Sulphonation of phenols

US6936732B2 · kind B2 · utility

Inventors

• Jonathan S. Hill · Chevalleyres, CH
• Bernard Capai · Persan, FR
• Carlo Neri · San Donato Milanese, IT

Key dates

• Filing date: Sep 18, 2002
• Grant date: Aug 30, 2005
• Expiry date: Sep 18, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C303/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

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…