Abstract: A method for preparing a dialkyloxydianhyrohexitol (dimethylisosorbide) composition by etherification of dianhydrohexitol (isosorbide). The aim is to achieve a “clean” method that avoids the use of a methylation agent such as dimethyl sulfate or methyl chloride, which generates stoechiometric quantities of salts, or expensive dialkyl-carbonates, wherein only one of the two methyl groups participates in the preparation of mixed isosorbide ethers. The method involves using at least one O-alkylation agent and a catalyst including an acid or an acid salt, preferably a catalyst having Lewis or BrØnsted acid properties. A device for carrying out the method wherein the device includes a vaporization oven and a reaction oven is also described.

Abstract: A method for preparing a dialkyloxydianhyrohexitol (dimethylisosorbide) composition by etherification of dianhydrohexitol (isosorbide). The aim is to achieve a “clean” method that avoids the use of a methylation agent such as dimethyl sulfate or methyl chloride, which generates stoechiometric quantities of salts, or expensive dialkyl-carbonates, wherein only one of the two methyl groups participates in the preparation of mixed isosorbide ethers. The method involves using at least one O-alkylation agent and a catalyst including an acid or an acid salt, preferably a catalyst having Lewis or BrØnsted acid properties. A device for carrying out the method wherein the device includes a vaporization oven and a reaction oven is also described.

Abstract: A carbon fiber fabric having large specific surface area is made using a rayon precursor, and a catalyst is fixed on the fabric by impregnation or by cationic exchange. The carbon fiber fabric has pores with a mean size lying in the range 0.3 nm to 3 nm, a carbon content greater than 99%, and a high density of functional groups per unit area which favors the dispersion of metal catalyst in the form of fine particles and which is good for highly selective catalytic reactions in fine chemistry.

Abstract: A process for the preparation of the enol lactone of 2-oxocyclohexylidene acetic acid wherein(i) glyoxylic acid is allowed to react with cyclohexanone in the presence of a halogen acid in order to obtain a crude reaction product B1, then(ii) said crude reaction product B1 is allowed to react, after solubilisation in an organic solvent, in the presence of a strong acid soluble in said organic solvent or of strongly acid resins, in order to obtain the enol lactone of 2-oxocyclohexylidene acetic acid which is isolated if desired,and application to the preparation of 2-coumaranone.

Abstract: Preparation process for 2-coumaranone in which glyoxylic acid, in vapor phase, is reacted with cyclohexanone, in the presence of a dehydrogenation catalyst.