5-Azidoepibatidine: an exceptionally potent photoaffinity ligand for neuronal alpha 4 beta 2 and alpha 7 nicotinic acetylcholine receptors.

Racemic 5-azidoepibatidine [(+/-)-1] was synthesized via 5-aminoepibatidine as a candidate photoaffinity ligand with exceptionally high affinity at the mammalian neuronal nicotinic receptors (K(i) values of 0.027 nM for alpha 4 beta 2 and 9.7 nM for alpha 7) and excellent photoreactivity.