Method of preparing 2-nitro-4-methylsulfonyl benzoic acid

A technology of thiamphenicol benzoic acid and thiamphenicol toluene, which is applied in the fields of chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problem that liquid-phase air oxidation is difficult to apply to industrial production, requires high equipment and technology, and is difficult Large-scale application and other issues, to achieve the effect of large industrial practical value, increase reaction yield, and easy control of reaction conditions

Active Publication Date: 2015-04-29
SHENYANG RES INST OF CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The liquid-phase air oxidation method has attracted widespread attention because of its environmental friendliness and low cost. However, this method has low reaction yield and high equipment and process requirements, making it difficult to apply on a large scale.
[0005] In summary, the current chemical oxidation method has mild reaction conditions and is easy to control, but it faces many problems in actual production; liquid-phase air oxidation is currently difficult to apply in industrial production

Method used

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  • Method of preparing 2-nitro-4-methylsulfonyl benzoic acid

Examples

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Effect test

Embodiment 1

[0027] In a 500mL reaction kettle equipped with a self-priming stirrer, add 140g 75% sulfuric acid, 20g 2-nitro-4-thiamphenicol toluene, 0.4g V 2 o 5 Stir and dissolve, close the system, connect the oxygen storage tank, adjust the stirring speed so that the gas holdup (volume) in the reaction solution reaches 15%, gradually heat up to 138-140°C, add 60g of 50% nitric acid to the system within 5-6 hours, and simultaneously Supplement oxygen to the system to keep the system pressure at 5×10 -3 MPa, react for 3 hours, and when the content of 2-nitro-4-thiamphenicol toluene is traced by liquid chromatography 98%. The filtrate was recovered and applied mechanically, 2-nitro-4 - The yield of thiamphenicol benzoic acid reaches 96.7% (calculated as 2-nitro-4-thiamphenicol toluene). 1g of product produces 6g of waste water, no waste gas and waste residue

Embodiment 2

[0029] 210g 75% sulfuric acid, 30g 2-nitro-4-thiamphenicol toluene, 0.3g V 2 o 5 Add it into a closed reaction kettle with a self-priming stirrer, stir and feed oxygen, adjust the temperature to 155°C, and adjust the stirring rate to make the gas holdup (volume) in the reaction solution reach 15%; add 90g of concentration dropwise 50% nitric acid, add it dropwise for 6 hours, add oxygen to the system as the reaction progresses, and keep the system pressure at 5×10 -3 MPa. The reaction speed is controlled by adjusting the nitric acid dropping rate and the gas-liquid ratio. After 2 hours of reaction after dropping, the liquid chromatography traces the content of 2-nitro-4-thiamphenicol toluene 98%. - The yield of 4-thiamphenicol benzoic acid was 88.7%.

Embodiment 3

[0031] 70g 75% sulfuric acid, 10g 2-nitro-4-thiamphenicol toluene, 1g V 2 o 5 Add it into a closed reaction kettle with a self-priming stirrer, stir and feed oxygen, adjust the temperature to 140°C, and adjust the stirring speed to make the gas holdup (volume) in the reaction solution reach 15%; add 30g concentration dropwise For 70% nitric acid, add dropwise for 7h. As the reaction proceeds, oxygen is added to the system to keep the system pressure at 5×10 -3 MPa. The reaction rate was controlled by adjusting the nitric acid drop rate and gas-liquid ratio. After 3 hours of reaction after the dropwise addition, when the content of 2-nitro-4-thiamphenicol toluene is traced by liquid chromatography 98%, and the filtered mother liquor is recovered and applied mechanically. - The yield of 4-thiamphenicol benzoic acid was 90.6%.

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Abstract

The invention discloses a novel method of preparing 2-nitro-4-methylsulfonyl benzoic acid. The target product which is 2-nitro-4-methylsulfonyl benzoic acid is prepared by carrying out reaction by adopting an oxidation reaction device with a self-priming stirrer, wherein 2-nitro-4-methylsulfonyltoluene is used as the raw material, sulfuric acid is used as a reaction medium, a transition metal oxide is used as the catalyst, and oxygen is introduced in the course of reaction. The method provided by the invention has the advantage that the reaction condition is easy to control, the production cost is low, and the amount of the generated three wastes is reduced.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for preparing 2-nitro-4-thiamphenicol benzoic acid. Background technique [0002] 2-Nitro-4-methylsulfonylbenzoic acid (2-Nitro-4-methylsulfonylbenzoic acid; NMSBA for short) is an important intermediate in organic synthesis and has great application value in the production of dyes, medicines and pesticides. Especially in terms of pesticides, it is an important intermediate for the synthesis of mesotrione. Mesotrione belongs to triketone herbicides, and is a highly effective special herbicide for corn fields, which has been widely used in developed countries. Due to the immature synthesis process of 2-nitro-4-thiamphenicol benzoic acid in China, the domestic application of mesotrione is limited. Therefore the improvement to the synthetic technology of 2-nitro-4-thiamphenicol benzoic acid appears very urgent. [0003] The oxidation methods for the direct preparation of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C317/44C07C315/04
Inventor 单体育刘红翼郑玉安祁巍王雪梅
Owner SHENYANG RES INST OF CHEM IND
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