New features in synthesis of talampanel related 2,3-benzodiazepines.

Analogues of talampanel (1), a highly active AMPA antagonist 2,3-benzodiazepine, were synthesized, where the characteristic amino-function was either transposed or sterically shielded. For the key intermediates (hemiketals 6a, b) a new synthetic method of different mechanism was developed. The inactivity of several new compounds indicates the significance of the 4-amino(phenyl) function in BDZs of type 1.