Synthesis and Characterization of 1-carboxyphenothiazine Derivatives Bearing Nitrogen Mustard as Promising Class of Antitubercular Agents

A series of 1-carboxyphenothiazines bearing nitrogen mustard was synthesized, characterized, and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. The results showed that compounds 5h, 5i and 5j found most active with percentage inhibition of 96, 91, and 92, respectively, at minimum inhibitory concentration (MIC) of <6.25 μg/mL, among the synthesized compounds. Whereas compounds 5a, 5b, 5c, 5d, 5e, 5f and 5g exhibited considerable antitubercular activity with percentage inhibition of 71, 75, 79, 54, 55, 68, and 66, respectively, at MIC of >6.25 μg/mL. The structures of synthesized compounds were elucidated by various spectroscopic tools like IR, 1H NMR, 13C NMR, mass and elemental analysis.