Rhone-poulenc Chimie

Rhone-poulenc Specialites Chimiques

Rhone-poulenc Systemes

Michel Crochemore

Michel Alas

Pascal Barthelemy

Bernard Langlois

Isabelle Storet

Christophe Rochin

Claude Ceintrey

Michel Casado

Cyclic ketones, notably cyclopentanone and 2,2-dimethylcyclopentanone, are simply, economically and efficiently prepared, even on an industrial scale, by decarboxylating/cyclizing a dicarboxylic acid, in liquid phase, in the presence of a catalytically effective amount of a metal or compound thereof selected from among boron, aluminum, gallium, indium, thallium, tin, antimony, bismuth, molybdenum, rubidium, cesium and vanadium.

Preparation of cyclic ketones

Mono- or polycarboxylic acid esters are prepared by reacting a salt of such carboxylic acid with an organic halocompound, e.g., a (cyclo)alkyl, (cyclo)alkenyl, aryl or aralkyl halide, in an aqueous reaction medium, in the presence of a catalytically effective amount of a phase transfer catalyst, for example an onium salt.

Esterification of carboxylic acid salts

The vanillic acid esters, for example, methyl or ethyl vanillate, are effective perfuming or olfactory agents for a wide variety of compositions, substrates and articles, whether perfumes, skin- and haircare products, cosmetics, shaving preparations, toiletries, deodorants and antiperspirants, room deodorizers, etc.

Vanillic acid ester perfuming agents

Cyclic ketones, notably cyclopentanone and 2,2-dimethylcyclopentanone, are simply, economically and efficiently prepared, even on an industrial scale, by decarboxylating/cyclizing a dicarboxylic acid, in liquid phase, in the presence of a catalytically effective amount of a condensed or uncondensed neutral phosphate.

A process for the preparation of 2,2-difluoro-1,3-benzodioxole from 2,2-dichlorol,3-benzodioxole. 2,2-Difluoro-1,3-benzodioxole is prepared by reaction of 2,2-dichloro-1,3-benzodioxole with potassium fluoride in the presence of an effective quantity of a catalyst selected from potassium hydrogen fluoride, sodium hydrogen fluoride, cesium hydrogen fluoride, rubidium hydrogen fluoride, and quaternary ammonium hydrogen fluoride. 2,2-Difluoro-1,3-benzoxodiole is an intermediate compound which is used particularly for the preparation of products for agricultural chemistry and for the synthesis of pharmaceutical products.

Process for the preparation of 2,2-difluoro-1,3-benzodioxole

A process for the preparation of aromatic aldehydes by formylation of aromatic compounds in liquid hydrofluoric acid in the presence of boron trifluoride.

Process for the preparation of aromatic aldehydes

3-Methoxy-4,5-methylenedioxybenzaldehyde is facilely and improvedly prepared by reacting 4,5-dihydroxy-3-methoxybenzaldehyde with a dihalomethane in a two-phase reaction medium and at a pH of from 7 to 12.

Preparation of 3-memory-4,5-methylenedioxybenzaldehyde

3,4,5-Trialkoxybenzaldehydes, notably 3,4,5-triamethoxybenzaldehyde, are prepared by hydrolyzing 5-bromo-4-hydroxy-3-methoxybenzaldehyde with an alkali metal hydroxide, in water and in the presence of a copper catalyst, and then directly sequentially (i.e., without separating any reaction intermediates) etherifying the 4,5-dihydroxy-3-methoxybenzaldehyde thus produced with a lower alkyl halide, in an aqueous medium and at a pH maintained at a value of from 6 to 12, optionally in the presence of a catalyst.

Preparation of trialkoxybenzaldehydes

Novel N-[(meth)allyloxy-mono-/di(meth)allylphenyl]maleimides, in admixture with at least one N-[(meth)allyloxyphenyl]maleimide, are reacted with at least one bismaleimide, and optionally a hydroxylated organosilicon compound, in the presence of an imidazole compound, to obtain mechanically improved thermosetting imido copolymerizates well adapted for the production of, e.g., coatings, adhesive bondings, laminates and composites.

Novel n[meth)allyloxy(meth)allylphenyl]maleimides and thermosetting

N,N'-bis(2-hydroxyethyl)oxamide is facilely prepared, e.g., in finely divided crystalline form, by reacting an alkyl oxalate with ethanolamine in an aqueous reaction medium.

Growing community of inventors

Chaponost, France

Michel Crochemore