Heterocyclic organoboron compounds. Part II. Some 2-aryl-benzo- and -naphtho-1,3,2-di-azaborolines and -oxaborolens

Some heterocyclic boron compounds have been prepared by reacting o-phenylenediamine, catechol, naphthalene-2,3-diamine and -2,3-diol with some nitro- and chloro-phenylboronic acids or anhydrides. Comparison of their ultraviolet spectra with those of 2-phenyl-benzo- and -naphtho-1,3,2-diheteroboro-compounds and some analogous benzimidazoles indicates that intramolecular bonding occurs between an o-nitro-group in the 2-phenyl ring and the boron atom of the heterocyclic ring.