Aromatic sulphonation. Part XLI. Sulphonation of 3-phenylpropane-1-sulphonic acid in sulphuric acid

Abstract

The kinetics of sulphonation of 3-phenylpropane-1-sulphonic acid in 77·8–94·8% H₂SO₄ at 25° have been studied. The results are discussed in terms of sulphonation of the un-ionized sulphonic acid and its conjugate base, the sulphonate anion, by the entities H₂S₂O₇ and H₃SO₄⁺. The partial rate factors for the [CH₂]₃SO₃H substituent for sulphonation with H₂S₂O₇ are f_p= 10·1 ± 1·1, f_m= 0·22 ± 0·13, and f_o= 0·39 ± 0·14.