Patent ID: 8309575

Claim:
A method of studying the response of a biological system or sample comprising a 5-HT 4 receptor to a selective 5-HT 4 receptor agonist, the method comprising: (a) contacting the biological system or sample with a compound of formula (I): wherein: R 1 is hydrogen, halo, hydroxy, C 1-4 alkyl, or C 1-4 alkoxy; R 2 is C 3-4 alkyl, or C 3-6 cycloalkyl; R 3 is hydrogen or C 1-3 alkyl; R 4 is —S(O) 2 R 6 or —C(O)R 7 ; R 5 is hydrogen, C 1-3 alkyl, C 2-3 alkyl substituted with —OH or C 1-3 alkoxy, or —CH 2 -pyridyl; R 6 is C 1-3 alkyl; or, R 5 and R 6 taken together form C 3-4 alkylenyl; and R 7 is hydrogen, C 1-3 alkyl, or pyridyl; or a pharmaceutically-acceptable salt or stereoisomer thereof; and (b) determining the effect caused by the compound on the biological system or sample.