Preparation technology of acetohydroxamic acid

A technology for the preparation of acetohydroxamic acid, applied in the chemical industry, can solve the problems of low conversion rate, difficult industrial production, harsh reaction conditions, etc., and achieve the effect of low production cost

Inactive Publication Date: 2011-03-02
SHANDONG HUAERKANG BIOTECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The common synthesis method at home and abroad is to react ethyl acetate or methyl acetate and hydroxylamine hydrochloride in an organic solvent system, but there are disadvantages such as low conversion rate, harsh reaction conditions, and difficult industrial production.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Embodiment 1: the preparation of acetohydroxamic acid

[0016] In a 100ml three-port glass reactor, add 24g of hydroxylamine hydrochloride, add 33ml of water, stir to dissolve, slowly add 4.5ml of NaOH solution with a concentration of 30% by mass, and adjust the pH of the solution to 5.5. Then 20 g of acetamide and 0.03 g of 4-dimethylaminopyridine were added, and the temperature was controlled at 30° C. and stirred for 2 hours. After the reaction was completed, the temperature was lowered to -5°C, NaCl crystals were precipitated, and filtered. The filtrate was concentrated to dryness in vacuo to obtain 30 g of acetohydroxamic acid crystals with a content of 82.7% and a yield of 97.7%.

Embodiment 2

[0017] Embodiment 2: the assay method of acetohydroxamic acid

[0018] ① Prepare 0.1mol / L HCl solution

[0019] ② Prepare 2% ferric chloride solution, take 2g of ferric chloride (calculated as anhydrous matter), add 100ml of 0.1mol / L HCl solution, dissolve, filter, and set aside.

[0020] ③Preparation of standard solution: Accurately weigh 0.3g of acetylhydroxamic acid standard (provided by Zhejiang Quzhou New Future Chemical Co., Ltd., content 98%), put it in a 100ml volumetric flask, add water to dissolve, dilute to the mark, and shake well .

[0021] ④ Draw the working curve: Accurately draw the standard solution 0.4, 0.6, 0.8, 1.0, 1.2, 1.4ml, put it in a 50ml colorimetric tube, add 10ml of 0.1mol / L HCl and 1ml of 2% ferric chloride solution respectively, Add water to 50ml, shake well, wine red color will appear immediately, take blank solution as reference solution, measure absorbance at 500nm wavelength, and draw working curve.

[0022] ⑤Take an appropriate amount of ...

Embodiment 3

[0023] Embodiment 3: the preparation of acetohydroxamic acid

[0024] In a 50-liter glass-lined reactor, add 10Kg of hydroxylamine hydrochloride, add 15Kg of water, stir to dissolve, slowly add 1780ml of 30% NaOH solution by mass, adjust the pH of the solution to 5.6, then add 8.5Kg of acetamide and 20g of 4-di Aminopyridine. Stir the reaction at 28°C to 30°C for 2.5 hours, cool to -4°C, precipitate NaCl crystals, filter to remove NaCl, concentrate the filtrate to dryness in vacuo, and then vacuum dry at 65°C for 4 hours to obtain acetylhydroxamic acid crystals 12.5 Kg, content 81.8%, yield 96.2%.

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PUM

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Abstract

The invention discloses a preparation technology of acetohydroxamic acid, which comprises the following steps: hydroxylamine hydrochloride is dissolved into water; caustic soda liquid is added to neutralize hydrochloric acid in the hydroxylamine hydrochloride so as to dissociate hydroxylamine; acetamide and a catalyst of 4-dimethylamino pyridine are added for carrying out synthetic reaction to obtain acetohydroxamic acid aqueous solution; the aqueous solution is dried through vacuum concentration to obtain acetohydroxamic acid crystal with the mass percentage of above 80%; and the aqueous solution can be also directly compounded with light calcium carbonate and then dried to obtain a product applicable to a feed additive, and the product has wide use in the fields of animal husbandry, agriculture and the like. The invention has the advantages that reaction can be carried out with water as a reaction medium under the conditions of room temperature and normal pressure; the conversion rate reaches above 95%; the production cost is low; and industrial production is easily carried out.

Description

technical field [0001] The invention relates to a preparation process of acetylhydroxamic acid, which belongs to the field of chemical industry. Background technique [0002] Acetohydroxamic acid (AHA) is widely used in medicine, animal husbandry, agriculture, and environmental protection. As a rumen microbial urease inhibitor, AHA has strong specificity, can slow down the decomposition rate of urea, increase the amount of microbial protein synthesis, thereby improving the production level of ruminants, and saving protein feed at the same time. It has been listed in the national feed additive category. The common synthesis method at home and abroad is to react ethyl acetate or methyl acetate and hydroxylamine hydrochloride in an organic solvent system, but both have the disadvantages of low conversion rate, harsh reaction conditions, and difficult industrial production. Contents of the invention [0003] The object of the present invention is to provide a kind of preparat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C259/06A23K1/16A23K20/10
Inventor 聂善文张新华何新丽
Owner SHANDONG HUAERKANG BIOTECH
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