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Method for synthesizing phenylhydrazine

A technology of phenylhydrazine and hydrazine hydrate, which is applied in the directions of hydrazine preparation and chemical recovery, can solve the problems of many reaction steps, easy decomposition and high cost, and achieves the effects of less by-products and wastes, mild reaction conditions and fewer reaction steps.

Inactive Publication Date: 2018-05-04
重庆丽澄环保科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Synthesis of phenylhydrazine by diazotization reaction, the intermediate diazonium salt is unstable and easy to decompose, it needs to be carried out under low temperature conditions, the reaction steps are many, the production process is complicated, the energy consumption is high, and the total yield is only about 80%. There are many products and wastes, and a large amount of organic salty wastewater will be produced. Environmental protection treatment is difficult and costly, and it is easy to pollute the environment.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Put 188g of phenol, 166.7g of hydrazine hydrate with a content of 90% and 37.6g of sodium tripolyphosphate into a four-neck flask equipped with stirring, a thermometer and a rectification column, start stirring, heat up to 110°C to 120°C, and The temperature at the top of the distillation column is 98°C to 100°C to extract water vapor. After 6 to 8 hours of reaction, take samples for analysis. When the content of phenol in the reaction solution is lower than 0.3%, the reaction is terminated, and then the excess hydrazine hydrate is recovered by distillation under reduced pressure, and the hydrazine hydrate is recovered. After completion, the sodium tripolyphosphate was separated with a centrifugal filter device, and the remaining liquid was washed with an appropriate amount of sodium carbonate solution and pure water to obtain 199.3 g of phenylhydrazine.

Embodiment 2

[0014] Put 188g of phenol, 184.2g of hydrazine hydrate with a content of 95% and 56.4g of sodium tripolyphosphate into a four-neck flask equipped with stirring, a thermometer and a rectification column, start stirring, and heat up to 110°C to 120°C. The temperature at the top of the distillation column is 98°C to 100°C to extract water vapor. After 6 to 8 hours of reaction, take samples for analysis. When the content of phenol in the reaction solution is lower than 0.3%, the reaction is terminated, and then the excess hydrazine hydrate is recovered by distillation under reduced pressure, and the hydrazine hydrate is recovered. After completion, the sodium tripolyphosphate was separated with a centrifugal filter device, and the remaining liquid was washed with an appropriate amount of sodium carbonate solution and pure water to obtain 206.9 g of phenylhydrazine.

Embodiment 3

[0016] Put 188g of phenol, 202g of hydrazine hydrate with a content of 99% and 18.8g of sodium tripolyphosphate into a four-necked flask equipped with a stirring, thermometer and rectification column, start stirring, heat up to 110°C to 120°C, and in the rectification The temperature at the top of the column is 98℃~100℃ to extract water vapor, take samples and analyze after reacting for 6~8 hours, stop the reaction when the content of phenol in the reaction solution is lower than 0.3%, and then recover the excess hydrazine hydrate by distillation under reduced pressure, and the recovery of hydrazine hydrate is completed Finally, the sodium tripolyphosphate was separated with a centrifugal filter device, and the remaining liquid was washed with an appropriate amount of sodium carbonate solution and pure water to obtain 202.7 g of phenylhydrazine.

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PUM

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Abstract

The invention relates to a method for synthesizing phenylhydrazine. The method comprises the following step: performing reaction on phenol and hydrazine hydrate which serve as raw materials by using sodium tripolyphosphate serving as a catalyst at certain temperature to synthesize the phenylhydrazine. In a reaction system, the amount of the hydrazine hydrate keeps excessive, so that the phenol canbe reacted completely; in a reaction process, water generated by the reaction is continuously separated and removed; after the reaction is ended, reduced pressure distillation is performed to recyclethe hydrazine hydrate; after remaining liquid is washed with a sodium carbonate solution and pure water through a separation catalyst, a phenylhydrazine finished product is obtained. Compared with aconventional diazo-reaction process for synthesizing the phenylhydrazine, the method is mild in reaction condition and easy to operate; the number of reaction steps is small, and the number of byproducts and wastes is small; the energy consumption is low, and the yield is 90 percent or above; the catalyst can be recycled, so that the production cost is low; the method is an energy-saving and environmentally-friendly novel process.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for synthesizing phenylhydrazine. Background technique [0002] Phenylhydrazine is a white monoclinic prism crystal or oily liquid, slightly soluble in water, with a melting point of 19.5°C and a boiling point of 243.5°C. It has an aromatic smell and gradually oxidizes to yellow in air. Phenylhydrazine is used in the production of pesticides to synthesize the intermediate 1-phenylsemicarbazide of the organophosphorus insecticide triazophos and the intermediate 1-phenyl-3,6-dihydroxypyridazine of pyridazine, which is also bactericidal In addition, as an organic synthesis raw material, phenylhydrazine is also used as an intermediate in dyes, pharmaceuticals and other industries, and is also used as an analytical reagent. It can react with the aldehyde and ketone groups of sugars to form stable glycosides, and use the crystal form and melting point o...

Claims

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Application Information

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IPC IPC(8): C07C243/22C07C241/02
CPCY02P20/584C07C241/02C07C243/22
Inventor 不公告发明人
Owner 重庆丽澄环保科技有限公司
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