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Synthetic method of phenylhydrazine hydrochloride

A technology of phenylhydrazine hydrochloride and synthesis method, which is applied in the field of organic synthesis, can solve problems such as product yield reduction, serious environmental pollution, and nitrogen salt instability, and achieve the effects of easy reaction temperature, simple operation, and mild reaction conditions

Active Publication Date: 2015-05-27
台州新农科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Preparation of phenylhydrazine hydrochloride by diazotization reaction. The intermediate diazonium salt is unstable and easy to decompose. It needs to be carried out under low temperature conditions, and the product yield is reduced; a large amount of waste water is generated during the reaction process, which seriously pollutes the environment.

Method used

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  • Synthetic method of phenylhydrazine hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The synthetic method of phenylhydrazine hydrochloride:

[0019] In a 1000mL four-necked flask equipped with a mechanical stirrer, a dropping funnel, a reflux condenser and a thermometer, dissolve 93g (1mol) of aniline in 500mL of 2M dilute hydrochloric acid, then add 64g (1.07mol) of urea, stir to dissolve, and heat to reflux 2h, hot filtration, cooling, the filtrate precipitated crystals. The crystals were washed with a small amount of cold water, and the filtrate and washings were refluxed again. Repeat the operation more than three times to obtain crude N-phenylurea. Crude N-phenylurea was recrystallized and dried to obtain 117.6 g of N-phenylurea, yield 86.4%, mp: 145-147°C.

[0020] In a 500mL four-necked flask equipped with a mechanical stirrer, a dropping funnel, a reflux condenser and a thermometer, dissolve 58.5g (0.43mol) of N-phenylurea in ethanol, control the temperature at 15°C, and add dropwise to the solution The ethanol solution containing 32g (0.45mo...

Embodiment 2

[0024] The synthetic method of phenylhydrazine hydrochloride:

[0025] The preparation of N-phenylurea is the same as in Example 1.

[0026] In a 500mL four-neck flask equipped with a mechanical stirrer, a dropping funnel, a reflux condenser and a thermometer, dissolve 58.5g (0.43mol) of phenylurea in methanol, control the temperature at 15°C, and dropwise add 32g of (0.45mol) methanol solution of chlorine gas, after the dropwise addition, continue to react for half an hour. Under the condition of ice-water bath, 86g (2.15mol) NaOH aqueous solution was slowly added dropwise, and the reaction was continued for half an hour after the dropwise addition was completed. Filter, heat and distill off methanol and part of the water, and extract the remaining mixture with toluene. First distill the toluene from the extract, and then distill the fraction at 120-125°C / 10mmHg under reduced pressure to obtain phenylhydrazine. The obtained phenylhydrazine was added dropwise to hydrochlori...

Embodiment 3

[0030] The synthetic method of phenylhydrazine hydrochloride:

[0031] The preparation of N-phenylurea is the same as in Example 1.

[0032] In a 500mL four-necked flask equipped with a mechanical stirrer, a dropping funnel, a reflux condenser and a thermometer, dissolve 58.5g (0.43mol) of phenylurea in ethanol, control the temperature at 15°C, and dropwise add 62g of (0.86mol) ethanol solution of chlorine gas, after the dropwise addition, continue to react for half an hour. Under the condition of ice-water bath, 86g (2.15mol) NaOH aqueous solution was slowly added dropwise, and the reaction was continued for half an hour after the dropwise addition was completed. Filter, heat and distill off ethanol and part of the water, and extract the remaining mixture with toluene. First distill off the toluene from the extract, and then distill off the fraction at 120-125°C / 10mmHg under reduced pressure to obtain phenylhydrazine. The obtained phenylhydrazine was added dropwise to hydr...

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Abstract

The invention relates to a synthetic method of phenylhydrazine hydrochloride. The synthetic method comprises the following steps of: dissolving phenylamine into dilute hydrochloric acid, then adding urea, heating and carrying out reflux reaction to prepare N-phenylurea, dissolving N-phenylurea into a solvent, and introducing chlorine for reaction to obtain chloroaminophenylurea; dropping an NaOH water solution under the condition of ice-water bath, extracting and distilling to obtain phenylhydrazine, dropping phenylhydrazine to a hydrochloric acid solution, and reducing temperature for crystallization to obtain phenylhydrazine hydrochloride. The synthetic method disclosed by the invention has the advantages of moderation in reaction condition, easiness for operation, high yield and recycling of the used solvent and an extracting agent and is favorable to industrialized production.

Description

technical field [0001] The invention relates to a synthesis method of phenylhydrazine hydrochloride and belongs to the technical field of organic synthesis. Background technique [0002] As a raw material for organic synthesis, phenylhydrazine hydrochloride can be used as an intermediate in dyes, medicine and other industries, and also as an analytical reagent. In the production of pesticides, it is used to synthesize the intermediate 1-phenyl-3,6-dihydroxypyridazine of the organophosphorus insecticide pyridazine, and the intermediate of the fungicides oxaflucone and midafosone, etc. Phenylhydrazine hydrochloride can also react with the aldehyde and ketone groups of sugar to form stable glycosides. The crystal form and melting point of glycosides can be used to identify different reducing sugars. [0003] Phenylhydrazine hydrochloride is generally diazotized by aniline and sodium nitrite in acidic medium to generate diazonium salt, and then reduced with a reducing agent to ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C243/22C07C241/02
Inventor 张志德满成娜陈玉琴郑学梅
Owner 台州新农科技有限公司
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