Cystic fibrosis is developed through mutation of Cystic Fibrosis Transmembrane conductance Regulator (CFTR), which is one type of chloride channel. An object of the present invention is to provide compounds effective in the treatment of cystic fibrosis that open a chloride channel different from CFTR, which is the cause of the disease, and do not depend on CFTR.Compounds of the present invention are compounds or pharmaceutically acceptable salts thereof that open calcium dependent chloride channels (CaCCs) via G-protein coupled receptor 39 (GPR39) agonism to have strong chloride ion-secretory action, and are represented by the following general formula (I):General formula (I):wherein,X represents a carboxyl group or a tetrazolyl group；Q represents a C1-C3 alkylene group, an oxygen atom, a sulfur atom, etc.；G represents a phenyl group where the phenyl group may have 1 to 3 substituents independently selected from the group consisting of a halogen atom, a cyano group, a C1-C6 alkyl group, etc.；R1 represents a C1-C6 alkyl group, etc.；R2 represents a C1-C6 alkyl group that may have 1 to 3 substituents independently selected from the following group A, or a group selected from the following group B:Group A: a phenyl group and a pyridyl group, wherein the phenyl group and the pyridyl group may have 1 to 3 substituents independently selected from the following group D；Group B: —；OH, —；O-M, —；SH, —；S-M, —；NH2, —；NH-M, and —；N-M2, wherein M is a C1-C6 alkyl group that may have 1 or 2 substituents independently selected from the following group C, or a C3-C6 cycloalkyl group that may have 1 or 2 substituents independently selected from the following group C；Group C: a halogen atom, a cyano group, a phenyl group, a pyridyl group, etc., wherein the phenyl group and the pyridyl group may have 1 to 3 substituents independently selected from the following group D； andGroup D: a halogen atom, a cyano group, a C1-C6 alkyl group, etc.
