Alpha-and beta-halomorphides: stereochemistry, analgesic potency, toxicity, and interaction with narcotic receptors...

The configuration of the halogen on the C-ring of several alpha- and beta-halomorphides was determined by NMR. The analgesic potencies of these halomorphides and their interactions with narcotic receptors in a rat brain homogenate were measured, as was the toxicity of the alpha- and beta-chloromorphides. The halomorphides were examined as possible irreversible binders to the narcotic receptor.