Antimycobacterial 3-aryl-2H-1,3-benzoxazine-2,4(3H)-diones

A series of 153 derivatives of 3-phenyl-2H-benzoxazine-2,4(3H)-dione substituted in position 6 or 7 on benzoxazine and on the phenyl ring was synthesized. The compounds were evaluated in vitro for antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. The activity of the compounds increases with increasing hydrophobicity and electron-withdrawing properties of the substituents on the phenyl ring, whereas the effect of the substituents on the benzoxazine ring seems to be more complex.