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A kind of preparation method of isobutyryl hydrazide

A technology of isobutyric hydrazide and isobutyric acid, applied in the field of isobutyric hydrazide, can solve the problems of difficult control of by-products, harsh preparation conditions of isobutyric hydrazide, and low yield

Active Publication Date: 2018-10-16
苏州敬咨达检测服务有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] In order to overcome the defects of harsh preparation conditions of isobutyric hydrazide in the prior art, uneasy control of by-products, low yield and difficult post-treatment, the invention provides a preparation method of isobutyric hydrazide, using the preparation method, the product High yield and purity, relatively mild conditions, simple post-treatment

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  • A kind of preparation method of isobutyryl hydrazide
  • A kind of preparation method of isobutyryl hydrazide

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preparation example Construction

[0020] The invention provides a kind of preparation method of isobutyric hydrazide, the method comprises:

[0021] (a) Under esterification reaction conditions, react isobutyric acid and methanol in the presence of a catalyst, and distill the mixture obtained by the esterification reaction at 70-120°C to obtain a distillate containing methyl isobutyrate and residual liquid; the water phase in the distillate is separated to obtain an organic phase containing methyl isobutyrate;

[0022] (b) reacting the organic phase containing methyl isobutyrate obtained in step (a) with hydrazine hydrate under the hydrazinolysis reaction conditions.

[0023] Wherein, in the step (a), the molar ratio of the isobutyric acid to methanol is 1:1-2.8.

[0024] According to the present invention, in the step (a), the esterification reaction conditions can be selected conventionally in the art. For example, the esterification reaction conditions include: the temperature may be 60-100° C., preferabl...

Embodiment 1

[0055] This embodiment is used to illustrate the preparation method of the isobutyrhydrazide provided by the present invention

[0056] (a) preparation of methyl isobutyrate

[0057] Step (1-1): Add 39.8g (1.23mol) of methanol, 11.2g (0.112mol) of concentrated sulfuric acid and 100g (1.12mol) of isobutyric acid in the reaction flask in sequence and stir evenly. The temperature rises to 80°C and keeps reflux Status response for 6 hours. Sampling was carried out for chromatographic analysis, and the reaction was stopped when the gas-phase normalized area of ​​isobutyric acid was less than 10%. Then the reaction mixture is subjected to atmospheric distillation at a temperature of 80-110° C., and the distillation can be stopped when no obvious distillate is distilled out to obtain a distillate containing methyl isobutyrate and a residual liquid B1-1. The water phase in the distillate was separated to obtain an organic phase A1-1 containing methyl isobutyrate.

[0058] Step (1-2...

Embodiment 2

[0071] This embodiment is used to illustrate the preparation method of the isobutyrhydrazide provided by the present invention

[0072] (a) preparation of methyl isobutyrate

[0073]Step (2-1): Add 54.36g (1.68mol) of methanol, 9.64g (0.056mol) of p-toluenesulfonic acid and 100g (1.12mol) of isobutyric acid in the reaction flask in sequence and stir evenly, the temperature rises to 70°C, Keep the reflux state to react for 8 hours. Sampling was carried out for chromatographic analysis, and the reaction was stopped when the gas-phase normalized area of ​​isobutyric acid was less than 10%. Then the reaction mixture is subjected to atmospheric distillation at a temperature of 80-110° C., and the distillation can be stopped when no obvious distillate is distilled out to obtain a distillate containing methyl isobutyrate and a residual liquid B2-1. The water phase in the distillate was separated to obtain an organic phase A2-1 containing methyl isobutyrate.

[0074] Step (2-2): Ad...

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Abstract

The invention relates to the field of isobutyric acid hydrazide and discloses an isobutyric acid hydrazide preparing method. The method comprises the steps of 1, making isobutyric acid and methyl alcohol react in the presence of a catalyst under the esterification reaction condition, distilling a mixture obtained from esterification reaction at 70-120 DEG C to obtain distillate containing methyl isobutyrate and residual liquid, and removing aqueous phase in the distillate through separation to obtain an organic phase containing methyl isobutyrate; 2, making the organic phase containing methyl isobutyrate obtained from step 1 react with hydrazine hydrate under the condition of hydrazinolysis. In step 1, the molar ratio of isobutyric acid to methyl alcohol is 1:(1-2.8). By the adoption of the method, the yield and purity of the product isobutyric acid hydrazide are high.

Description

technical field [0001] The invention relates to the field of isobutyric hydrazide, in particular to a preparation method of isobutyric hydrazide. Background technique [0002] Isobutyrhydrazide is an important intermediate for the synthesis of the herbicide amfentrazone, and its structure is as follows: [0003] [0004] The synthetic method of the isobutyric hydrazide reported at present mainly obtains by reacting the ester of isobutyric acid or isobutyric acid with hydrazine hydrate, but the present synthetic method mainly has the following problems: [0005] (1) Use isobutyric acid to directly react with hydrazine hydrate for condensation reaction. Although the yield is high, the reaction requires the use of a catalyst. The commonly used catalyst can be, for example, one of tetraisopropyl titanate, titanium dioxide and aluminum oxide or more. The disadvantages of using catalysts are that it is difficult to separate the catalysts, the requirements for equipment are mo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C241/04C07C243/28
CPCC07C67/08C07C241/04C07C243/28C07C69/24
Inventor 赵建民陈笑宇乔振霍世勇路风奇孙艳伟
Owner 苏州敬咨达检测服务有限公司