in which R11 is e.g., 4-(pyrrolidin-1-yl)piperidin-1-yl, N-methyl-3-(pyrrolidin-1-yl)propan-1-amino, N1,N1,N3-trimethylpropane-1,3-diamino, N,N-dimethylpiperidin-4-amino, 3-(pyrrolidin-1-ylmethyl)azetidin-1-yl, 3-(pyrrolidin-1-ylmethanon)azetidin-1-yl, or 3-(morpholin-1-ylmethyl)azetidin-1-yl; R13 is, e.g., phenyl optionally substituted with one or more substituents; and R12 and R14 are each independently hydrogen or alkyl. Methods of treatment are also provided.