Abstract: The present invention relates to novel benzothiazinone derivatives and their use as antibacterial agents in infectious diseases of mammals (humans and animals) caused by bacteria, especially diseases like tuberculosis (TB) and leprosy caused by mycobacteria. The present invention aims at the generation of new compounds with activity against mycobacteria as potential new tuberculosis drugs to overcome problems concerning resistance and drug intolerance. The solution of the present invention is a compound of formula I wherein R1 to R6 are as defined in the specification.