Patent ID: 8354400

Claim:
A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein one of R 5 , R 6 , or R 7 is a group of formula (a): and when R 5 is (a), R 6 and R 7 are both H; when R 6 is (a), R 5 and R 7 are both H; and when R 7 is (a), R 5 and R 6 are both H; i and j are the same and are 0, 1, 2, 3, or 4; R 1 and R 4 are the same and selected from the group consisting of H, CH 3 , and CH 2 CH 3 ; R 2 is CH 3 and R 3 is selected from the group consisting of (CH 2 ) h N(CH 3 ) 2 and (CH 2 ) 2 O(CH 2 ) 2 O(CH 2 ) 2 N(CH 3 ) 2 , wherein h is 2, 3, or 4; or R 2 and R 3 are the same and selected from the group consisting of: (CH 2 ) k CH 3 , wherein k is 0, 1 or 2, (CH 2 ) m N(CH 2 CH 3 ) 2 , wherein m is 2 or 3, (CH 2 ) n N(CH 3 ) 2 , wherein n is 2, 3 or 4, (CH 2 ) p O(CH 2 ) q N(CH 3 ) 2 , wherein p and q are the same and are 2 or 3; a group of formula (b): wherein u is 0 or 1; or a group of formula (c): wherein v is 0 or 1, Z is N or CH, and X is O or NCH 3 ; or R 1 —N—R 2 and R 3 —N—R 4 are the same and selected from the group consisting of: a group of formula (d): and a group of formula (e): wherein r is 1, 2, or 3, Y is CH or N, R 8 is H, CH 3 , CH(CH 3 ) 2 , N(CH 3 ) 2 , CH 2 OCH 3 , or a group of formula (f): wherein t is 0 or 1, and R 9 is H, CH 2 OCH 3 , or a group of formula (f).