Rhone-poulenc Chimie

Rhone-poulenc Rorer S.a.

Rhodia Chimie

Aventis Pharma S.a.

Jean-Manuel Mas

Laurent Saint-Jalmes

Viviane Massonneau

Gerard Mignani

Yves Bomal

Pascal Metivier

Jean-Noel Denis

Andrew-Elliot Greene

Philippe Karrer

Gerard Forat

G&eacute;rard Forat

Etienne Fleury

Kamel Ramdani

Elie Fouque

Christophe Rochin

Gérard Forat

Saint-Jalmes Laurent

The invention relates to silicon oils, more particularly, to a novel method for the preparation of a silicon oil by polymerization and rearrangement of cyclic siloxanes in the presence of an alkaline catalyst and a co-catalyst which is a cryptand (macroheterobicyclic diamine) acting as a polymerization accelerator.

Method for the preparation of organopolysiloxane by polymerization and rearrangement of cyclic siloxanes

Method for preparing taxane derivatives

Reagent and process which are useful for grafting a substituted difluoromethyl group onto a compound containing at least one electrophilic function

Provided is a process for grafting a substituted difluoromethyl group onto a compound bearing at least one electrophilic substituent, comprising (i) contacting the compound bearing at least one electrophilic substituent with a nucleophilic reagent which comprises (a) a fluorocarboxylic acid having the formula Ea&mdash;CF,&mdash;COOH, wherein Ea is an electron-withdrawing atom or group, the fluorocarboxylic acid being at least partially salified with an organic or inorganic cation and (b) a polar aprotic solvent, and (ii) exposing the resulting medium of reaction to the action of microwave energy.

Method for grafting a substituted difluoromethyl group

Method for synthesizing aryl hydrazine through reduction of a diazo

A compound of the formula I: ##STR1## wherein Ar represents an aryl radical;

Esters of baccatin III and 10-deacetylbaccatin III

The present invention relates to compounds composed essentially of a linear, cyclic or branched polyorganosiloxane having, per molecule, at least 3 siloxy units, including at least one siloxy functional unit of formula: ##STR1## where R.sup.1 represents a C.sub.1 to C.sub.4 alkyl or phenyl radical, X contains an N,N'-di- and/or trisubstituted phenylenediamine functional group, bonded to the silicon via an Si-(hydrocarbon linking unit)-N and/or Si-(hydrocarbon linking unit)-C bond, and a is a number chosen from 0, 1 and 2. The present invention also relates to the use of such compounds as antiozonants for rubbers and in particular for rubber compositions for tires.

Silicone compounds containing a phenylenediamine functional group and

This invention relates to a method of preparing taxane derivatives of general formula (I) by esterification of protected baccatine III or 10-deacetylbaccatine III by means of an acid of general formula (VII), elimination of protection groupings of the ester obtained, and acylation of the amine function of the side chain. In formulae (I) and (VII): Ar stands for aryl, R is hydrogen or acetyl, R.sub.1 is benzoyl or R.sub.2 -CO--O- in which R.sub.2 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, bicycloalkyl, phenyl or heterocyclyl, R.sub.3 and R.sub.4 may be the same or different and represent hydrogen, alkyl, alkenyl, aralkyl, aryl or alkoxy, and R.sub.5 is an alkyl radical substituted by one or more chlorine atoms (2,2,2-trichloroethyl, 2-trichloromethylisopropyl). ##STR1##

Process for preparing taxane derivatives

The invention relates to a reagent which is useful for the synthesis of oxysulphide-containing fluorine-containing organic derivatives by reacting with an oxide of sulphur, especially sulphur dioxide, characterized in that it comprises:

Reagent and process for the synthesis of oxysulphide-containing

The invention relates to a process and a nucleophilic reagent which is useful for grafting a substituted difluoromethyl group onto a compound containing at least one electrophilic function, characterized in that it comprises:

Process for grafting a substituted difluoromethyl group onto a compound

The present invention relates to compounds composed essentially of a linear, cyclic or branched polyorganosiloxane having, per molecule, at least 3 siloxy units, including at least one siloxy functional unit of formula: ##STR1## where R.sup.1 represents a C.sub.1 to C.sub.4 alkyl or phenyl radical, X contains an N,N'-di- and/or trisubstituted phenylenediamine functional group, bonded to the silicon via an Si--(hydrocarbon linking unit)--N and/or Si--(hydrocarbon linking unit)--C bond, and a is a number chosen from 0, 1 and 2. The present invention also relates to the use of such compounds as antiozonants for rubbers and in particular for rubber compositions for tires.

Process for the esterification of baccatin III and of

Disclosed is a compound of formula VII: ##STR1## where Ar represents an optionally substituted phenyl or .alpha.- or .beta.-naphthyl radical; R.sub.3 represents hydrogen, a C.sub.1-4 alkyl radical, a C.sub.2-4 alkenyl radical, an aralkyl radical, or an aryl radical; and R.sub.4 represents hydrogen, a C.sub.1-4 alkyl radical, a C.sub.2-4 alkenyl radical, an aralkyl radical, or an aryl radical; or alternatively R.sub.3 and R.sub.4, together with the carbon atom to which they are linked, form a 4- to 7-membered ring; and R.sub.5 represents an C.sub.1-4 alkyl radical substituted with at least one chlorine atom. The compound of formula VI may be used to manufacture a compound of formula VIII: ##STR2## where Ar, R.sub.3, R.sub.4 and R.sub.5 are defined above; G.sub.1 represents a group protecting the hydroxyl function; and where appropriate, G.sub.2 represents a group protecting the hydroxyl function.

Growing community of inventors

Villeurbanne, France

Jean-Manuel Mas