Synthesis and Evaluation of Functionalized Benzoboroxoles as anti-Tuberculosis Agents

Abstract

Several aminobenzoboroxole derivatives have been prepared starting from o-boronobenzaldehyde. Nitration of the benzoboroxole followed by Pd-C mediated hydrogenation provided 6-aminobenzoboroxole. Using this amine as a common intermediate, numerous structurally interesting benzoboroxoles have been prepared employing aromatic bromination, N-alkylation, reductive amination, and N-amidation. 3-Substituted functionalized benzoboroxoles have been synthesized via Baylis-Hillman reaction followed by nitration and reduction which provided highly functionalized amino benzoboroxoles. These derivatives have been evaluated for their anti-tubercular activity on mycobacterium tuberculosis H37Rv using 7H9 and GAST protocols. Based on these studies, a potent benzoboroxole analog has also been identified for further development.