Rhodia Chimie

Rhone-poulenc Nutrition Animale

Aventis Animal Nutrition S.a.

Rhodia Pharma Solutions Inc.

Philippe Morel

Pascale Colin

Philippe Leconte

Roland Jacquot

Dominique Horbez

Serge Veracini

Olivier Favre-Bulle

Jay Larrow

Hocine Kabir

Jerome Pierrard

Frederic Kress

Karl Hemberger

Pierre Grenouillet

Christina Garcia-Escomel

Claude De Bellefon

Christophe David

Claude Casse

The invention relates to a method for the preparation of cyclohexanone from cyclohexane. The invention relates more particularly to a method for the production of cyclohexane whose impurity content enables cyclohexanone to be used as a raw material for the production of e-caprolactam. The inventive method consists in treating the mixture of cyclohexanol/cyclohexanone arising from oxidation of cyclohexane by oxygen in a dehydrogenation stage in order to transform cyclohexanol into cyclohexanone and the impurities present such as cyclopentenal. The inventive method makes it possible to obtain highly pure cyclohexanone which is compatible when used as a raw material in the synthesis of e-caprolactam.

Method for the production of cyclohexanone

A method for making a chiral transition metal-ligand catalyst complex that is active in catalyzing stereoselective ring opening reactions includes contacting an asymmetric tetradentate ligand, in an excess of a Br&oslash;nsted acid, with a salt of a first row transition metal, wherein the acidity of the conjugate acid of the salt is the same as or less than the acidity of the Br&oslash;nsted acid, under conditions effective to allow formation of the active chiral transition metal-ligand catalyst complex, and forming a solution of the complex in a water-miscible, protic solvent from which the active complex can be precipitated by the addition of water and adding water to the solution to precipitate at least a portion of the complex.

Active catalysts for stereoselective ring-opening reactions

The invention concerns the upgrading of a by-product of direct synthesis, namely MeSiCl , by vapor phase catalytic hydrogenation of said by-product to obtain MeHSiCl with greater added value. The invention concerns a method for preparing MeHSiCl by catalytic hydrogenation of MeSiCl in the presence of a metal catalyst with high selectivity levels in MeHSiCl economically and without having recourse to drastic and industrially unsuitable conditions. The invention uses a catalyst comprising a bimetal ruthenium/tin catalytic agent. Said catalytic agent is obtained by reacting ruthenium chloride and tin chloride in an acid medium. In practice, the catalyst is formed by a silica powder support impregnated by the ruthenium/tin catalytic agent.

Method for preparing alkyl hydrogeno halosilanes (ahhs) by catalytic hydrogenation

The invention concerns a method for preparing hydrogenated alkylmonosilanes, by catalytic hydrogenolysis, under hydrogen pressure, of halogenoorganopolysilanes, improving known methods, in particular by facilitating implementation, and in terms of cost-effectiveness and performance which are shown by the efficiency of the resulting hydrogenated monosilanes. In said method the starting polysilanes are of the type: (CH,)Cl,Si&mdash;SiCl(CH,),; (CH,)Cl,Si&mdash;SiCl,(CH,); (CH,)Cl,Si&mdash;Si(CH,),; (CH,),ClSi&mdash;SiCl(CH,),; (CH,)Cl,Si&mdash;SiCl(Ch,)&mdash;SiCl,(CH,); (CH,)Cl,Si&mdash;Si(CH,)(SiCH,Cl,)&mdash;SiCl,CH,. The hydrogenated monosilanes CH,H,ClSi; (CH,),HClSi; CH,HCl,Si are obtained by contacting said polysilanes with gaseous hydrogen under pressure, in the presence of a catalytic system AB comprising a hydrogenation catalyst precursor A and an auxiliary B for dissolving precursor A in the reaction medium. Said catalytic system is further characterized in that it is reductant-free.

Preparation of hydrogenosilanes by catalytic hydrogenolysis of polysilanes

Industrial scale process for the preparation of 2-hydroxy-4-methylbutyric acid using a nitrilase

A process for the condensation of an aldehyde with hydrogen cyanide in the presence of a buffer is disclosed. The buffer advantageously allows the condensation reaction to occur at a pH equal to or above 4.0 and in the absence of amines.

Process for the condensation of an aldehyde with hydrogen cyanide

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Chuzelles, France

Philippe Morel