Synthesis and biological evaluation of 14-alkoxymorphinans. 14.1 14-Ethoxy-5-methyl substituted indolomorphinans with δ opioid receptor selectivity

Abstract The 5-methyl and 14-ethoxy substituted analogues (compounds 2 – 4 ) of the δ opioid receptor antagonist naltrindole showed similar selectivity when compared with the reference drug. Compound 2 was a δ receptor antagonist in the mouse vas deferens preparation (MVD) exhibiting considerably higher selectivity ratios than naltrindole, while compound 4 was found to be a full and potent δ receptor agonist in the MVD.