QUINAZOLINE DERIVATIVE

摘要

A compound represented by the formula (I): ring A (wherein R<1> represents lower alkyl, etc.; R<2> and R<3> are the same or different and each represents hydrogen, etc.; R<4> represents, e.g., a group represented by the formula (II): X1 represents NH, O, or S; Y represents N or C; Ar represents, e.g., a divalent group formed by removing two hydrogen atoms from aryl; and ring A represents a 5- or 6-membered heteroaryl, etc.) or a pharmaceutically acceptable salt of the compound. They have antagonistic activity against a histamine H3 receptor and inverse antagonistic activity against a histamine H3receptor and are useful in the prevention or treatment of metabolic system diseases, circulatory system diseases, or nervous system diseases.