1,2,3-Triazolodiazepine I. Preparation and Benzodiazepine Receptor Binding of 1-Benzyl and 1-Phenethyl-1,2,3-Triazolo[4,5-d][1,4]diazepines

Several new 1,2,3-triazolo[4,5-b][1,4]diazepines were prepared starting from 1-benzyl-1 and 1-phenethyl-4,5-diamino-1,2,3-triazole 2 (Scheme 1), by condensation reactions with β-diketones (Scheme 2), β-ketoesters (Scheme 3), and diethyl malonates (Scheme 4). In the first case we obtained compounds 3 and 4 with basic properties, while the ester function condensations gave cyclic amide derivatives 7, 8, 10, 12 and 13 with acid properties. Some N-methyl derivatives 11, 14 and 15 were obtained from the cyclic amide compounds. Most of compounds were tested for their ability to displace [3H]flunitrazepam from bovine brain membranes but no compound showed benzodiazepine receptor binding affinity.