- A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprises the following steps: A) halogenated acetate with 2, 4 - dichlorophen salt reaction, to obtain 2, 4 - dichlorophenoxy ester; B) 2, 4 - dichlorophenoxy ester under the effects of catalyst hydrolysis reaction, to obtain 2, 4 - dichloro acid; said catalyst is selected from a polyether, a crown ether, quaternary ammonium salt, tertiary amine, [...], pyridine, titanate, inorganic acid, in organic acid one or more. The invention by halogenated acetate with 2, 4 - dichlorophen salt obtained by reaction of 2, 4 - dichlorophenoxy ester, and then in particular under the action of catalyst by hydrolysis reaction of the 2, 4 - dichloro acid. The invention specific reaction line combined with a specific catalyst such that the final preparation to obtain 2, 4 - dichlorophenoxyacetic acid purity and yield is relatively high, few by-products, the reaction route is simple, and is favorable for application. (by machine translation)
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Paragraph 0038; 0039
(2018/09/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: a) reactinghalogenated acetate with 2,4-dichlorophenolate in the presence of a phase-transfer catalyst so as to obtain 2,4-dichlorophenoxyacetate; and b) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, oil-phase halogenated acetate reacts with 2,4-dichlorophenolate under the action of the phase-transfer catalyst to prepare 2,4-dichlorophenoxyacetate, and then 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid and corresponding alcohols. Under the action of the phase-transfer catalyst, few hydrolysis by-products are produced during a reaction, fast reaction speed and high conversion rate and yield are obtained, and the amount of produced waste water is low; so industrial application of the preparation method can be easily implemented.
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Paragraph 0063; 0065; 0066
(2018/09/08)
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- CATALYTIC ROLE OF DIORGANOTIN DICHLORIDE IN ESTERIFICATION OF CARBOXYLIC ACIDS
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Various carboxylic acids were converted into corresponding esters in fair to good yields by diorganotin dichloride-catalysed reaction with alcohols.
- Kumar, Amal K.,Chattopadhyay, Tapas K.
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p. 3713 - 3714
(2007/10/02)
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