Pharmacological activity of novel alkylsulfonylaryl-1-substituted-1,4-benzodiazepine derivatives.

A series of 1-alkylsulfonylaryl-1,4-benzodiazepine derivatives were synthesized and assayed for their pharmacological profile. All the compounds tested exhibited a competitive antagonism of 3H-diazepam binding in cerebellum, cerebrum and submaxillary gland. Compound II (rec. INN tolufazepam) had a Ki of 12.7 nM in cerebrum and 400 nM in the submaxillary gland. It was very potent in preventing convulsions elicited by pentylenetetrazol (ED50 p.o.: 16.5 and ED50 i.v.: 20 mg/kg). This anticonvulsant action was suppressed by previous administration of Ro 15-1788. Compound II was also active in inhibiting suppressive behaviour in the test of Vogel. This compound has a relative low hypnogenic activity as well as a low potency to produce motor incoordination. Our results show that tolufazepam has a potential clinical usefulness.