2,3‐Substituted 2‐Azanorbornanes as Polar β‐Turn Mimetics.

The design and synthesis of N -(3-indolylmethyl)-3-benzyl-2-azabicyclo[2.2.1]heptane-2-carboxamide ( 3 ) as a conformationally constrained non-peptide β-turn mimetic is described. Compound 3 is shown to mimic the Trp and Phe side chain conformation and the overall dipole moment of MEN10627 ( 2 ), a cyclic hexapeptide with a high NK-2 affinity. The tachykinin receptor affinities of 3 are evaluated and compared to those of MEN10627 and previously reported Trp-Phe mimetic 1 .