Patent ID: 6455738
Filing Date: 2002-09-24
Classification: C07C

Abstract:
A process for the sulfonation of an aromatic compound corresponding to the general formula (I): wherein:A symbolizes a ring forming a monocyclic or polycyclic aromatic carbocyclic compound or a monocyclic or polycyclic aromatic heterocyclic compound, said ring optionally bearing a radical R, which represent one of the following groups: a hydrogen atom, a linear or branched alkyl radical having from 1 to 6 carbon atoms, a linear or branched alkenyl radical having from 2 to 6 carbon atoms, a linear or branched alkoxy radical having from 1 to 6 carbon atoms, a cyclohexyl radical, an acyl group having from 2 to 6 carbon atoms, or a radical of formula: R1â€”OH R1â€”COOR2 R1â€”CHO R1â€”NO2 R1â€”CN R1â€”C(O)â€”(NR2)2 R1â€”X, or R1â€”CF3 â€ƒwherein, R1 represents a valency bond or a saturated or unsaturated, linear or branched, divalent hydrocarbon radical having from 1 to 6 carbon atoms; the radicals R2, which are identical or different, represent a hydrogen atom or a linear or branched alkyl radical having from 1 to 6 carbon atoms; X symbolizes a halogen atom; n represents the number of substituents on the ring, said process comprising the steps of: a) reacting said aromatic compound with a sulfonating agent, in the presence of a catalytically effective amount of a catalyst which is a mixture of bismuth trihalide and of perfluoroalkanesulfonic acid, whith a molar ratio less than the stoichiometry resulting in the complete exchange of the halide by the sulfonic functional group, to obtain a sulfonated aromatic compound, and b) recovering the sulfonated aromatic compound obtained in step a).