Abstract: A process for preparing a 5-halophenol, ortho-substituted by an electron-donating group, is described. Also described, is a process for preparing a sulphonic ester of an ortho-substituted phenol, which is the synthesis intermediate for the ortho-substituted 5-halophenol. The process for preparing a phenol ortho-substituted by an electron-donating group and protected in the form of a sulphonic ester can include reacting a phenol ortho-substituted by an electron-donating group with a sulphonylating agent in the presence of a Lewis acid. The process for preparing a 5-halophenol ortho-substituted by an electron-donating group can include a first step of preparing a phenol ortho-substituted by an electron-donating group and protected in the form of a sulphonic ester, as described above; a second step of halogenating the protected phenol intermediate obtained in the preceding step, in the position para to the electron-donating group; and a third step of deprotecting the sulphonic ester function to hydroxyl.

Abstract: A process for preparing a 5-halophenol, ortho-substituted by an electron-donating group, is described. Also described, is a process for preparing a sulphonic ester of an ortho-substituted phenol, which is the synthesis intermediate for the ortho-substituted 5-halophenol. The process for preparing a phenol ortho-substituted by an electron-donating group and protected in the form of a sulphonic ester can include reacting a phenol ortho-substituted by an electron-donating group with a sulphonylating agent in the presence of a Lewis acid. The process for preparing a 5-halophenol ortho-substituted by an electron-donating group can include a first step of preparing a phenol ortho-substituted by an electron-donating group and protected in the form of a sulphonic ester, as described above; a second step of halogenating the protected phenol intermediate obtained in the preceding step, in the position para to the electron-donating group; and a third step of deprotecting the sulphonic ester function to hydroxyl.

Abstract: A process for the production of carboxylic acids by oxidation of a hydrocarbon by oxygen or a gas containing oxygen and notably to the oxidation of cyclohexane to give adipic acid; the subject process entails a stage of oxidation of the hydrocarbon and at least one stage for extracting the dicarboxylic acids formed from the reaction medium and optionally recycling the unconverted hydrocarbon with oxidation by-products, such as alcohols and ketones, and which also includes a stage of conversion, removal or extraction of the ?,?-hydroxycarboxylic compounds formed during the oxidation stage and converting these compounds into diacids.

Abstract: The invention relates to a method of preparing a high-purity nitrophenol and, more specifically, p-nitrophenol from a nitrohalobenzene. The inventive method comprises the following steps: (a) hydrolysis of a nitrohalobenzene compound by reacting said compound with a base; (b) acidification in order to produce the nitrophenol compound from the salt thereof by means of an acid treatment; (c) crystallisation of the nitrophenol compound obtained; and (d) separation of the product obtained. The invention is characterised in that it also comprises at least the following steps: (e) concentration of the reaction medium after hydrolysis (a) and before acidification (b); and (f) liquid/liquid decantation after acidification (b) and before crystallisation (c), which is intended to eliminate the water phase obtained after acidification (b).

Abstract: The invention relates to a method of preparing a high-purity nitrophenol and, more specifically, p-nitrophenol from a nitrohalobenzene. The inventive method comprises the following steps: (a) hydrolysis of a nitrohalobenzene compound by reacting said compound with a base; (b) acidification in order to produce the nitrophenol compound from the salt thereof by means of an acid treatment; (c) crystallisation of the nitrophenol compound obtained; and (d) separation of the product obtained. The invention is characterised in that it also comprises at least the following steps: (e) concentration of the reaction medium after hydrolysis (a) and before acidification (b); and (f) liquid/liquid decantation after acidification (b) and before crystallisation (c), which is intended to eliminate the water phase obtained after acidification (b).