The present invention relates to the compound represented by the following formula (1) [in the formula, X represents an oxygen atom, an imino group, a sulfur atom, sulfinyl, or sulfonyl, R1, R2 and R3 each independently represent a hydrogen atom or a C1-C6 alkyl group, R4 represents a hydrogen atom, a C1-C6 alkyl group, or an arylalkyl group, and R5 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heteroaryl group]. By having an excellent activity of promoting EPO production, the compound is useful as a pharmaceutical agent.本發明係關於一種下述通式(1)所表示之化合物,[上述式中,X表示氧原子、亞胺基、硫原子、亞磺醯基或磺醯基,R1、R2及R3分別獨立表示氫原子或C1-C6之烷基,R4表示氫原子、C1-C6之烷基或芳烷基,R5表示烷基、烯基、炔基、芳基、雜芳基]。該化合物具有優異之EPO產生促進作用,作為藥物有用。
