of the invention resemble those produced by diazepam i e high frequency acitvity is increased mid range frequency is diminished and the activity below 8 hz remains essentially unchanged thus for example administration of the 9 chloro 7 o fluorophenyl 5h dibenz c e azepine or a salt thereof e g its mesylate which are characteristic compounds of the invention when applied to rats at oral doses of 10 30 and 100 mg kg day increase their fr responses with increasing doses but do not suppress the vi responding in said cook davidson test moreover oral doses of 10 and 30 mg kg day increase in the eeg of squirrel monkeys the higher frequencies of the primary and secondary wave but reduce this activity between 8 and 16 hz which changes become evident as early as 30 minutes after treatment and persist throughout the entire recording session but no alterations are apparent below 8 hz moreover the compounds of the invention antagonize metrazole in rats as well as picrotoxin or threshold seizures induced by minimal electro shock in mice therefore they are useful in combatting anxiety problems similar to those treated with diazepam and in the prevention of petit mal seizures in contrast to diazepam said characteristic compounds of the invention appear to be devoid of neurological deficit liability at doses where antianxiety effects are already established finally the compounds of the invention are also valuable intermediates in the preparation of other.