Patent ID: 8268775

Claim:
A compound of the formula (I): wherein: X and Y independently of one another are OH, O—(C 1 -C 6 )-alkyl, NH 2 or NH—(C 1 -C 6 )-alkyl, or X and Y together form a group —O—; R1 and R2 independently of one another are Cl or H; R3 is H, (C 1 -C 6 )-alkyl, C(═O)—(C 1 -C 6 )-alkyl or (C 1 -C 6 )-alkylene-NH—(C 1 -C 6 )-alkyl; and R4 is H, (C 1 -C 6 )-alkyl or C(═O)—(C 1 -C 6 )-alkyl; or a physiologically acceptable salt of the compound of the formula (I).