Synthesis, molecular structure, and properties of 2-(2-hydroxyphenyl)-1- azaazulene

We herein report the synthesis of 2-(2-methoxyphenyl)-1-azaazulene (8) by a Suzuki-Miyaura cross-coupling reaction between 2-chloro-1-azaazulene and 2-methoxyphenylboronic acid and also by the condensation of tropone and the ylide derived from 1-(o-methoxyphenacyl)pyridinium iodide. Demethylation of 8 afforded the title compound 6. X-ray crystallographic analysis of 6 provided evidence for an intramolecular hydrogen bond between the phenolic hydrogen atom and the nitrogen atom of the azaazulenyl ring and also revealed its coplanar ring system. We also report the acidity, basicity, and absorption and emission behavior of 6.