< Topic > The chemical compounds which are effective to the prevention, remedy or improvement of the disease whose toronbopoechinreseputa activation action is effective are offered.Solutions Formula (i) (R1 in formula, R2, R3, R4 is defined in context) with tautomerization isomer of chemical compound and the said chemical compound which are displayed, the professional drug or the salt which that medicine can be allowed or those solvent dishes dressed with sauce.< Conversion 1 >【課題】トロンボポエチンレセプター活性化作用が有効な疾患の予防、治療又は改善に有効な化合物類を提供する。【解決手段】式(I)(式中のR1、R2、R3、R4は、本文中に定義される)で表わされる化合物、該化合物の互変異性体、プロドラッグ若しくはその医薬的に許容され得る塩又はそれらの溶媒和物。【化1】
