Abstract: An improved process for sulphonation of organic compounds, notably hydroxybenzene and alkylbenzene compounds, comprises reacting them with sulphuric acid or oleum in the presence of an organic solvent, notably an n-alkane or a cycloalkane. Also described is a method of extracting an alkylbenzene sulphonic compound from a sulphonation reaction mixture, using an alkylbenzene extractant of lower molecular weight, for example cumene. Some of the alkylbenzene sulphonic compounds are novel.