Method for preparing diphenyl hydrazine

A technology of diphenylhydrazine and nitrobenzene, which is applied in the preparation of hydrazine, organic chemistry, etc., can solve the problems of no industrial advantages, high price, and high cost, and achieve the effects of short reaction time, low cost, and high conversion rate

Inactive Publication Date: 2010-09-22
周成云
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  • Application Information

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Problems solved by technology

Electrolysis and catalytic hydrogenation are green synthesis processes. Due to low yield, high cost, and difficult to solve electrochemical engineering problems, electrolytic reduction has not been reported on industrialization; in comparison, aromatic nitrogen-containing compounds are used as raw materials There are many studies on the synthesis of diphenylhydrazine by catalytic hydrogenation. For example, using nitrobenzene as a raw material, in a strong alkaline (NaOH or KOH) alcohol solution at 20 to 90 ° C, in the presence of Pd / C or Pt / C catalyst. High-pressure or low-pressure catalytic hydrogenation is the most convenient way, but because Pd or Pt is expensive, and the price of hydroazobenzene is not high, so this method has no industrial advantages

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0018] Preparation of Raney Nickel:

[0019] Add 20g of nickel aluminum alloy, 1g of copper chloride, and 2g of cobalt nitrate in batches to 80g of sodium hydroxide solution. After the addition, control the temperature at 80°C until almost no gas escapes. After cooling, wash with sodium hydroxide solution, then wash with distilled water to near neutrality, wash with methanol for 3 times, and then soak in appropriate amount of methanol to prevent Raney nickel from contacting with air.

[0020] Preparation of diphenylhydrazine:

[0021] Add 50g of nitrobenzene, 150g of anhydrous methanol, 60g of sodium hydroxide and 5g of Raney nickel into the stainless steel reaction kettle, feed 0.05MPa of ammonia gas, keep the pressure of hydrogen at 0.8MPa, stir and react at room temperature for 5 hours, then unload Press, pour out the reaction solution, stir and soak the catalyst at the bottom of the kettle once with 20g of methanol (the catalyst can be used mechanically), combine the Rane...

Embodiment 2

[0023] Preparation of Raney Nickel:

[0024] Add 20g of nickel aluminum alloy, 1g of copper chloride, and 2g of cobalt nitrate in batches to 80g of sodium hydroxide solution. After the addition, control the temperature at 80°C until almost no gas escapes. After cooling, wash with sodium hydroxide solution, then wash with distilled water to near neutrality, wash with methanol for 3 times, and then soak in appropriate amount of methanol to prevent Raney nickel from contacting with air.

[0025] Preparation of diphenylhydrazine:

[0026] Add 50g of nitrobenzene, 200g of anhydrous methanol, 80g of sodium hydroxide and 7g of Raney nickel into the stainless steel reaction kettle, feed 0.10MPa of ammonia gas, keep the hydrogen pressure stable at 0.6MPa, stir and react at room temperature for 12 hours, then unload Press, pour out the reaction solution, stir and soak the catalyst at the bottom of the kettle once with 30g of methanol (the catalyst can be used mechanically), combine the...

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Abstract

The invention relates to a method for preparing diphenyl hydrazine. The method comprises the steps of: adding nitrobenzene, absolute methanol, sodium hydroxide and a certain mass of Raney nickel in a stainless steel reactor; introducing 0.05-0.10 MPa of ammonia gas; maintaining the pressure of hydrogen at 0.2-0.8 MPa; releasing the pressure after reaction for a period by stirring at a room temperature; pouring a reaction liquid out; stirring and soaking the catalyst at the bottom of the reactor with methanol for one time; blending the catalyst soaking liquid, i.e., methanol, with the reaction liquid, and then pouring into a separating funnel; adding a proper amount of diluted HCl for neutralization; separating the water layer at the lower part out after being neutral; extracting with methanol; pouring the blended liquid of a grease layer and an extraction liquid into a flask; and after obtaining a part of solvent methanol by decompression and distilling, separating out yellowy plate crystals, i.e., diphenyl hydrazine, by cooling and crystallization. The method has the characteristics of high yield, easy operation and the like.

Description

technical field [0001] The invention relates to a preparation method of diphenylhydrazine. Background technique [0002] Hydroazobenzene (i.e. diphenylhydrazine) is an important pharmaceutical intermediate and chemical raw material. Its traditional synthesis methods mainly include hydrazine hydrate method, formaldehyde method, formic acid method, zinc powder method, iron powder method, sodium oxysulfide method, etc. my country's industry mainly adopts zinc powder or glucose and ferrosilicon powder reduction method of nitrobenzene under alkaline conditions for production, but these methods are serious wastes. Electrolysis and catalytic hydrogenation are green synthesis processes. Due to low yield, high cost, and difficult to solve electrochemical engineering problems, electrolytic reduction has not been reported on industrialization; in comparison, aromatic nitrogen-containing compounds are used as raw materials There are many studies on the synthesis of diphenylhydrazine b...

Claims

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Application Information

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IPC IPC(8): C07C243/22C07C241/02
Inventor 周成云
Owner 周成云
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