Synthesis method for dimethyl azodicarboxylate and intermediate thereof

A technology of dimethyl azodicarboxylate and dimethyl hydrogen azodicarboxylate is applied in the preparation of hydrazide, organic chemistry, etc., can solve problems such as environmental pollution, and achieves good economy, high yield and simple operation Effect

Active Publication Date: 2013-01-30
SHANDONG NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method saves the cost to a certain extent, and the intensity of the reaction is slowed down, but it is easy to produce a large amount of nitrogen-containing compounds, which has great pollution to the environment.

Method used

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  • Synthesis method for dimethyl azodicarboxylate and intermediate thereof
  • Synthesis method for dimethyl azodicarboxylate and intermediate thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0042] In a 500ml three-necked flask equipped with mechanical stirring, 250ml of dimethyl carbonate was added, and 125g of hydrazine hydrate with a mass percentage of 80% was added. The mixture was heated to reflux in an oil bath for 5 hours, and the excess dimethyl carbonate was evaporated. After the remaining mixed solution was spin-dried under reduced pressure, the crude methyl carbazate was obtained. Recrystallization with acetone gave 171 g (95.0%) of white transparent crystals, mp=69-72°C.

[0043] II, the preparation of dimethyl hydrogen azodicarboxylate

Embodiment 2

[0045] In a 250ml three-necked flask equipped with mechanical stirring, add 120ml of anhydrous methanol, add 6.9g of sodium metal under nitrogen protection, after the sodium metal is completely dissolved, add 27g of methyl carbazate, and after 0.5h, the solution turns orange red . Slowly add 30 g of dimethyl carbonate dropwise, and after the dropwise addition, react at room temperature for 6 hours to obtain a light yellow turbid liquid, and recover methanol and dimethyl carbonate by atmospheric distillation. Adjust pH≈6.0 with 10% hydrochloric acid solution, white crystals are precipitated, washed with cold water to obtain a crude product of dimethyl hydrogen azodicarboxylate, and the above crude product is successively recrystallized with acetone and petroleum ether to obtain a white solid hydrogen azo Dimethyl diformate 5.4g (12.2%) mp=131-133℃.

[0046] 1 HNMR (CDCl 3 ,300MHz)δ:9.06(2H,s,NH);3.58(6H,s,CH 3 ).

Embodiment 3

[0048]In a 250ml three-necked flask equipped with mechanical stirring, add 120ml of anhydrous methanol, add 6.9g of sodium metal under nitrogen protection, after the sodium metal is completely dissolved, add 27g of methyl carbazate, and after 0.5h, the solution turns orange red . Slowly add 30 g of dimethyl carbonate dropwise, and react at 65° C. for 6 h after the dropwise addition to obtain a light yellow turbid liquid. Methanol and dimethyl carbonate are recovered by atmospheric distillation. Adjust pH≈6.0 with 10% hydrochloric acid solution, white crystals are precipitated, washed with cold water to obtain a crude product of dimethyl hydrogen azodicarboxylate, and the above crude product is successively recrystallized with acetone and petroleum ether to obtain a white solid hydrogen azo Dimethyl diformate 36.7g (82.7%) mp=131-133℃.

[0049] 1 HNMR (CDCl 3 ,300MHz)δ:9.06(2H,s,NH);3.58(6H,s,CH 3 ).

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Abstract

The invention discloses a synthesis method for dimethyl azodicarboxylate; and the synthesis method comprises the following steps of: (1) heating dimethyl carbonate and methyl hydrazinocarboxylate for 1-6 h under an effect of sodium methoxide; adjusting pH value of a solution to 3-8; separating out white crystals; and recrystallizing the white crystals so as to obtain hydrogenated dimethyl azodicarboxylate; (2) adding the hydrogenated dimethyl azodicarboxylate at (-15)-(45) DEG C; with bromine, hydrobromic acid or sodium bromide and potassium bromide as a catalyst, dripping excessive hydrogen peroxide to an acidic solution to react for 1-10 h; extracting a reaction liquid; and distilling the reaction liquid to remove an organic solvent, so as to obtain flavescent dimethyl azodicarboxylate. The invention further provides the intermediate hydrogenated dimethyl azodicarboxylate and a synthesis method therefore. As the dimethyl carbonate is used as a raw material, the synthesis method for the dimethyl azodicarboxylate, disclosed by the invention, has the advantages of cleanness, environment friendliness, no pollution, recyclable raw materials, better economic efficiency, simplicity in operation, wide reaction temperature range, stability in reaction, low energy consumption and high yield and is beneficial for industrial production.

Description

technical field [0001] The invention relates to a method for synthesizing dimethyl azodicarboxylate and an intermediate thereof. Background technique [0002] Azodicarboxylates are a class of compounds with both azo and carboxyl functional groups. Due to their unique electronic and structural properties, azodicarboxylates have been widely used as a multifunctional reagent in organic synthesis. Especially in the Mitsunobu reaction, the amination of carbonyl compounds, the amination of unsaturated hydrocarbons and the synthesis of heterocyclic compounds, it has a very important role. In addition, azodicarboxylate can also be used as an oxidant for the removal of alcohols and amines. Hydroxidation reaction. Dimethyl azodicarboxylate (DMAD) is the main member of this class of reagents and is widely used in the fields of pharmaceutical intermediates, foaming polymers and free radical initiators. [0003] Dimethyl azodicarboxylate can be synthesized by the method proposed by Di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C245/04C07C243/28C07C241/04
Inventor 张志德吕硕陈玉琴张兴红
Owner SHANDONG NORMAL UNIV
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