Abstract: Metallic dihydroxybenzenedisulfonates are prepared, preferably from alkaline metals, from corresponding dihydroxybenzenedisulfonic acids, by reacting the dihydroxybenzenedisulfonic acid present in a sulfuric medium with an adequate amount of a salt including a sulfate or hydrogenosulfate anion.

Abstract: Metallic dihydroxybenzenedisulfonates are prepared, preferably from alkaline metals, from corresponding dihydroxybenzenedisulfonic acids, by reacting the dihydroxybenzenedisulfonic acid present in a sulfuric medium with an adequate amount of a salt including a sulfate or hydrogenosulfate anion.

Abstract: The present invention relates to the use of a stabilising composition free of derivatives of 6-aminouracyl or 6-aminothiouracyl type, and comprising at least one ?-diketone bearing two aromatic nuclei, at least one of which bears at least one substituent on one of the two orthopositions or on the paraposition; the said substituent being chosen from —R, —OR, —SR, —COOH, —O—CF3 and —S—CF3 radicals, in which formulae R is an alkyl radical. The invention also relates to halogenated polymers comprising such a stabilising composition.

Abstract: The present invention relates to the use of a stabilising composition free of derivatives of 6-aminouracyl or 6-aminothiouracyl type, and comprising at least one &bgr;-diketone bearing two aromatic nuclei, at least one of which bears at least one substituent on one of the two orthopositions or on the paraposition; the said substituent being chosen from —R, —OR, —SR, —COOH, —O—CF3 and —S—CF3 radicals, in which formulae R is an alkyl radical. The invention also relates to halogenated polymers comprising such a stabilising composition.

Abstract: The invention concerns a novel method for preparing tetrakis(pentafluorophenyl)borate derivatives of general formula MB(C6F5)4, M being selected among Na+, Li+, or K+, wherein: (a) a C6F5X solution, X being selected among H, Cl, Br or I, in anhydrous butylic ether is contacted with an alkyllithium, the mol ratio of C6F5X/alkyllithium being 1 to 1.1, and the alkyl radical, linear or branched comprising 1 to 10 carbon atoms; (b) the resulting product is contacted with previously non-dissolved BR3, R, identical or different being selected among a chlorine atom, a fluorine atom, a bromine atom, an alkoxy radical comprising between 1 and 4 carbon atoms.

Abstract: The invention concerns a novel method for preparing tetrakis(pentafluorophenyl)borate derivatives of general formula MB(C6F5)4, M being selected among Na+, Li+, or K+, wherein: (a) a C6F5X solution, X being selected among H, Cl, Br or I, in anhydrous butylic ether is contacted with an alkyllithium, the mol ratio of C6F5X/alkyllithium being 1 to 1.1, and the alkyl radical, linear or branched comprising 1 to 10 carbon atoms; (b) the resulting product is contacted with previously non-dissolved BR3, R, identical or different being selected among a chlorine atom, a fluorine atom, a bromine atom, an alkoxy radical comprising between 1 and 4 carbon atoms.

Abstract: The invention concerns a novel method for preparing tetrakis(pentafluorophenyl)borate derivatives of general formula MB(C6F5)4, M being selected among Na+, Li+, or K+, wherein: (a) a C6F5X solution, X being selected among H, Cl, Br or I, in anhydrous butylic ether is contacted with an alkyllithium, the mol ratio of C6F5X/alkyllithium being 1 to 1.1, and the alkyl radical, linear or branched comprising 1 to 10 carbon atoms; (b) the resulting product is contacted with previously non-dissolved BR3, R, identical or different being selected among a chlorine atom, a fluorine atom, a bromine atom, an alkoxy radical comprising between 1 and 4 carbon atoms.

Abstract: The halogenation of a compound of formula (1) or formula (2′), wherein Q is an NH2 group optionally in the form of an addition salt, or an NHCOCH3 group, and X is a halogen atom, using a compound of formula X2, in a solvent selected from an anhydrous halogenated hydrocarbon, a mixture of water and a halogenated hydrocarbon and optionally the compound of formula (1) itself, gives a 2-amino or 2-acetamido trifluoromethylbenzene halogenated in the 5 position of the benzene ring.

Abstract: This invention relates to a method for the preparation of a compound of formula I ##STR1## comprising the steps consisting in: a) optionally reacting a compound of general formula II: ##STR2## with a nitration reagent b) reducing the compound obtained in a)c) subjecting the compound obtained in b) to a dehydrochlorination in order to obtain the compound of formula I: andd) isolating the compound obtained in step c) from the reaction mixture.

Abstract: A method for C-alkylating a hydroxylated aromatic compound having at least one hydrogen atom in the ortho or para position relative to the hydroxyl grouping, wherein the aromatic compound is exposed to a proton acid and a compound causing the formation of a carbo-cation in the presence of the acid, and the reaction is performed in the presence of a solvent consisting of a water-alcohol pair.