New heteroaromatic compounds—IV The nitration and chlorination of 10-methyl-10:9- borazarophenanthrene

10-Methyl- and 10-hydroxy-10:9-borazarophenanthrene have been nitrated with nitric acid in acetic anhydride, and the former compound has been chlorinated with chlorine in acetic acid; the products have been oriented and the proportions of isomers determined quantitatively. The results are shown to be in general agreement with the predictions of MO theory, attack taking place in the 6- and 8-positions. A method for degrading such boron compounds is described, and also the synthesis of 2-, 6-, and 8-chloro-10-methyl-10:9-borazarophenanthrenes as reference compounds. The 6- and 8-amino derivatives of 10-methyl and 10-hydroxy-10:9-borazarophenanthrene have been prepared by reduction of the corresponding nitro derivatives.