Synthesis of the 4 -desmethoxy analogue of RU79115

The synthesis, and biological activity in vitro of the 4 -desmethoxy analogue (3) of RU 79115 (2) is described. Comparison of the biological activity of the two analogues clearly indicated the importance of the 4 -methoxy group in conferring good gyrase B inhibitory activity as well as antibacterial activity.