Dopamine receptor ligands. Part VII [1]: Novel 3-substituted 5-phenyl-1,2,3,4 5 6-hexahydro-azepino-[4 5-b]indoles as ligands for the dopamine receptors

A number of 5-phenyl-1,2,3,4,5,6-hexahydro-azepino-[4,5-b]indoles 3 were synthesized with different substituents at the azepine-N position (methyl-, allyl-, 2-phenylethyl-, cyclopropylmethyl- and unsubstituted). Furthermore, the indole-N-methylated compound was generated and by using norephedrines and norpseudoephedrines as a chiral pool, 4-methyl-5-phenyl-1,2,3,4,5,6-hexahydro-azepino-[4,5-b]indoles were prepared which contained racemisation at the reacting C-atom. These compounds, as well as the ring-open amino-alcohols, were screened for their affinity to the hD(1)-, hD(5)-, hD(2L)-, and hD(4)-receptors ( please check sentence). They had micromolar affinities for the receptors and showed the highest affinity to the D-1-subtype family. The cyclic compounds possessed the highest affinity, with the cyclopropylmethyl-(3 c) and methyl-substituents (3 e) being the most active of the tested compounds. Based on an intracellular cAMP-assay, the unsubstituted compound (at the azepine-N position) turned out to be an agonist for the D-1- and D-5-subtype family, whereas the substituted compounds showed (partial) agonistic, or even inverse agonistic activity.