β-D-5 thioxylose derivatives, preparation method and therapeutic use

Method for the preparation of a compound of formula I in which R is a C2-C3-hydroxyalkyl group, which comprises the carbonation reaction of 4-methyl-2-oxo-2H-1-benzopyran-7-yl 5-thio-β-D-xylopyranoside of formula II:

• with a halogenoformate of formula IIIbis:
• in which R″ is a C2-C3-hydroykyl group with its OH function protected and Hal is a halogen atom as defined above, and the resulting compound is then subjected to a deprotection reaction of the OH function of the hydroxyalkyl group by reaction with hydrofluoric acid solution to give the compound of formula I in which R is a C2-C3-hydroxyalkyl group, in an anhydrous solvent, in the presence of an aprotic base, at a temperature of 10° C. to 80° C. for a period of 1 to 10 hours.

A method of treating disorders of the venous circulation comprising administration of a therapeutically effective amount of a compound of formula I:

• in which R is a linear, branched or cyclic C1-C5-alkyl group, a monounsaturated C2-C3-alkene group, a C2-C3-hydroxyalkyl group or a C3-C6-alkoxyalkyl group.