Rhone-poulenc Chimie

Rhodia Chimie

Rhone-poulenc Rorer S.a.

Michel Gubelmann

Jean-Michel Popa

Philippe-Jean Tirel

Christian Allandrieu

Claude Doussain

Michel Costantini

Michel Alas

Christian Maliverney

Helene Pernot

Laurent Gilbert

Anne-Marie Le Govic

Eric Garcin

Jean-Pierre Lecomte

Christophe Rochin

Elisabeth Bordes

Alain Aubry

Emmanuel Dos Santos

Laurent Tessier

Pascal Mettvier

Christophew Rochin

Philipe-Jean Tirel

The aliphatic carboxylic acids, e.g., acetic acid, are selectively prepared, even on an industrial scale, by controlledly oxidizing the corresponding alkanes, e.g., ethane, with a source of oxygen, in the presence of a catalytically effective amount of an advantageously supported heteropolyacid catalyst having the formula (I):

Preparation of aliphatic carboxylic acids in the presence of

A process for producing anhydrides by passing a solution of the acid, preferably an organic polyacid, which is to undergo anhydridation over an acidified clay and a process for producing the catalysts therefor.

Process for producing acid anhydrides

Process for treating a material comprising a polymer by hydrolysis

The present invention relates to a process for the preparation of carboxylic acids by controlled oxidation of the corresponding alkanes. The process according to the invention consists in reacting the alkane with a source of oxygen, the reaction being performed in the presence of a catalyst in which the active phase is based on vanadium, titanium, molybdenum, phosphorus and oxygen.

Process for the preparation of carboxylic acids by controlled oxidation

Branched saturated dinitrile byproducts, e.g. 2-methylglutaronitrile, 2-ethylsuccinonitrile and mixtures thereof, are converted into useful ethylenic nitriles by dehydrocyanating same, in vapor phase, in the presence of an at least partially acidified cation exchange substrate, notably a molecular sieve, clay, acid oxide or lamellar phosphate.

Dehydrocyanation of aliphatic dinitriles

Optionally substituted p-aminophenol compounds, easily converted into the N-acylated derivatives thereof, are prepared by hydrogenating the corresponding nitrobenzene, in solution in a saturated aliphatic monocarboxylic acid, notably acetic acid, in the presence of an effective amount of a protonic acid.

Preparation of p-aminophenols

The present invention relates to novel .alpha.-hydroxyacids of the general formula (I), to the process of preparing them and to the use thereof as intermediates allowing access to homologous lower aldehydes (such as prenal or citral) by oxidative decarboxylation. ##STR1##

.alpha.-hydroxy-acids, preparation process and the use thereof

Process for producing itaconic anhydride

The phenols and phenol ethers are hydroxylated by reaction with hydrogen peroxide in the presence of a catalytically effective amount of a titanozeosilite, advantageously a silicon oxide/titanium oxide MFI zeolite having the general formula:

Hydroxylation of phenols/phenol ethers

The phenols and phenol ethers, e.g., phenol itself, are effectively hydroxylated by reacting hydrogen peroxide therewith, in the presence of a catalytically effective amount of titanium dioxide.

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,

Mono-, di- and triphenols are selectively monomethylated by reaction with para-dimethoxybenzene in the presence of a catalytically effective amount of an acid catalyst.

Selective monomethylation of phenolic compounds

The bis-(N-carboalkoxyanilino)methanes, optionally in the presence of at least one alkyl N-phenylcarbamate, are selectively rearranged into methylenedi(phenylurethane), MDU, in the presence of an effective amount of hydrofluoric acid.

Preparation of methylenedi (phenylurethane)

Methylenedi(phenylurethane), MDU, is selectively prepared by condensing an alkyl N-phenylcarbamate with a methylenating agent, e.g., formaldehyde or a precursor thereof, in the presence of a catalytically effective amount of the protonic acid, hydrofluoric acid.

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Lyons, France

Michel Gubelmann