Aromatic sulphonation. Part 76. Sulphonation in sulphuric acid of ω-phenylalkanes containing the NH3+, NMe3+, or NO2 substituent at position 1. Comparison of the side-chain NH3+, NMe3+, NO2, SO3H, and OSO3H substituent effects
The sulphonation of a series of ω-phenylalkanes containing at position 1 the NH3+, NMe3+, and NO2 substituent in concentrated sulphuric acid at 25 °C has been studied, and partial rate factors for the mechanism with H2S2O7 as sulphonating entity are reported. The limiting values of the partial rate factors for para- and meta-substitution are equal to those of the corresponding 1-phenylalkanes, but the limiting value for ortho-substitution is smaller. The variation of the degree of ortho-substitution with the nature of the substituent (NMe3+, NH3+, NO2, OSO3H, SO3H, and Me) is taken to indicate the operation of an inductive effect in addition to the now generally accepted field effect.