Ethanediamine-heterocycle derivatives as inhibitors of protein arginine methyltransferases

A compound of structural Formula I

• or a salt thereof, wherein:
• R1a and R1b are independently chosen from H and CH3;
• R2 is chosen from C1-6alkyl, C3-7cycloalkyl, 4- to 7-membered cycloalkoxy, and (C3-7cycloalkyl)C1-6alkyl, any of which is optionally substituted with one or more R4.
• R3a and R3b are independently chosen from (C1-6alkoxy)C1-6alkyl and (haloC1-6alkoxy)C1-6alkyl;
• each R4 is independently chosen from halo, cyano, hydroxy, C1-6haloalkyl, C1-6alkoxy, and C1-6haloalkoxy, and if R2 is C3-7cycloalkyl, 4- to 7-membered cycloalkoxy, or (C3-7cycloalkyl)C1-6alkyl, then R4 also may be C1-6alkyl;
• and
• provided the compound is not