Bisphosphonamidate prodrugs and uses thereof

A compound having the formula

• wherein
• X is a leaving group;
• R1 and R2 are the same or different and each is selected from the group consisting of H, halogen, alkyl, alkenyl, haloalkyl, aralkyl, heteroaralkyl, aryloxy, arylthio, aminoalkyl, hydroxylalkyl, alkoxyalkyl, hydroxyl, amino, alkylamino, arylamino, heteroarylamino, alkylaminoalkyl, arylaminoalkyl, heteroarylaminoalkyl, alkoxy, alkoxyalkyl, alkylthio, O-acyl, N-acyl, and S-acyl, or
• R1 is H, halogen, alkyl, alkenyl, haloalkyl, aralkyl, heteroaralkyl, aryloxy, arylthio, aminoalkyl, hydroxylalkyl, or alkoxyalkyl and R2 is H, halogen, alkyl, alkenyl, haloalkyl, hydroxyl, amino, alkoxy, alkylthio, O-acyl, N-acyl, or S-acyl;
• each R3 is the same or different and is alkyl, hydroxyl, or alkoxy;
• each R4 is the same or different and is alkyl, aralkyl, heteroaralkyl or
• where m is 1, 2, 3, 4, 5, or 6;
• one of R5a and R5b is H or R7 and the other of R5a and R5b is H, halogen, nitro, alkyl, haloalkyl, hydroxyl, amino, alkoxy, alkylthio, O-acyl, N-acyl, S-acyl, or N—O-acyl;
• and R7 represents one or more substituents up to the total number of available positions and is hydrogen, halogen, alkyl, haloalkyl, or alkoxy;
• A is —O—, —S—, —N(R8)—, —C═C—;
• —C═N—, or N═C and R8 is hydrogen or alkyl;
• or both R4 taken together are
• wherein R7 and A are defined as above and one of R6a and R6b is H or R7 and the other of R6a and R6b is nitro, O-acyl, N-acyl, N—O-acyl or —N═N—R9 where R9 is alkyl or aryl;
• and pharmaceutically acceptable salts thereof.