By the reaction of aromatic nitro compounds and α-picoline, in the presence of sulfur, p-phenoxyanilide, p-allyloxyanilide, and p-isopropoxyanilide of thiopicolinic acid and their corresponding benzothiazole derivatives were obtained. In the case of aromatic primary amines, only the p-anisidide and p-phenetidide of thiopicolinic acid were obtained and not their corresponding benzothiazole derivatives that they were submitted separately to oxidative cyclization to the benzothiazoles. It has experimentally been proved, through the use of nitrobenzene, that the aromatic nitro radical acts as an oxidative cyclization agent. Thiopicolinic acid p-anisidide was found to be effective in antibacterial tests in the following dilutions: Tubercle bacilli (judged after 4 weeks, in Kirchner medium) 320, 000; Staph. aureus, <10, 000; Esch. coli <10, 000; S. dysenteriae (Shiga), <10, 000; Vibrio cholerae <10, 000.