346-34-9Relevant articles and documents
Industrial preparation method of high-purity 4-fluoroisatin
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Paragraph 0010-0015, (2020/01/25)
The invention discloses an industrial preparation method of high-purity 4-fluoroisatin. The preparation method comprises the steps: firstly, reacting m-fluoroaniline with hydroxylamine hydrochloride and trichloracetic aldehyde, and carrying out condensation to prepare oximide acetanilide; then, cyclizing concentrated sulphuric acid, and carrying out hydrolysis to prepare a mixture of 4-fluoroisatin and 6-fluoroisatin; and then, separating and purifying the mixture of 4-fluoroisatin and 6-fluoroisatin by using an alkali solution acidolysis method to obtain high-purity 4-fluoroisatin. The industrial preparation method is simple in process, high in yield, low in production cost and suitable for industrial production.
Utilizing Solubility differences to achieve regiocontrol in the synthesis of substituted quinoline-4-carboxylic acids
Lindsay-Scott, Peter J.,Barlow, Helen
supporting information, p. 1516 - 1520 (2016/06/14)
A practical method for the regiocontrolled synthesis of substituted quinoline-4-carboxylic acids is described. Solubility differences between the product quinoline regioisomers enable their facile separation, thus avoiding any challenging chromatographic purifications and allowing access to highly substituted quinoline compounds in three steps from commercially available anilines.
Novel synthesis of 4-or 6-substituted indirubin derivatives
Zhang, Aiying,Yu, Mingfeng,Lan, Tian,Liu, Zenglu,Mao, Zhenmin
experimental part, p. 3125 - 3134 (2010/12/24)
A simple and convenient route for synthesis of a series of 4-or 6-substituted indirubin derivatives by oxidation and subsequent condensation of indoxyl and isatin is described. Acidic reaction conditions are crucial to the condensation of 4-substituted derivatives, whereas for the condensation of 6-substituted derivatives, both acidic and basic conditions work well. Copyright Taylor & Francis Group, LLC.