Compounds represented by the following general formula, pharmaceutically acceptable salts thereof, or hydrates of both exhibit both an excellent enterokinesis-promoting activity and an inhibitory activity against acid secretion and are excellent in safety, thus being useful as preventive or therapeutic agents for gastric or esophageal regurgitation. Formula (1), wherein R?1 and R2¿ are each independently hydrogen or lower alkyl; and A is a substituent selected from the group consisting of 1-azabicyclo[3.2.2]nonyl, 1-azabicyclo[2.2.2]octyl and N-oxides of both.