A novel compound of the formula ##STR1## wherein Ar represents a tetracyclic fused heterocyclic group which may be substituted; R.sup.1 represents H or a hydrocarbon group which may be substituted; Y represents an amino acid or nitrogen-containing saturated heterocyclic group which may be substituted, its salt, inhibiting excellent cholinesterase inhibitory activity and monoamine uptake inhibitory activity, thus being useful as therapeutic and/or prophylactic medicaments of senile dementia.