Preparation method of 2,3-dichlor-1,4-naphthaquinones

A technology of naphthoquinone and naphthylamine, applied in 2 fields, to achieve the effect of heavy recovery workload, large solvent loss and low cost

Active Publication Date: 2007-11-07
常州华达纳米材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The common point of these six methods is that chlorine gas is introduced into the organic solvent for chlorination, and there are problems of chlorine gas tail gas treatment and organic solvent recovery.

Method used

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  • Preparation method of 2,3-dichlor-1,4-naphthaquinones
  • Preparation method of 2,3-dichlor-1,4-naphthaquinones

Examples

Experimental program
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Embodiment 1

[0034] (1) Sodium 1,4-acid dissolved

[0035] Add 150Kg of sodium 1,4-acid into the reaction pot, add 500Kg of water, heat up to stir and dissolve. Add hydrochloric acid dropwise to control the pH value from 2 to 5, and stir for 10 minutes.

[0036] (2) Chlorine

[0037] Add 5Kg of iron powder and stir for 15 minutes. Feed chlorine gas, control the temperature at 30-90° C., react for 20 hours, until the reaction is complete (the analysis shows that no raw material 1,4-acid sodium exists), and then stop the chlorine flow. Cool to 35°C and filter to dryness.

[0038] (3) Recrystallization

[0039] To obtain 150Kg of crude product (content: 95%), add 750Kg of ethanol and heat up to reflux. Cool to 30°C. Suction filter to dryness. Control the temperature of the oven at 50-70° C., bake for 5 hours until dry, and obtain 110 Kg of the product (2,3-dichloro-1,4-naphthoquinone) with a content of more than 98.5%.

Embodiment 2

[0041] Change hydrochloric acid into sulfuric acid in embodiment 1, obtain product (2,3-dichloro-1,4-naphthoquinone) 108Kg, content more than 98.5%

Embodiment 3

[0043] Change hydrochloric acid into phosphoric acid in embodiment 1, obtain product (2,3-dichloro-1,4-naphthoquinone) 100Kg, content more than 98.5%

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Abstract

The invention relates to the preparation method of 2,3-dichlor-1,4-naphthaquinones, which comprises, (1) charging sodium-1-naphthylamine-4-sulfonate into water, adjusting pH to 2-5 by charging acid, (2) charging 1-10% of iron powder, zinc powder, ferric salt, ferrous salt or zinc salt, (3) letting in chlorine, (4) cooling down the reaction product at normal temperature, filtering to obtain 2,3-dichloro-1,4-naphthaquinone crude product, finally recrystallizing with organic solvents to obtain product with the content higher than 98.5%.

Description

1. Technical field [0001] The invention relates to a preparation method of naphthoquinone, in particular to a preparation method of 2,3-dichloro-1,4-naphthoquinone. 2. Background technology [0002] 2,3-dichloro-1,4-naphthoquinone (DCNQ for short) is a catalyst for reducing azobenzene and its related derivatives with formaldehyde to generate hydroazobenzene and its derivatives. It is an important fine chemical, which can be used as herbicide, fungicide for agricultural seeds, antifungal agent for wood and cotton fiber, rubber, etc. [0003] There are few domestic reports about the synthesis of this product. People such as Gao Jianrong of Zhejiang University of Technology used 1,4-naphthoquinone to catalyze the chlorination of this product; people such as Tianjin Dyestuff Industry Research Institute Wang Shaoxing also discussed the synthetic method of this product. These The method can be summarized as follows: [0004] (1) Synthesis of DCNQ with refined naphthalene as raw ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C50/24C07C46/00
Inventor 徐光辉
Owner 常州华达纳米材料科技有限公司
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