Dibenz[b,f]oxepins of the formula ##STR1## wherein R, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as hereinafter described, are described. The foregoing compounds exhibit strong central depressant and neuroleptic properties, and are useful, for example, in the treatment of acute or chronic schizophrenia and also as tranquilizers.