Method for preparation of o-nitrobenzoic acid by catalytic oxidation of o-nitrotoluene

A technology of o-nitrobenzoic acid and o-nitrotoluene, applied in the field of catalytic oxidation to prepare o-nitrobenzoic acid, can solve the problems of methanol and benzene solvent toxicity, high solvent toxicity, and equipment corrosion

Inactive Publication Date: 2015-01-28
王晓伟
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

She Yuanbin and others have reported that in the alkaline medium of methanol (Fine Chemical Industry, 1998, 1(15): 45~47), methanol-benzene (Fine Chemical Industry, 2004, 21(6): 474~478), the metal Phthalocyanine or metal porphyrin is a catalyzer, and catalytic oxygen oxidation o-nitrotoluene prepares the method for o-nitrobenzoic acid, and this method mainly solves traditional method (Tetrahedron Lett, 2003,44: 2053~2056.) The problem of equipment corrosion caused by medium acidic medium, but this method still has the problem of high solvent toxicity
[0006] Chinese patent CN1944396A (disclosure date: April 11, 2007) discloses a method for preparing o-nitrobenzoic acid by biomimetic catalytic oxygen oxidation of o-nitrotoluene, which uses ethanol-water solution as a solvent to further solve the above-mentioned method The problem of high toxicity of methanol and benzene solvents
[0007] Yang Fan et al. used Co(C 18 h 35 o 2 ) 2 / NH 4 Br is a catalyst, AIBN is a free radical initiator, and nitrobenzoic acid is synthesized, but only a small amount of ONBA can be obtained

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] In a 1000ml autoclave, add 200ml methanol, 200g o-nitrotoluene, 1.5g catalyst MnO 2 / RuO 4 (MnO 2 with RuO 4 The mass ratio is 1:1), under full stirring, oxygen is introduced. The reaction temperature was maintained at 100°C and the pressure at 0.1 MPa. After 12 hours, the reaction was stopped. Cool to room temperature, release the pressure, filter the catalyst, distill off the solvent methanol under reduced pressure, extract with ether-water, separate phases, wash the organic phase with water, and recover the solvent by distillation to obtain o-nitrobenzoic acid with a yield of 89.1% and a purity of More than 96%. The catalyst after filtering by o-nitro group can be recycled.

Embodiment 2

[0020] In the autoclave of 1000ml, add 200ml ethanol, 200g o-nitrotoluene, 2.0g catalyst MnO 2 / RuO 4 (MnO 2 with RuO 4 The mass ratio is 1.5:1), under full stirring, oxygen is introduced. The reaction temperature was maintained at 140° C. and the pressure at 0.5 MPa. After 10 hours, the reaction was stopped. Cool to room temperature, release the pressure, filter the catalyst, distill off the solvent methanol under reduced pressure, extract with ether-water, separate phases, wash the organic phase with water, and recover the solvent by distillation to obtain o-nitrobenzoic acid with a yield of 92.3% and a purity of More than 96%. The catalyst after filtering by o-nitro group can be recycled.

Embodiment 3

[0022] In a 1000ml autoclave, add 200ml methanol, 30g o-nitrotoluene, 0.5g catalyst MnO 2 / RuO 4 (MnO 2 , RuO 4 The mass ratio is 1:1), under full stirring, oxygen is introduced. The reaction temperature was maintained at 120° C. and the pressure at 1.5 MPa. After 6 hours, the reaction was stopped. Cool to room temperature, release the pressure, filter the catalyst, distill off the solvent methanol under reduced pressure, extract with ether-water, separate phases, wash the organic phase with water, and recover the solvent by distillation to obtain o-nitrobenzoic acid with a yield of 91.7% and a purity of More than 96%. The catalyst after filtering by o-nitro group can be recycled.

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PUM

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Abstract

The invention relates to a method for preparation of o-nitrobenzoic acid by catalytic oxidation, and the method comprises the following steps: adding a solvent, o-nitrotoluene, catalyst MnO2 and RuO4 into a high pressure reactor, introducing oxygen, reacting 5 to 15 hours at 100-150 DEG C under 0.1-2MPa, and after the reaction, filtering the catalyst, extracting, washing with water, and distilling to recover the solvent to obtain the o-nitrobenzoic acid. The filtered catalyst can be recycled.

Description

technical field [0001] The invention relates to a method for preparing o-nitrobenzoic acid, in particular to a method for preparing o-nitrobenzoic acid by catalytic oxidation. Background technique [0002] O-nitrobenzoic acid (ONBA) is an important intermediate for organic synthesis and preparation of dyes, medicines, pigments, spices, antioxidants for greases and lubricating oils, and metal rust inhibitors. [0003] As early as the 1980s, Sasson et al. used PTC-RuO 4 -NaClO oxidation method synthesized ONBA, and its yield was as high as 95%, but this method is not only costly, but also the chloride ions generated in the reaction will cause serious corrosion to the equipment, so it is difficult to industrialize. At present, only a small amount of ONBA can be produced by oxidizing ONT by stoichiometric oxidation methods (potassium permanganate oxidation, sodium dichromate oxidation, etc.) that are highly polluting and costly. [0004] Saw atari et al. recently reported the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/12C07C205/57B01J23/656
CPCY02P20/584
Inventor 王晓伟
Owner 王晓伟
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