O=C(Nc1cncc2ccccc12)C1CN(CCC(F)F)Cc2ccc(Cl)cc21
O=C(Nc1cncc2ccccc12)C1CN(CC(F)F)Cc2ccc(Cl)cc21
O=C(Nc1cncc2ccccc12)C1CN(CCC(F)F)C(=O)c2ccc(Cl)cc21
O=C(Nc1cncc2ccccc12)C1CN(CC(F)F)C(=O)c2ccc(Cl)cc21
What if methylamide was replaced by another hydrogen bond donor, less polar but more stable, just an idea, probably not particularly good one (because of increased synthetic difficulty)