Phenothiazine derivatives and uses thereof

A compound of formula (II):

• or a pharmaceutically acceptable salt thereof, wherein
• R1 is selected from the group consisting of hydrogen, —OH, and C1-6alkoxy;
• R2 is C1-6alkyl substituted with one or more substituents each independently selected from the group consisting of —OH, C1-6alkoxy, —C(O)NRaRb, —C(O)Rc, —C(O)ORd, S(O)2C1-6alkyl, and S(O)2NRaRb;
• R3 is hydrogen or C1-6alkyl;
• Ra, Rb, Rc, and Rd are each independently hydrogen or C1-6alkyl;
• n is 1 or 2;
• and
• m is selected from the group consisting of 1, 2, or 3.