2-Amino acetamide derivatives

Compounds of general formula I, wherein Ar1 and Ar2, which may be the same or different, represent phenyl optionally subsituted by fluorine, and R, R1, R2, R3 and R4 have the meanings given in the description, and pharmaceutically acceptable acid addition salts thereof, are useful as sedatives and in the treatment of epilepsy. The compounds are conveniently prepared by amide-forming reactions, and may be administered in the form of compositions comprising a pharmaceutically acceptable adjuvant, diluent or carrier.