A compound of the formula ##STR1## wherein n = 2 or 3; R.sub.1 is a C.sub.3 -C.sub.20 alkyl or arylalkyl; R.sub.2 is loweralkyl or phenyl; and R.sub.3 is H or replaces the hydrogens in (CH.sub.2).sub.n with CH.sub.3 ; and m is 1, 2 or 4. These compounds exhibit central nervous system activity and are useful as antidepressants.