Patent ID: 7557215

Claim:
An anthraquinone compound of the general formula I or a salt thereof in which R 1 is at the 4 position and is selected from the group consisting of H, —NHR 0 N (R 5 ) 2 in which R 0 is a C 1-12 alkanediyl and each R 5 is H or optionally substituted C 1-4 alkyl, and a group of formula II in which at least one of R 6 , R 7 and R 8 is selected from X 2 , and X 2 substituted C 1-4 alkyl and any others are H or C 1-4 alkyl; R 9 is selected from H, C 1-4 alkyl, X 2 and X 2 substituted C 1-4 alkyl; m is 0 or 1; n is 1 or 2; R 2 is at the 1 position and is selected from H, —NHR 0 N (R 5 ) 2 in which R 0 is a C 1-12 alkanediyl and each R 5 is H or optionally substituted C 1-4 alkyl, and a group of formula II in which at least one of R 6 , R 7 and R 8 is selected from X 2 , and X 2 substituted C 1-4 alkyl and any others are H or C 1-4 alkyl; R 9 is selected from H, C 1-4 alkyl, X 2 and X 2 substituted C 1-4 alkyl; m is 0 or 1; n is 1 or 2; R 3 is at the 5 position and is H or OH; R 4 is at the 8 position and is H or OH; X 2 is a halogen atom, a hydroxyl group, an aryloxy group or an acyloxy group or another nucleofugal leaving group; provided that at least one of R 1 or R 2 is a group of formula II.