Nucleophilic Displacement in Polyhalogenoaromatic Compounds. XV. The Azulene-6-yl Substituent

Abstract

6-(p- Fluorophenyl )-4,8-dimethylazulene (1) undergoes methoxydefluorination ( NaOMe ; Me₂SO/MeOH, 9:1, v/v; 323 K) at a rate 1100 times that of fluorobenzene under the same conditions. Substituents (1-NO₂, 1,3-Cl₂) showed effects similar to those in the benzene system. Both the electron-withdrawing effect of the azulen-6-yl substituent and the efficacy of transmission of substituent effects across the polyannular system are unusually large, and reflect the polarizable and dipolar nature of the azulene system.