Co-production method of 3-nitro-2-methylbenzoic acid and 3-nitrophthalic acid

A technology of nitrophthalic acid and toluic acid, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve problems such as serious environmental pollution, difficult post-processing, large amount of waste water and salt , to achieve the effects of small amount of waste salt, easy concentration, recovery and application, and great economic benefits

Active Publication Date: 2020-07-03
JIANGSU YONGAN CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, the filtered mother liquor obtained in the present invention can be applied mechanically, and can solve the problems of large amount of waste water and salt, difficult post-treatment, and serious environmental pollution existing in the existing process

Method used

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  • Co-production method of 3-nitro-2-methylbenzoic acid and 3-nitrophthalic acid
  • Co-production method of 3-nitro-2-methylbenzoic acid and 3-nitrophthalic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] (1) Add 3-nitro-o-xylene (100 g) and 10% nitric acid (600 g) into the oxidation reaction kettle, raise the temperature to 145-150 ° C, pass oxygen pressure 3.5-4.0 MPa, and keep stirring for 8 hours;

[0042](2) Cool down to 75-80°C and filter while hot to obtain 55 grams of crude 3-nitro-2-methylbenzoic acid, the weight of the filtrate is 650 g, and the concentration of nitric acid is 4.5%;

[0043] (3) The filter cake is washed with 11 g of 80°C water, and the washing liquid is combined with the filtrate of step (2) to be oxidized in an oxidation tank. After washing with water, the filter cake weighed 46 g, added 46 g of anhydrous methanol, heated to 65°C to dissolve, filtered out the insoluble matter while it was hot, cooled the filtrate to crystallize, kept at 15-20°C for 1 hour, filtered and dried to obtain 3-nitro-2- The finished product of methyl benzoic acid is 36 g (HPLC: 98.2%, content: 99.0%).

[0044] (4) The filtrate obtained in step (2) is placed in an ox...

Embodiment 2

[0048] (1) 3-Nitro-o-xylene (100 g), the filtrate (500 g, nitric acid concentration 18.5%) obtained in step (5) of Example 1 was added to the oxidation reaction kettle, the temperature was raised to 135-145 ° C, and the oxygen pressure was 2.5 -3.0 MPa, heat preservation and stirring reaction for 6 hours;

[0049] (2) Cool down to 70-75°C and filter while hot to obtain 73.7 grams of crude 3-nitro-2-methylbenzoic acid, the weight of the filtrate is 520 g, and the concentration of nitric acid is 12.0%;

[0050] (3) The filter cake was washed with 73 g of water at 65-70°C, and the washing liquid was collected. After washing with water, weigh 55 g of the filter cake, add 66 g of methanol (methanol / water = 80:20), heat up to 65°C to dissolve, filter out the insoluble matter while it is hot, cool the filtrate to crystallize, keep it at 10-15°C for 1 hour, filter and dry Obtained 45.2 g of 3-nitro-2-methylbenzoic acid (HPLC: 98.5%, content: 99.2%).

[0051] (4) The filtrate obtaine...

Embodiment 3

[0055] (1) 3-Nitro-o-xylene (100 g), take the filtrate (400 g, nitric acid concentration 23.5%) obtained from step (5) of Example 2 and add it to the oxidation reaction kettle, raise the temperature to 130-135 ° C, and pass the oxygen pressure 2.0-2.5 MPa, keep stirring and react for 3 hours;

[0056] (2) Cool down to 85-90°C and filter while hot to obtain 30.9 grams of crude 3-nitro-2-methylbenzoic acid, the weight of the filtrate is 460 g, and the concentration of nitric acid is 17.5%;

[0057] (3) The filter cake was washed with 61.8 g of water at 60-65°C, and the washing liquid was collected. After washing with water, weigh 20 g of the filter cake, add 40 g of methanol (methanol / water = 90:10), heat up to 65°C to dissolve, filter out the insoluble matter while it is hot, cool the filtrate to crystallize, keep it at 0-5°C for 1 hour, filter and dry 12.2 g of 3-nitro-2-methylbenzoic acid was obtained (HPLC: 98.6%, content: 99.3%).

[0058] (4) The filtrate obtained in step...

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Abstract

The invention discloses a co-production method of 3-nitro-2-methylbenzoic acid and 3-nitrophthalic acid. The co-production method comprises the following steps: (1) oxidizing 3-nitro-o-xylene into 3-nitro-2-methylbenzoic acid in nitric acid in the presence of a catalyst and an initiator by using oxygen as an oxidant; (2) after the reaction is finished, filtering the reaction product when the reaction product is still hot to obtain a 3-nitro-2-methylbenzoic acid crude product and mother liquor; (3) re-crystallizing the 3-nitro-2-methylbenzoic acid crude product to obtain a 3-nitro-2-methylbenzoic acid finished product; and (4) further oxidizing the mother liquor obtained in the step (2) to prepare 3-nitro-phthalic acid, cooling and filtering to obtain a 3-nitrophthalic acid crude product after the reaction is finished, applying the obtained filtrate to the step of oxidizing 3-nitrophthalic acid, and re-crystallizing the obtained crude product to obtain the 3-nitrophthalic acid finishedproduct. The problems of large amount of waste water and waste salt, difficult post-treatment and serious environmental pollution in the existing process are solved.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and relates to the synthesis of pesticide methoxyfenozide, antineoplastic drugs lenalidomide, pomalidomide, and antihypertensive drugs, in particular to a kind of 3-nitro-2-formazol Co-production method of benzoic acid and 3-nitrophthalic acid. Background technique [0002] 3-Nitro-2-methylbenzoic acid is an important raw material for the pesticide methoxyfenozide and the antineoplastic drug lenalidomide. Previously, a method for preparing it from 3-nitro-o-xylene through oxidation reaction has been reported in the literature . [0003] For example, Chinese patent CN109384667A discloses a method for preparing 3-nitro-2-methylbenzoic acid with nitric acid (concentration: 55%) as an oxidizing agent. After the reaction is completed, the crude product can be obtained by cooling and filtering, and the crude product is crystallized with 95% ethanol to obtain the product . Chinese patent CN...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/57C07C201/12C07C201/16
CPCC07C201/12C07C201/16C07C205/57
Inventor 耿敬坤方浙能厉大双赵静静荀卫利杜开云朱言华
Owner JIANGSU YONGAN CHEM CO LTD
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