## Abstract

The kinetics of the Friedel-Crafts reaction of naphthalene with para-substituted benzenesulphonyl chlorides have been investigated. The rate constants for equations (i) (formation of the sulphonyl cation) and (ii) (sulphone formation) were determined separately. The effect of the para-substituents on k_{1} was XC_{6}H_{4}SO _{2}Cl + AlCl_{3} ⇌ ^{k1}_{k-1} XC _{6}H_{4}SO_{2}^{+}·AlCl_{4} ^{-} (i) XC_{6}H_{4}SO_{2}^{+}· AlCl^{4-} + C_{10}H_{8} →^{k2} XC_{6}H_{4}SO_{2}C_{10}H_{7}· AlCl_{3} + HCl (ii) well expressed by the Yukawa-Tsuno equation, log(k_{1X}/k_{1H}) = ρ_{1}[σ + γ_{1}(Δσ_{R}^{+})] where ρ1 = -2.7 and γ_{1} = 0.4. On the other hand, the effect of the para-substituents on k_{3} (= k_{1}k_{2}/k_{-1}) was expressed by the Brown-Okamoto equation, log(k_{3X}/k_{3H}) = ρ_{3}σ^{+} where ρ_{3} = -2.8. Thus, the electron-donating para-substituents gave the greater reaction rates. We concluded that the sulphonyl cation gives large negative ρ values as a result of its high reactivity, and that its low selectivity for α-attack is due to a steric effect. These kinetic results have been rationalised in terms of bifunctional acid-base catalysis in phenyl-sulphonylation.

Original language | English |
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Pages (from-to) | 777-781 |

Number of pages | 5 |

Journal | Journal of the Chemical Society, Perkin Transactions 2 |

Issue number | 5 |

DOIs | |

Publication status | Published - 1988 |

Externally published | Yes |

## All Science Journal Classification (ASJC) codes

- Chemistry(all)