CNC(=O)C1(N2CC3(CCN(c4cncc5ccccc45)C3=O)c3cc(Cl)ccc3C2=O)CC1
CNC(=O)C1(N2CC3(CCN(c4cncc5cc(S(C)(=O)=O)ccc45)C3=O)c3cc(Cl)ccc3C2=O)CC1
CNC(=O)C1(N2CC3(CCN(c4cncc5ccccc45)C3=O)c3cc(Cl)ccc3S2(=O)=O)CC1
combined spiro ring system with cyclopropyl glycine and lactam for maximum stability and potency.