Patent ID: 8273760

Claim:
A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein: m is an integer selected from 1 and 2; when m is 1, R represents a monovalent group selected from the group consisting of: (vi) —CH 2 CH 2 OH; (vii) —(CH 2 ) 2 —NH—(CH 2 ) 2 —OH; (viii) —(CH 2 ) 3 —N(CH 3 )—(CH 2 ) 3 —NH 2 ; (ix) H; and (x) —CH 3 ; and when m is 2, R is a divalent group represented by the formula —(CH 2 ) n —N(R′) (CH 2 ) n —, wherein R′ is selected from hydrogen and methyl and n is an integer from 2 to 4.