Substituted benzoxazinorifamycin derivative, process for preparing the same and antibacterial agent containing the same.

摘要

A rifamycin derivative having the formula (I): <CHEM> wherein R<1> is hydrogen atom, methyl group or ethyl group, R<2> is an alkyl group having 1 to 4 carbon atoms, and A is a group having the formula: <CHEM> in which n is an integer of 3 to 5, or a group having the formula: <CHEM> in which R<3> is an alkyl group having 1 to 5 carbon atoms; or a salt thereof. The rifamycin derivative (I) exhibits a strong antibacterial activity against Gram-positive bacteria and acid-fast bacteria, and also exhibits a strong antibacterial activity against tubercle bacilli.