Indole-fused spirochromenes as potential anti-tubercular agents: design, synthesis and in vitro evaluation

As part of an ongoing effort to develop new anti-tubercular agents, a series of novel indole-fused spirochromene hybrids (7a–l) were efficiently synthesized in excellent yields by the popular ‘Fisher–Indole synthesis’ approach. The structure elucidation of the target compounds was carried out by different spectral techniques including 1H-NMR, 13C-NMR, ESI Mass, and FTIR analysis. Additionally, the proposed structure of 7i was proved by...