Preparation method of adipic acid dihydrazide

A technology of adipic dihydrazide and adipic acid, which is applied in the field of chemistry, can solve the problems of low yield and achieve the effect of improving yield

Inactive Publication Date: 2016-11-16
潍坊芝麻开门化工有限公司
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0005] The present invention proposes a method for preparing adipic acid dihydrazide, which solves the problem in the prior art that adipic acid dihydrazide is synthesized by direct reaction of adipic acid and hydrazine hydrate, and the yield is low

Method used

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  • Preparation method of adipic acid dihydrazide

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preparation example Construction

[0028] Such as figure 1 Shown, this adipate dihydrazide preparation method is characterized in that, comprises the steps:

[0029] S1: Add hexanediol and strong acid salt to methanol, then heat to reflux for esterification to generate dimethyl oxalate;

[0030] S2: adding hydrazine hydrate, then adding the dimethyl oxalate prepared in step S1 to the hydrazine hydrate, and then adding methanol to carry out hydrazine substitution reaction;

[0031] S3: Remove impurities.

[0032] The temperature of the esterification reaction in step S1 is 40° C.-80° C., and the temperature is raised for 1-3 hours during reflux.

[0033] During the hydrazino reaction in step S2, the temperature is controlled at 10°C-50°C.

[0034] Removing impurities in step S3 includes removing methanol by distillation and removing catalyst by desalting.

[0035] In step S2, the dimethyl oxalate prepared in step S1 is added to hydrazine hydrate, the temperature is controlled at 40°C-70°C, and the time is 2-...

Embodiment 1

[0042] S1: Add hexanediol and strong acid salt to methanol, and then heat to reflux for esterification to generate dimethyl oxalate for esterification; S2: Add hydrazine hydrate, then add the hydrazine hydrate in step S1 Add methanol to the obtained dimethyl oxalate for hydrazinolation; S3: remove impurities. The temperature of the esterification reaction in step S1 was 40° C., and the temperature was raised for 1 h during reflux. During the hydrazino reaction in step S2, the temperature was controlled at 10°C. Removing impurities in step S3 includes removing methanol by distillation and removing catalyst by desalting. In step S2, add the dimethyl oxalate prepared in step S1 to hydrazine hydrate, and control the temperature at 40° C. for 2 hours. The molar ratio of adipic acid and methanol in the esterification reaction in step S1 is 1:8. The absorption rate of dimethyl oxalate in step S2 is greater than 75%. The molar ratio of adipic acid to dimethyl adipate produced in s...

Embodiment 2

[0044] S1: Add hexanediol and strong acid salt to methanol, and then heat to reflux for esterification to generate dimethyl oxalate for esterification; S2: Add hydrazine hydrate, then add the hydrazine hydrate in step S1 Add methanol to the obtained dimethyl oxalate for hydrazinolation; S3: remove impurities. The temperature of the esterification reaction in step S1 was 80° C., and the temperature was raised for 3 hours at reflux. During the hydrazino reaction in step S2, the temperature is controlled at 50°C. Removing impurities in step S3 includes removing methanol by distillation and removing catalyst by desalting. In step S2, the dimethyl oxalate prepared in step S1 was added to hydrazine hydrate, and the temperature was controlled at 70° C. for 4 hours. The molar ratio of adipic acid and methanol in the esterification reaction in step S1 is 1:10. The absorption rate of dimethyl oxalate in step S2 is greater than 75%. The molar ratio of adipic acid to dimethyl adipate ...

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Abstract

The invention provides a preparation method of adipic acid dihydrazide. The preparation method is characterized by comprising steps as follows: S1: hexanediol and strong acidic salt are added to methanol and then subjected to heating reflux for an esterification reaction, dimethyl oxalate is produced, and the esterification reaction is performed; S2: hydrazine hydrate is added, dimethyl oxalate prepared in the step S1 is added to hydrazine hydrate, and methanol is added for a hydrazine substitution reaction; S3: impurities are removed. The yield of adipic acid dihydrazide can be increased, and the content of free hydrazine is reduced.

Description

technical field [0001] The invention belongs to the technical field of chemistry, in particular to a method for preparing adipic acid dihydrazide. Background technique [0002] At present, adipate dihydrazide is a white crystalline powder, a bifunctional compound, and is an important cross-linking agent. Currently, the existing technology generally adopts a two-step method to synthesize adipate dihydrazide 4. Synthesize crude dimethyl adipate from diacid and methanol, then separate and purify to obtain fine dimethyl adipate, and then react with hydrazine hydrate to prepare adipate dihydrazide. [0003] Adipic acid dihydrazide and diacetone acrylamide are used as monomers for ketohydrazine crosslinking, and the research on the synthesis of adipate dihydrazide is much less than the synthesis and application of diacetone acrylamide. At present, the method of directly reacting adipic acid and hydrazine hydrate to synthesize adipate dihydrazide has a low yield. [0004] Therefo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C241/04C07C243/28
CPCC07C241/04C07C243/28
Inventor 刘立国袁艳华
Owner 潍坊芝麻开门化工有限公司
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