Preparation method of o-nitrobenzyl bromide

A technology of o-nitrobenzyl bromide and o-nitrotoluene, which is applied in the field of preparation of o-nitrobenzyl bromide, can solve the problems of low yield, high cost, and expensive raw materials, and achieve high reaction selectivity and low cost. Inexpensive and readily available raw materials

Inactive Publication Date: 2019-02-22
HUNAN HAILI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, these methods have low yields, expensive raw materials, and relatively high costs.

Method used

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  • Preparation method of o-nitrobenzyl bromide
  • Preparation method of o-nitrobenzyl bromide
  • Preparation method of o-nitrobenzyl bromide

Examples

Experimental program
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Effect test

Embodiment 1

[0029] A preparation method of o-nitrobenzyl bromide, using o-nitrotoluene as a raw material, using NaClO / HBr as a bromination agent, and using azobisisobutyronitrile as an initiator to prepare by bromination reaction Ortho-nitrobenzyl bromide, comprising the following steps:

[0030] (1) Prepare the first mixed solution and the second mixed solution:

[0031] 206g dichloroethane is divided into two parts, respectively the first solvent 136g, the second solvent 70g; 2.5g azobisisobutyronitrile (AIBN) is divided into two parts, respectively the first initiator 0.5g, the second initiator Dose 2.0g.

[0032] With 41.2g (0.30mol) o-nitrotoluene, 136g dichloroethane (the first solvent), 54.6g hydrobromic acid solution (the mass concentration of hydrobromic acid in this solution is 40%, promptly contains 0.27mol in this solution hydrobromic acid) and 0.5g azobisisobutyronitrile (the first initiator) were mixed uniformly to obtain the first mixed solution.

[0033] Mix 2.0 g of az...

Embodiment 2

[0037] A preparation method of o-nitrobenzyl bromide, using o-nitrotoluene as a raw material, using NaClO / HBr as a bromination agent, and using azobisisobutyronitrile as an initiator to prepare by bromination reaction Ortho-nitrobenzyl bromide, comprising the following steps:

[0038] (1) Prepare the first mixed solution and the second mixed solution:

[0039] 247g dichloroethane is divided into two parts, respectively the first solvent 177g, the second solvent 70g; 3.5g azobisisobutyronitrile (AIBN) is divided into two parts, respectively the first initiator 0.5g, the second initiator Dose 3.0g.

[0040] With 41.2g (0.30mol) o-nitrotoluene, 177g dichloroethane (the first solvent), 50.6g hydrobromic acid solution (the mass concentration of hydrobromic acid in this solution is 48%, promptly contains 0.30mol hydrobromic acid) and 0.5g azobisisobutyronitrile (the first initiator) were mixed uniformly to obtain the first mixed solution.

[0041] 3.0 g of azobisisobutyronitrile ...

Embodiment 3

[0045] A preparation method of o-nitrobenzyl bromide, using o-nitrotoluene as a raw material, using NaClO / HBr as a bromination agent, and using azobisisobutyronitrile as an initiator to prepare by bromination reaction Ortho-nitrobenzyl bromide, comprising the following steps:

[0046] (1) Prepare the first mixed solution and the second mixed solution:

[0047] 230g carbon tetrachloride is divided into two parts, respectively the first solvent 160g, the second solvent 70g; 2.5g azobisisobutyronitrile (AIBN) is divided into two parts, respectively the first initiator 0.5g, the second initiator Dose 2.0g.

[0048] With 41.2g (0.30mol) o-nitrotoluene, 160g carbon tetrachloride (the first solvent), 66.7g hydrobromic acid solution (the mass concentration of hydrobromic acid in this solution is 40%, promptly contains 0.33mol in this solution hydrobromic acid) and 0.5g azobisisobutyronitrile (the first initiator) were mixed uniformly to obtain the first mixed solution.

[0049] 2.0...

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Abstract

The invention discloses a preparation method of o-nitrobenzyl bromide. The preparation method comprises the steps that ortho-nitrotoluene is taken as a raw material, NaClO / HBr is taken as a bromatingagent, and the o-nitrobenzyl bromide is prepared through a bromating reaction under the initiation effect of azodiisobutyronitrile serving as an initiator. According to the preparation method, the NaClO / HBr is taken as the bromating agent to prepare the o-nitrobenzyl bromide, raw materials are easy obtain and low in cost, the technology is easy, convenient and easy to operate, the reaction condition is mild, reaction selectivity is high, the reaction yield is greater than 72% (by ortho-nitrotoluene), the content of the o-nitrobenzyl bromide in a purified solid product is greater than 97%, andthe preparation method is suitable for being popularized in an industrialization mode.

Description

technical field [0001] The invention relates to a preparation method of o-nitrobenzyl bromide. Background technique [0002] O-nitrobenzyl bromide is an important intermediate of the pesticide pyraclostrobin, and its chemical formula is as follows: [0003] [0004] The preparation method of o-nitrobenzyl bromide mainly takes o-nitrotoluene as raw material, with Br 2 、H 2 o 2 / HBr, KBrO 3 / HBr, NBS, etc. are used as bromination agents to prepare o-nitrobenzyl bromide under light or free radical initiators such as azobisisobutyronitrile. However, these methods have low yields, expensive raw materials, and relatively high costs. For example: using o-nitrotoluene as the starting material, o-nitrobenzyl bromide is obtained through bromination reaction, with a yield of 58% to 62% (calculated in o-nitrotoluene), and its synthesis method is as follows: [0005] [0006] Therefore, it is of great significance to obtain a preparation method of o-nitrobenzyl bromide with e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/12C07C205/11
CPCC07C201/12C07C205/11
Inventor 熊莉莉杜升华兰世林孔晓红刘源王艳丽程超
Owner HUNAN HAILI CHEM IND
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