Abstract On the basis of a preliminary study of the antimycobacterial activity of thiobenzanilides, a group of 4'-isopropyl-and 4'-butylthiobenzanilides have been synthesized and tested against Mycobacterium tuberculosis, Mycobacterium kansasii, Mycobacterium avium and Mycobacterium fortuitum. The effect of the substituents on minimum inhibitory concentrations was calculated by the Free-Wilson method. The ...