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Preparation method of dialkyl azodicarboxylate

A technology of dialkyl azodicarboxylate and diethyl dicarboxylate, which is applied in the field of preparation of dialkyl azodicarboxylate, and can solve problems such as environmental pollution, large dosage, and dangerous by-products

Pending Publication Date: 2021-09-14
浙江瑞博制药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Using propyl chloroformate and hydrazine hydrate as starting raw materials, replacing organic solvent with water as the reaction medium to prepare dipropyl hydrazine dicarboxylate, and then oxidizing it with nitric acid to obtain DPAD. However, direct use of nitric acid as an oxidizing agent has a large amount (greater than 1eq), produces a large amount of dangerous by-products (NOx), and has problems such as environmental pollution.

Method used

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  • Preparation method of dialkyl azodicarboxylate
  • Preparation method of dialkyl azodicarboxylate
  • Preparation method of dialkyl azodicarboxylate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] In a 250ml four-neck flask equipped with mechanical stirring, put 20g of diethyl hydrazinodicarboxylate, 60g of dichloromethane, and 0.35g of nitric acid with a concentration of 65-68%, stir and dissolve, vacuumize, replace with oxygen, and ventilate at 25°C. Oxygen reacted for 48 hours, after the reaction was completed, put 20% sodium bicarbonate aqueous solution into the reaction bottle to adjust the pH to 6-7, separate the water layer, extract the water layer with dichloromethane, combine the dichloromethane layer, add anhydrous magnesium sulfate to dry, filter , Atmospheric pressure distilled dichloromethane, and the residue was distilled under reduced pressure to collect 18.78 g of fractions (yield 95%).

Embodiment 2

[0023] In a 250ml four-neck flask equipped with mechanical stirring, put 20g of diethyl hydrazinodicarboxylate, 60g of dichloromethane, and 5.5g of nitric acid with a concentration of 65-68%, stir and dissolve, vacuumize, replace with oxygen, and ventilate at 25°C. Oxygen reacted for 9 hours, after the reaction was completed, put 20% sodium carbonate aqueous solution into the reaction bottle to adjust the pH to 6-7, separate the water layer, extract the water layer with dichloromethane, combine the dichloromethane layer, add anhydrous magnesium sulfate to dry, filter , Dichloromethane was distilled off under normal pressure, and the residue was distilled under reduced pressure to collect 18.98 g of fractions (yield 96%).

Embodiment 3

[0025] In a 250ml four-neck flask equipped with mechanical stirring, put 20g of diethyl hydrazinodicarboxylate, 80g of ethyl acetate, and 0.21g of nitric acid with a concentration of 98%, stir and dissolve, vacuumize, replace with oxygen, and react with oxygen at 30°C After 35 hours, the reaction was completed. Put 10% sodium hydroxide aqueous solution into the reaction bottle to adjust the pH to 6-7, separate the water layers, extract the water layer with dichloromethane, combine the dichloromethane layers, add anhydrous magnesium sulfate to dry, filter, Dichloromethane was distilled off under normal pressure, and the residue was distilled under reduced pressure to collect fractions of 19.18 g (97% yield).

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Abstract

The invention belongs to the field of pharmaceutical chemicals, and particularly relates to a preparation method of dialkyl azodicarboxylate. The dialkyl azodicarboxylateis prepared from dialkyl hydrazinodicarboxylate through an oxidation reaction, and an oxidant is oxygen. In the prior art, nitric acid is directly used as theoxidant, so that the problems of large dosage (greater than 1eq), generation of a large amount of dangerous byproducts (NOx), environmental pollution and the like exist. The reaction is homogeneous reaction, the reaction is stable, the operation is simple, and the reaction temperature range is wide; and the method is low in energy consumption, low in cost, high in yield, clean, environment-friendly, pollution-free, better in economical efficiency, high in safety coefficient and beneficial to industrial production.

Description

technical field [0001] The invention belongs to the field of medicine and chemical industry, and in particular relates to a preparation method of dialkyl azodicarboxylate. Background technique [0002] Dialkyl azodicarboxylate is a class of compounds with both azo and carboxyl functional groups, the more common ones are dimethyl azodicarboxylate (DMAD), diethyl azodicarboxylate (DEAD), azo Diisopropyl dicarboxylate (DIAD), dibenzyl azodicarboxylate (DBAD). Due to their unique electronic and structural properties, dialkyl azodicarboxylates have been widely used as a multifunctional reagent in organic synthesis, especially in the Mitsunobu reaction, amination of carbonyl compounds, unsaturated hydrocarbon It plays a very important role in the ammoniation and synthesis of heterocyclic compounds. Azodicarboxylates can also be used as oxidants for the dehydrogenation and oxidation reactions of alcohols and amines. In addition, dialkyl azodicarboxylate is an important class of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C281/20
CPCC07C281/20
Inventor 金明辉朱国良吴立猛
Owner 浙江瑞博制药有限公司