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Method of refining aromatic halogenated benzene compound

A technology for benzene compound and aromatic halogenation, which is applied in the field of refining aromatic halogenated benzene compounds, can solve the problems of harsh operating conditions and high energy consumption, and achieves the effects of easy industrial operation, high refining yield and widening application scope.

Inactive Publication Date: 2007-10-24
PENGLAI WEIXUN RES INST OF FINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0002] Aromatic halogenated benzene compounds are often used as intermediates of fine chemicals such as dyes, medicines, and pesticides. This product is usually prepared by direct or indirect halogenation of appropriate aromatic compounds as raw materials. Aromatic compounds are usually prone to isomerization during halogenation Body or polyhalogenated products, the refining method reported in the literature usually adopts the method of high vacuum distillation, and the method of high vacuum distillation has high energy consumption and harsh operating conditions. Therefore, looking for a refining method with low cost and easy industrial operation, High-purity aromatic halogenated benzene compounds can be obtained more conveniently, meeting the requirements for the synthesis of pharmaceuticals and other fine chemicals

Method used

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  • Method of refining aromatic halogenated benzene compound
  • Method of refining aromatic halogenated benzene compound
  • Method of refining aromatic halogenated benzene compound

Examples

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Embodiment 1

[0015] Embodiment 1, a method for refining aromatic halogenated benzene compounds, is that the refined aromatic halogenated benzene compounds have the following general structural formula:

[0016]

[0017] Among them: R1, R2, R3 can be the same or different, each can represent H, NO 2 , Cl, C 1-4 Alkyl or alkoxy groups, X represents a halogen atom, such as F, Cl, Br, I, etc., wherein preferentially represent Cl and Br; present embodiment is that 60 grams of 93% 2-methyl-4-ethoxy Bromobenzene, add 120mL of methanol into the reaction flask, cool down to 0°C with constant stirring, keep warm for 3 hours, filter, drain, wash with 20mL of methanol, drain, add 100mL of 60°C hot water to melt, and let stand , The water layer was separated to obtain 54.0 g of 2-methyl-4-ethoxybromobenzene with a content of 99.15% and a yield of 96.17%.

Embodiment 2

[0018] Embodiment 2, a method for refining aromatic halogenated benzene compounds, the general structural formula of the refined aromatic halogenated benzene compounds is the same as that of Example 1, and 70 grams of 90% 2,5-dimethyl-4-methoxy Add bromobenzene, 60mL of toluene and 60mL of isopropanol into the reaction flask, cool down to -8°C with constant stirring, keep warm for 4 hours, filter, drain, wash with 10mL solvent, drain, evaporate in a distillation flask The remaining solvent was removed to obtain 56.5 g of 2,5-dimethyl-4-methoxybromobenzene with a content of 99.20% and a yield of 89.28%.

Embodiment 3

[0019] Example 3, a method for refining aromatic halogenated benzene compounds, the refined aromatic halogenated benzene compound has the same structural formula as in Example 1, which is to mix 70 grams of 92% 2-nitro-4-ethoxychlorobenzene Add 100mL of methanol and 20mL of n-hexane into the reaction flask, lower the temperature to -5°C with constant stirring, keep warm for 6 hours, filter, drain, wash with 10mL solvent, drain, and distill off the residual solvent in the distillation flask , to obtain 58.0 g of 2-nitro-4-ethoxychlorobenzene, with a content of 99.08%, and a yield of 89.23%.

[0020] Preface

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Abstract

The invention discloses a refining method of aromatic halogen-benzene compound, which comprises the following steps: blending the aromatic halogen-benzene compound and solvent completely; cooling; insulating under -20-20 deg. c for 0-8h; crystallizing; filtering; washing; separating the crystal mother liquid; adding hot water into crystallized solid to melt; washing completely or distilling directly to remove residual solvent; obtaining high-purity product. The invention is easy to do industrial operation, which satisfies the need of drug and fine chemicals.

Description

1. Technical field [0001] The invention belongs to the technical field of fine chemicals, in particular to a method for refining aromatic halogenated benzene compounds 2. Technical Background [0002] Aromatic halogenated benzene compounds are often used as intermediates of fine chemicals such as dyes, medicines, and pesticides. This product is usually prepared by direct or indirect halogenation of appropriate aromatic compounds as raw materials. Aromatic compounds are usually prone to isomerization during halogenation Body or polyhalogenated products, the refining method reported in the literature usually adopts the method of high vacuum distillation, and the method of high vacuum distillation has high energy consumption and harsh operating conditions. Therefore, looking for a refining method with low cost and easy industrial operation, High-purity aromatic halogenated benzene compounds can be obtained more conveniently, meeting the requirements for the synthesis of medicin...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/38C07C25/00C07C41/34C07C43/20C07C201/06C07C205/00
Inventor 姚建文王万杰吕孝虎林素美
Owner PENGLAI WEIXUN RES INST OF FINE CHEM