 110964-79-9. 2-Nitro -4-Thiamphenicol benzoic acid is an important intermediate in the production of the herbicide mesotrione, and is widely used in the production of dyes, medicines and pesticides. Industrial production mostly uses 4-thiamphenicol toluene as raw material, nitration reaction in concentrated sulfuric acid medium to obtain 2-nitro-4-thiamphenicol toluene, and then oxidation reaction of 2-nitro-4-thiamphenicol toluene The crude product of 2-nitro-4-thiamphenicol benzoic acid is obtained, and the finished product of 2-nitro-4-thiamphenicol benzoic acid is obtained thr...

Claims

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