Methods and compositions for treating beta-thalassemia and sickle cell disease

A compound of the formula selected from the group consisting of:

• Formula (VI), Formula (VII), and Formula (VIII):
• or a pharmaceutically acceptable salt thereof,
• wherein:
• R8, R9, R10, R11, R12 and R13 are each independently selected from the group consisting of hydrogen, optionally substituted alkyl, —N(RB)2, and —N(RA)C(O)RA;
• provided that in Formula (VI), R10 is optionally substituted alkyl, —N(RB)2, or —N(RA)C(O)RA.
• R14 is hydrogen, optionally substituted alkyl, optionally substituted alkenyl, or optionally substituted alkynyl;
• each instance of RA is independently selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted alkynyl;
• and
• each instance of RB is independently selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted alkynyl;