Quinazolines and 1,4-benzodiazepines. 82.1 5-Pyrimidyl-and 5-pyrazinylbenzodiazepines.

Analogues of bromazepam [7-bromo-1,3-dihydro-5(2-pyridyl)-2H-1,4-benzodiazepin-2-one, A], which is a clinically useful minor tranquilizer, have been prepared by replacing the 2-pyridyl group at position 5 with 4-pyrimidyl (5), 2-pyrazinyl (8), 2,5-dimethylpyrazin-3-yl (10), and 2-pyrimidyl (12) groups. Low to moderate CNS activities in both mice and cat were found for all the new compounds. For the screening procedures used, the 2-pyrimidyl-substituted derivatives were found to be the most active new analogues although none of the activities exceeded those observed for bromazepam.