The molecular conformation and supramolecular architecture of cocaethylene [systematic name: ethyl (1R,2R,3S,5S)-3-benzoyloxy-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate], C18H23NO4, have been determined for the first time. Cocaethylene is a narcotic produced in vivo when cocaine and ethanol are administered concomitantly. The intra- and intermolecular features of cocaethylene and its less potent narcotic precursor cocaine are very similar. The only molecular difference is in the conformation of the methyl group of the ethoxycarbonyl group. Similar to cocaine, the carboxylate atoms and the α-C atom are coplanar in cocaethylene, but the methyl C atom of the ethyl group is bent by ca 90° away from this plane in the narcotic reported here. The main supramolecular motif is a one-dimensional chain stabilized by weak C-H...O contacts.
Keywords: benzoylecgonine ester; cocaethylene; cocaine; conformation; crystal structure; narcotic; transesterification.