Abstract:
The invention concerns a method for preparing an oxysulphide and fluorinated derivative, said method comprising the reacting, in the presence of an organic solvent, of: i) at least one compound of formula Ea-COOR (I), in which Ea represents the fluorine atom or a group having 1 to 10 carbon atoms chosen from fluoroalkyls, perfluoroalkyls and fluoroalkenyls and R represents hydrogen, a monovalent cation or an alkyl group, and ii) a sulphur oxide, said method being such that the initial molar ratio (sulphur oxide/compound of formula (I)) is less than 0.4 and the concentration of sulphur oxide dissolved in the reaction medium is kept constant for the entire duration of the reaction to a value of between 0.2% and 3% by weight by means of continually adding said sulphur oxide to the reaction medium.
Abstract:
The present invention relates to a new process of vanillin production from a substrate by bioconversion and that allows a continuously producing and removing vanillin from the fermentation broth as it is formed. In particular, the invented process advantageously allows to reduce the residence time of vanillin in the fermenter and to maintain the vanillin concentration, in the fermentation broth, below its toxic level for the microorganism.