This invention provides a compound of the formula (I): or a pharmaceutically acceptable salt, 
amide or ester thereof, wherein R1 represents a 
hydrogen atom or a 
halogen atom; R2 represents a 
hydrogen atom, etc.; R3 represents an 
alkyl group having from 1 to 10 carbon atoms; said 
alkyl group of R3 is substituted by at least one 
substituent selected from the group consisting of substituents α; said substituents α is 
aryl, hydroxy, oxo, etc.; said 
aryl having 6 to 10 carbon atoms; said 
aryl is unsubstituted or substituted by at least one 
alkyl group having from 1 to 6 carbon atoms; said heterocyclic and the heterocyclic 
moiety of said heterocycliccarbonyl, both of substituents α, are 5- to 10-membered cyclic groups containing from 1 to 4 heteroatoms selected from the group consisting of 
nitrogen atoms, 
oxygen atoms and 
sulfur atomsThese compounds have 5-HT4 
receptor binding activity, and thus are useful for the treatment of gastroesophageal 
reflux disease, non-ulcer dyspepsia, functional dyspepsia, 
irritable bowel syndrome or the like in mammalian, especially humans. This invention also provides a pharmaceutical composition comprising the above compound.