Meta Toluene Sulphonic Acid and Related Compounds

Meta Toluene Sulphonic Acid by C.F.H. Allen is about the various chemical reactions and compounds related to toluene. Excerpt: «Theoretically toluene should yield three isomeric mono sulphonic acids, in which the entering sulfonic acid group occupies the positions ortho, meta, or para to the methyl group. The action of sulphuric acid on toluene was first investigated by Jaworsky, (Ztschr. Chem. 1,272), who described one toluene sulphonic acid as the resulting compound. In 1869 Engelhardt and Latschinoff (Ibid. 617), heated toluene with sulphuric acid and made and studied the potassium salt of the resulting acid. They obtained two forms, and identified them by fusion with caustic potash which converted them into the ortho and para cresols, showing that sulphonation had taken place in the positions ortho and para to the methyl group.»