SULPHONATION OF PHENOLS

摘要

A process for the preparation of sulphonated phenols of general formula (I) where R1 is hydrogen, a C1-C20 alkyl group which is unsubstituted or substituted by halogen, cyano, hydroxyl, C1-C20 alkoxy, C2-C20 alkoxycarbonyl, acyloxy and/or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, R2 is hydrogen, C1-C20 alkyl or benzoyl of general formula (II) where R3 and R4 independently of one another are each hydrogen, halogen, C1-C12 alkyl, C1-C12 alkoxy, C1-C4 haloalkyl, C3-C8 cycloalkyl, C4-C12 cycloalkylalkyl, cyano, hydroxyl, or hydroxyethyl or are each phenoxy, C7-C10 phenylalkyl or phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy and/or halogen, and R5 is hydrogen or the group SO3X where X can be hydrogen, a monovalent metal or a group - N(R6)3, where each of the three radicals R6 can be independently of one another hydrogen, C1-C6 alkyl or C1-C6 hydroxy alkyl, which process comprises reacting a phenol of general formula (III) where R1 and R2 are as defined above, with a halosulphonic acid in a solvent which is a mixture of a C5-C10 aliphatic or cycloaliphatic hydrocarbon and a dialkyl carbonate of general formula (IV) R7-O-CO-O-R8 where R7 and R8 each represent independently a C1-C4 alkyl group.