Production method for 2-nitrobenzyl bromide

The technology of an o-nitrobenzyl bromide and a production method is applied in the production field of the o-nitrobenzyl bromide, can solve the problems of large environmental pollution, high production cost, low yield and the like, achieves simple post-processing, improves reaction conversion rate, low cost effect

Active Publication Date: 2014-03-19
SHANDONG XINGQIANG CHEM IND TECH RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This method reaction step is complicated, needs to use a large amount of carbon tetrachloride solvents, and product content is low, and yield is low, and production cost is high, and environmental pollution is big

Method used

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  • Production method for 2-nitrobenzyl bromide
  • Production method for 2-nitrobenzyl bromide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] In a 1000ml three-necked flask, add 250g of water, 100g of o-nitrotoluene, PEG6002g, 110g of HBr with a mass concentration of 48%, and 10g of azobisisobutyronitrile, and dropwise add hydrogen peroxide with a mass concentration of 30% at 50-55°C 80g, after dripping for about 1 hour, keep it warm at this temperature for 6 hours until the redness fades away, remove the upper water layer, wash the lower layer with 5% sodium sulfite, then wash with water, add 100ml petroleum ether, stir and heat up Dissolved; after dissolving, the petroleum ether solution was lowered to room temperature, and the solution was layered. Petroleum ether was rinsed to obtain o-white nitrobenzyl bromide solid with a content of 80.7% and a yield of 80.2%. refer to figure 1 , the mobile phase is 80:20=methanol:water, the wavelength is 254nm, and the flow rate is 0.81 / h. The peak with a retention time of 8.4 min is o-nitrobenzyl bromide; the peak with a retention time of 9.9 min is o-nitrobenzyl br...

Embodiment 2

[0023] In a 1000ml three-necked flask, add 250g of water, 100g of o-nitrotoluene, 2g of PEG6002g, 110g of HBr48%, 10g of azobisisobutyronitrile, and dropwise add 80g of 30% hydrogen peroxide at 78-82°C (the above are all in mass ratio) , After about 2 hours of dripping, keep warm at this temperature for 2 hours until the red color fades away, then remove the upper water layer, wash the lower layer with 5% sodium sulfite, and then wash with water, add 100m1 petroleum ether, stir and heat up Dissolved; after dissolving, the petroleum ether solution was lowered to room temperature, and the solution was layered. Petroleum ether was rinsed to obtain o-white nitrobenzyl bromide solid with a content of 78.5% and a yield of 79.4%.

Embodiment 3

[0025] In a 1000ml three-neck flask, add 250g of water, 100g of o-nitrotoluene, 2g of PEG6002g, 110g of HBr48%, 4g of azobisisobutyronitrile, and dropwise add 50g of 30% hydrogen peroxide at 78-82°C, then cool down to 55°C, Add 6g of azobisisobutyronitrile, continue to add 30g of 30% hydrogen peroxide dropwise at this temperature (the above are all mass ratios), after the addition is completed, keep the reaction at this temperature for 6 hours until the red color fades away, and then remove the upper layer The water layer, the lower material layer was washed with 5% sodium sulfite, and then washed with water, and 100ml of petroleum ether was added, stirred and heated to dissolve; after dissolution, the petroleum ether solution was lowered to room temperature, and the solution was layered. The lower layer was the raw material of o-nitrotoluene, Put the upper layer of petroleum ether solution directly into the refrigerator to refrigerate and let it stand, white crystals precipita...

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Abstract

The invention discloses a production method for 2-nitrobenzyl bromide. The method comprises the following steps: raw materials comprising 100kg of ortho-nitrotoluene, 110kg of hydrogen bromide with a mass concentration of 48%, 10kg of a catalyst azodiisobutyronitrile and 2kg of a phase transfer agent polyvinyl alcohol PEG600 are added into 250kg of water, the above mixture is stirred and heated up, 100kg of hydrogen peroxide with a mass concentration of 30% are added dropwisely and slowly at the temperature of 50-82 DEG C. After the addition, the mixture is subjected to a thermal insulation reaction for hours until the red color fades away. The upper layer water layer is separated, and the lower layer material layer is washed to be neutral with 5% of sodium sulfite, and then washed with water. With petroleum ether as a solvent, the synthetics are subjected to recrystallization and purification, and white crystal 2-nitrobenzyl bromide is obtained. Each material can be amplified according to the given weight ratios. No organic solvents are employed, the post-treatment is simple, and the cost is low. The reaction yield is above 79.4%, and is far higher than the yield 72% of traditional technology production.

Description

technical field [0001] The invention belongs to the field of chemical materials, and in particular relates to a production method of o-nitrobenzyl bromide. Background technique [0002] O-nitrobenzyl bromide is an important intermediate for the synthesis of new broad-spectrum fungicide pyraclostrobin (also known as pyraclostrobin, English common name: Pyraclostrobin), its molecular formula C 7 h 6 BrNO 2 , Melting point: 44-46 ° C, alias 2-nitrobenzyl bromide, CAS number: 3958-60-9, high-purity product (content ≥ 95%) is light yellow or white crystal. [0003] [0004] Pyraclostrobin is a broad-spectrum fungicide of methyl methoxyacrylate with a pyrazole structure launched by BASF in 2002. It can prevent and cure plant diseases caused by all types of true pathogens, such as Ascomycetes Leaf blight, rust, powdery mildew, downy mildew, blight, anthracnose, brown spot, blight, etc. caused by basidiomycetes, deuteromycetes and oomycetes. It has good control effect on cucu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/11C07C201/12
Inventor 刘方廖大章陈允珊单晓军
Owner SHANDONG XINGQIANG CHEM IND TECH RES INST CO LTD
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