Rhone-Poulenc Chimie

Rhodia Chimie

Philippe-Jean Tirel

Michel Gubelmann

Laurent Gilbert

Claude Doussain

Michel Spagnol

Jean-Michel Popa

Michel Alas

Anne-Marie Le Govic

Helene Pernot

Alain Roustan

Henri Guillot

Alain Sigismondi

Marcelle Janin

The invention concerns a method for displacing, at least partially, an aniline from its chlorhydrate, characterized in that said aniline is selected among anilines whereof the conjugate acid has a pKa not more than 6 and in that it consists in a step wherein it is subjected at a temperature not less than 50&deg; C., advantageously about 70&deg; C. to a reaction medium containing said chlorhydrate at least partially dissolved in a weakly polar solvent. The invention is applicable to organic synthesis.

Use of an aniline depleted in electron to release hydrochloric acid present in a reaction mixture and method for displacing, at least partially, an aniline from its chlorhydrate

Acylation method for an aromatic compound

Carbocyclic/aliphatic ethers, for example anisole, quaicol, guaethol, p-methoxyphenol and ethylene dioxybenzene, are selectively prepared, in good yield, by reacting a phenolic compound, for example a phenol, hydroquinone, pyrocatechin, naphthol, or the like, with an alcohol, for example methanol, ethanol, isopropanol, ethylene glycol, etc., in gaseous phase, in the presence of a catalytically effective amount of a trivalent rare earth metal orthophosphate, for example a lanthanum, cerium or samarium orthophosphate, optionally doped with an alkali or alkaline earth metal, preferably cesium.

O-alkylation of phenolic compounds via rare earth orthophosphate

Citraconic anhydride is prepared in a single step by heating itaconic acid, optionally in an inert organic solvent medium, in the presence of a catalytically effective amount of an at least partially organic acid/base catalyst compound having a pKa ranging from 4 to 10, in particular a salt catalyst such as pyridinium tosylate, itaconate or hydrochloride, ammonium itaconate, or phosphinium hydrobromide.

Preparation of citraconic anhydride

The alkyl hydroquinones, e.g., methyl hydroquinone (a useful intermediate in the preparation of the monomer methyl hydroquinone diacetate, itself used for the synthesis of thermotropic polymers), are prepared by reacting (C-alkylating) hydroquinone or a monoether thereof with a lower alkanal, in the vapor phase, with a catalytically effective amount of at least one solid metal oxide.

C-alkylation of hydroquinone or monoethers thereof

The invention relates to chemical compounds and their use as catalysts in the solvolysis of alkyl halides. The chemical compounds, when dry, have formula (I):

Chemical compound containing alkali metals or alkaline earth metals,

A process for the preparation of halophenols. A halobenzene is brought into contact with nitrous oxide on an acidified zeolite.

Process for the preparation of halophenols

Phenol is prepared by directly hydroxylating benzene with nitrous oxide, preferably in vapor phase, on a substrate of acidified zeolite particulates, advantageously ZSM-5 zeolite particulates, and such acidified zeolite particulates having a molar ratio SiO.sub.2 /Al.sub.2 O.sub.3 of greater than about 90, preferably up to 500.

Preparation of phenol by direct hydroxylation of benzene

Polyhydroxybenzenes, e.g., the dihydroxybenzenes, are prepared by directly hydroxylating a phenol with nitrous oxide, preferably in vapor phase, on a substrate of acidified zeolite particulates, advantageously ZSM-5 zeolite particulates, and such acidified zeolite particulates advantageously having a molar ratio SiO.sub.2 /Al.sub.2 O.sub.3 of greater than about 90, preferably up to 500.

Preparation of polyhydroxybenzenes by direct hydroxylation of phenols

A process for the preparation of trifluoroethanol by hydrolysis, in the gas phase, of chlorotrifluoroethane. A gaseous mixture of 1-chloro-2,2,2-trifluoroethane and water is contacted with a solid catalyst and taken to a temperature greater than 350.degree. C. and preferably between 400.degree. and 500.degree. C. 2,2,2-Trifluoroethanol (TFE) is a trifluorinated alcohol possessing very good thermal stability, which makes it suitable for a certain number of applications, in particular in the synthesis of fluorinated anesthetics, in pharmacology in general, and as a solvent.

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Oullins, France

Philippe-Jean Tirel