Improved production method for salicylhydroxamic acid

A technology of salicylic hydroxamic acid and its production method, which is applied in the field of improved production of salicylic hydroxamic acid, can solve the problems of high hazard of formaldehyde, low utilization rate of raw materials, and high hazard of methanol, so as to reduce rearrangement reactions, improve utilization rate, and reduce The effect of dissolved oxygen oxidation rate

Inactive Publication Date: 2009-09-02
SHANGHAI SECOND POLYTECHNIC UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, a large amount of excess hydroxylamine and alkali are required in the reaction process of this process, the utilization rate of raw materials is low, and other pollutants are produced in the production process, among which methanol is more harmful, and oxidized formaldehyde is even more harmful

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Mix 76.5g of hydroxylamine hydrochloride into a 15% hydroxylamine hydrochloride solution, add it to the reaction vessel, adjust the pH value of the reaction system to 12.0 with a 20% sodium hydroxide solution, heat to 33-35°C and keep it stable, add an emulsifier Immediately, slowly add 152.0g of methyl salicylate stock solution dropwise to the reaction container, and at the same time dropwise add 10-15% sodium hydroxide solution to keep the pH of the reaction system stable at around 12.0. After the solids in the solution are dissolved, keep warm Static reaction for 2 hours, adjust the pH of the reaction system to 4.0-5.0 with concentrated hydrochloric acid, age at 25°C for 2 hours, filter to obtain 132.19g of salicylic hydroxamic acid solid, and the yield of methyl salicylate is 86.4%.

Embodiment 2

[0016] 76.5g of hydroxylamine hydrochloride was made into 20% hydroxylamine hydrochloride solution, added to the reaction vessel, with a concentration of 25% sodium hydroxide solution, the pH of the reaction system was adjusted to 12.0, heated to 35-38°C and kept stable, adding an emulsifier, Immediately, slowly add 152.0g of methyl salicylate stock solution dropwise to the reaction vessel, and at the same time add dropwise 10-15% sodium hydroxide solution to keep the pH of the reaction system stable at around 12.0. After the solids in the solution are dissolved, keep warm After static reaction for 2 hours, adjust the pH of the reaction system to 4.0-5.0 with concentrated hydrochloric acid, age at 30° C. for 2 hours, filter to obtain 130.25 g of salicylic hydroxamic acid solid, and the yield of methyl salicylate is 85.13%.

Embodiment 3

[0018] 80.0g of hydroxylamine hydrochloride is made into a 20-30% hydroxylamine hydrochloride solution, added to the reaction vessel, and the pH of the reaction system is adjusted to 12.0 with a concentration of 15-30% sodium hydroxide solution, heated to 33-38°C and maintained stable, Add the emulsifier, and immediately drop 152.0g of methyl salicylate stock solution slowly into the reaction vessel, and simultaneously add 10-20% sodium hydroxide solution dropwise to keep the pH of the reaction system stable at about 12.0 throughout the reaction process. After the solids in the solution were dissolved, keep the temperature still and react for 2 hours, adjust the pH of the reaction system to 4.0-5.0 with concentrated hydrochloric acid, age for 2 hours at 25°C, and filter to obtain 132.19g of salicylic hydroxamic acid solid, methyl salicylate The ester yield was 86.4%.

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Abstract

The invention relates to an improved production method for salicylhydroxamic acid. The method is characterized in that a metered hydroxylamine solution is added into a reaction vessel; the PH value of a reaction system is adjusted around 12.0 by a strong alkali solution; the reaction system is heated to a temperature of between 33 and 38 DEG C, added with an emulsifier and dripped with a stock solution of menthyl salicylate and a strong alkali solution; the PH of the reaction system is always stabilized around 12.0; after solid in the solution is dissolved, the solution is kept at the temperature and performs arrest reaction; subsequently, the PH is adjusted to be between 4.0 and 5.0 by using acid; and the solution is aged at the temperature of between 20 and 30 DEG C and filtered to obtain salicylhydroxamic acid solid. As the method reduces the using level of hydroxylamine, alkali and the acid in the process of acidification simultaneously, the method improves the yield of the salicylhydroxamic acid and effectively reduces the discharge amount of methanol, thereby reducing environmental pollution.

Description

technical field [0001] The invention relates to an improved production method of salicylic hydroxamic acid, in particular to a production method of using methyl salicylate and hydroxylamine to undergo ammonolysis reaction under strong alkali conditions, and then acidifying the reaction liquid to obtain salicylic hydroxamic acid. Background technique [0002] Hydroxamic acid is a high-efficiency collector widely used in the mineral processing industry in recent years. It is mainly used as a collector or extractant for rare earth ore, copper oxide ore, lead-zinc oxide ore, gold ore, kaolin, etc., as an intermediate in organic synthesis Wait. Due to its special structure and corresponding physical and chemical properties, hydroxamic acid is also used as an important metal complexing agent. Since hydroxamic acid is a weak proton donor, it is used in enzyme inhibitors, siderophore proteins, DNA cutting, Metallonucleases and drug delivery systems have been widely used. [0003] ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C259/10B03D1/01B03D101/02B03D103/04
Inventor 周玉林袁昊
Owner SHANGHAI SECOND POLYTECHNIC UNIVERSITY
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