Patent ID: 7067481

Claim:
A compound of formula I: or a pharmaceutically-acceptable salt thereof, wherein: each of X 1 and X 2 is independently hydrogen or chloro; W is selected from N and CCl; R 2 is hydrogen or C 1-6 alkyl; one of R 4 and R 5 is hydroxy and the other is hydrogen; each of R 6 and R 7 is independently hydrogen or methyl; R 8 is hydrogen or a group of the formula: R 9 is selected from hydrogen, C 1-6 alkyl, and C 3-6 cycloalkyl, where alkyl and cycloalkyl may be substituted with —COOH or 1 to 3 fluorine atoms; each R 3 is independently selected from C 1-6 alkyl, —OR, halo, —SR, —S(O)R, —S(O) 2 R, and —S(O) 2 OR, where each R is independently C 1-6 alkyl, which may be substituted with COOH or 1 to 3 fluorine atoms; n is 0, 1, 2 or 3; x is 0, 1 or 2; y is 0, 1 or 2; R a is —Y—R″—, where R″ is selected from C 1-12 alkylene, C 2-12 alkenylene, C 2-12 alkynylene, C 3-6 cycloalkylene, C 6-10 arylene, C 2-9 heteroarylene, C 3-6 heterocycle, and combinations thereof, and is optionally substituted with 1 or 2 groups selected from Z, where Z consists of —OR′, —SR′, —F, —Cl, —N(R′) 2 , —OC(O)R′, —C(O)OR′, —NHC(O)R′, —C(O)N(R′) 2 , —CF 3 , and —OCF 3 , and side chains of naturally occurring amino acids, where each R′ is independently hydrogen or C 1-4 alkyl; and R″ contains at most 20 non-hydrogen atoms; Y, which links R″ to the pyridinium ring at a meta or para position, is selected from a direct bond, NR′, O, S, C(O), NR′C(O), and C(O)NR′, precluding direct bonds between heteroatoms in Y and R″; each R b and R d is independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl; each R c is independently —Y′—R″—Y′—, where each Y′ is independently selected from a direct bond, O, and NR′, precluding direct bonds between heteroatoms in Y′ and R″; and each R e is independently selected from R″.