Phosphate esters of gyrase and topoisomerase inhibitors

A compound of the formula (I):

• or a pharmaceutically acceptable salt thereof, wherein
• X is —PO(OH)O—R1, or —PO(O−M+)O—R1;
• M+ is a pharmaceutically acceptable monovalent cation;
• R1 is (C1-C20)-alkyl, (C2-C20)-alkenyl, —(CH2CH2O)nCH3, or R2;
• wherein said alkyl or alkenyl is optionally substituted with R2, —OR9, —N(R9)2, —CN, —C(O)OR9, —C(O)N(R9)2, —N(R9)—C(O)—R9, halogen, —CF3, or —NO2;
• each R2 is independently a 5-6 membered carbocyclic or heterocyclic aliphatic ring system;
• wherein any of said heterocyclic ring systems contains one or more heteroatoms selected from O, N, and N(R9);
• and wherein any of said ring systems optionally contains 1 to 4 substituents independently selected from —OH, C1-C4 alkyl, and —O—(C1-C4)-alkyl;
• each R9 is independently H or a C1-C4 alkyl group;
• and
• n is an integer 1 to 5.