A compound of formula (1), wherein A is C6-10 arylene, etc.； R1a, R1b and R1c are each independently hydrogen atom, halogen atom, C1-4 alkyl, C1-4 alkoxy, etc.； R2 is optionally substituted C6-10 aryl, optionally substituted 5- to 12-membered monocyclic or polycyclic heteroaryl, optionally substituted C7-16 aralkyl, etc.； m is 0, etc.； n is an integer of 0 to 2, or a pharmaceutically acceptable salt thereof is provided.本發明提供一種式(1)所表示之化合物或其藥理學上容許之鹽。[於式中，A係C6-10伸芳基等；R1a、R1b、及R1c分別獨立為氫原子、鹵素原子、C1-4烷基、C1-4烷氧基等；R2係亦可經取代之C6-10芳基、亦可經取代之5員~12員之單環式或多環式雜芳基、亦可經取代之C7-16芳烷基等；m為0等；n為0~2之整數。]
