The 9-NH group--an essential structure element for the high affinity of beta-carboline esters to the benzodiazepine receptor

The 9-NH group, an essential structural fragment for high affinity of β-carbolinesters to the benzodiazepine receptor The synthesis of the compounds 1a – 6 , which in part are new, is described. By means of the in vitro binding it is shown, that the 9–NH group is a necessary condition for a high affinity to the benzodiazepine receptor.