| abstract |
A compound of the formula ##STR1## wherein X is hydrogen, halogen or nitro; Ar is phenyl or naphthyridinyl which may optionally be substituted; and either one of Z 1 and Z 2 is hydrogen and the other is lower alkanoyloxy or hydroxy, each of Z 1 and Z 2 is lower alkoxy, or Z 1 and Z 2 combinedly represent hydroxyimino or oxo; and a salt thereof, act on the central nervous system but are weak in adverse effects such as hypnotic and muscle relaxant effects. |