- Hydroxamic acid and preparation method of hydroxamic acid salt
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The invention discloses a preparation method of hydroxamic acid salt. The preparation method comprises the following steps: mixing organic carboxylic ester, hydroxylamine or/and hydroxylamine salt, acatalyst and an inert solvent; and adding alkali and grinding to obtain the hydroxamic acid salt, and adding acid into the hydroxamic acid salt, grinding, centrifuging or filtering to obtain the hydroxamic acid. The process conditions for producing the hydroxamic acid or the hydroxamic acid salt by a grinding method in the prior art are optimized, the inert solvent diesel oil is used for replacingwater or methanol and the inert solvent is recycled after being subjected to centrifugal separation and simple treatment so that the generation of waste liquid is avoided, the use of toxic solvents is avoided and the operation safety is also greatly improved; besides, the material is in a flowing state during the grinding reaction due to the use of the inert solvent,so that the viscous material is prevented from adhering to the inner wall of the reaction container and the grinding medium, the reaction is more uniform, the temperature is more controllable, the reaction efficiency is greatly improved, the discharging is more convenient and the industrial production is facilitated.
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Paragraph 0076; 0077
(2020/04/06)
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- Carboxylic ester oximationmethod
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The invention discloses method for preparing(iso)hydroxamic acid salt or (iso)hydroxamic acid. The method for preparing (iso)hydroxamic acid salt or (iso)hydroxamic acidcomprises the steps that analkali, a hydroxylamine salt, and an organic carboxylic acid ester are directly subjected to hybrid reaction without an extra solvent, and thusan (iso) hydroxamic acid salt product is obtained; and or after the reaction is completed, a reaction system is cooled, an acid is added to the reaction system to obtain (iso)hydroxamic acid.According to themethod for preparing (iso)hydroxamic acid salt or (iso)hydroxamic acid,the (iso)hydroxamic acid salt or the (iso)hydroxamic acidcan be obtainedwith near atomic economy without additional organic solvents or water being added, environment-friendly effectis achieved, simpleness and efficiency are achieved, and industrial production is advantageous.
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Paragraph 0055-0057; 0060-0062; 0069-0071
(2019/11/04)
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