Abstract: Provided is a 2-heteroaryl aminoquinazolinone derivative, which is a compound represented by formula (1): or a pharmaceutically acceptable salt thereof wherein X1 represents CR1 or N, X2 represents CR2 or N, X3 represents CR3 or N, X4 represents CR4 or N, Y represents optionally substituted C1-6 alkyl, an optionally substituted C3-10 alicyclic group, an optionally substituted 4- to 10-membered nitrogen-containing non-aryl heterocycle, optionally substituted C6-10 aryl, or optionally substituted 5- to 10-membered heteroaryl, Z represents optionally substituted 6- to 10-membered heteroaryl, and R1, R2, R3, and R4 each independently represent a hydrogen atom, halogen, cyano, optionally substituted C1-6 alkyl, optionally substituted C1-6 alkoxy, or the like.

Abstract: Disclosed is a compound having a strong affinity to serotonin-4 receptors, which is useful as an enterokinesis-promoting agent or a digestive tract function-improving agent. Specifically, disclosed is a compound represented by Formula (1) or a pharmaceutically acceptable salt thereof. Also specifically disclosed is a pharmaceutical composition containing a compound represented by Formula (1) or a pharmaceutically acceptable salt thereof. [In Formula (1), Ar represents a group represented by Formula (Ar-1) or Formula (Ar-2).