Dopamine Agonists Related to 3-Allyl-6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-diol. 6-Position Modifications

Article abstract of DOI:10.1021/jm00384a006

The N-allyl derivative (SK and F 85174) of 6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-diol (SK and F 82526) retains the DA-1 agonist potency of the latter compound but unlike the parent also shows substantial DA-2 agonist activity.In a previous study of N-substituted benzazepines these combined agonist effects were shown to be uniquely associated with the N-allyl group.A continuation of this research has examined dependency of combined DA-2/DA-1 agonist activities on 6=position modification with the specific objective of developing an agonist with maximum effectiveness and potency at the DA-2 receptor subtype.DA-2 agonist activity was measured in a rabbit ear artery assay, and DA-1 agonist activity was determined in an adenylate cyclase assay.Replacing chloro with bromo retains the activity pattern and the potency of the chloro compound: replacement with a hydrogen causes a decrease of both DA-1 and DA-2 receptor activating potency.Introduction of a 6-methyl group causes loss of DA-2 agonist activity and reduction in DA-1 agonist potency.Substitution with a 6-fluoro provides the best balance of DA-2 and DA-1 agonist activities; this compound was moderately in both assays.