Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a 1-nitro-2-naphthol derivative by which the 1-position of 2-hydroxynaphthalene-3,6-dicarboxylic acid or a derivative thereof is effectively and selectively nitrated. SOLUTION: The method for producing the 1-nitro-2-naphthol derivative represented by general formula [II] (wherein, Y 1 and Y 2 represent each an ester group or the like; and X represent a halogen) comprises the following. A 2-naphthol derivative represented by general formula [I] is reacted with a nitrating agent using an aliphatic carboxylic acid as a solvent. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for reasonably producing a substituted halogenated benzene compound, especially a 2,6-dialkyl(or aryl)-4-substituted halogenated benzene compound, useful as an intermediate for medicines or agrochemicals. SOLUTION: This method for producing the substituted halogenated benzene compound comprises reacting a substituted (thio)phenol compound or (thio) phenolate compound represented by general formula (I) with a halogenating agent represented by general formula (II).
Abstract:
PURPOSE:To safely produce the subject compound from an aqueous solution of 3,5-dichloro-4-ethyl-2-hydroxybenzenesulfonic acid and an aqueous solution of nitric acid in high purity and yield by reusing a filtrate or water layer obtained by separating the objective compound after nitration reaction. CONSTITUTION:The subject compound useful as an intermediate for a cyan coupler for color photography, etc., is produced by sulfonating preferably 4- chloro-3-ethylphenol, chlorinating the resultant 5-chloro-4-ethyl-2-hydroxybenzenesulfonic acid and nitrating an aqueous solution of the obtained 3,5- dichloro-4-ethyl-2-benzenesulfonic acid with an aqueous solution of nitric acid having an acid concentration of preferably 2-70wt.%. In the above process, the filtrate or water layer obtained by filtering or separating the objective compound produced by the nitration reaction is reused as a part or total of the nitration reaction medium. The induction period can be shortened, the safety and yield can be remarkably improved and the objective compound can be produced on an industrial scale at a low cost by this process.