1,2,3-Triazolo[1,5-a][1,4]- and 1,2,3-Triazolo[1,5-a][1,5]benzodiazepine derivatives: synthesis and benzodiazepine receptor binding.

This paper reports the synthesis of new 1,2,3-triazolo[1,4]benzodiazepine and 1,2,3-triazolo[1,5]benzodiazepine derivatives and their evaluation toward benzodiazepine receptors, Receptor affinity gradually and remarkably increases by moving the nitrogen atom of the central ring from position 3 through 4 to position 5, to give the most effective compound 6a (K-i = 150 nM). N-methylation of the diazepine ring (7a) lowers receptorial binding. Introduction of a chlorine atom on the benzene ring doubles the K-i value (6b) which remains unaltered by the N-methylation (7b). (C) 1998 Elsevier Science S.A. All rights reserved.