Abstract: The synthesis of 10, 9-borazaronaphthalene (I) has been greatly improved and the intermediates have been characterized. The proton nmr spectrum of I has been completely analyzed and its other properties have been studied; I is isomorphous with the isoelectronic naphthalene. Deuteration and bromination of I lead to preferential attack in the 4 (5) position as expected theoretically. revious papers of this series1t4 have described the P ...