The iodomethylate of 9-chloro-4-azafluorene is converted to 1H-l-methyl-indeno[1,2-b]pyridine when treated with base. We discuss the structure of compounds containing azalene fragments, which are formed upon heating 9-chloro-4-azafluorene. We discuss some considerations concerning the nomenclature of azulenes with the azafluorene skeleton.
The major method for obtaining azalenes is base treatment of quaternary salts of condensed polynuclear compounds which are classified as CH-acids and contain the pyridinium ring [1]. Continuing investigations of azalenes obtained by this route from quaternary salts of azafluorenes, we turned to synthesis of pseudoazulenes based on 9-chloro-4-azafluorene (I), which is obtained in quantitative yield upon reaction of 4-azafluorenol-9 with thionyl chloride at room temperature. In the IR spectrum of chloride I, there is an absorption band for the stretching vibrations of the C-CI bond at 690 cm -1 . According to data in [2], we can hypothesize that this bond is axial. Partial confirmation of such a hypothesis comes from comparison of the IR spectra of 4-azafluorene and chloride I. In the IR spectrum of compound I, the stretching vibrations of the C(9)-H bond appear at 2955 cm -1, and in the spectrum of 4-azafluorene the bending vibrational band for this bond is shifted toward the 1410 cm-l region, probably due to the axial orientation of the chlorine atom. ~ , 9 "~ Ct