The purpose of the present invention is to provide an [alpha], [beta]-unsaturated amide compound or a pharmaceutically acceptable salt thereof or the like, which has anti-cancer activity or the like. An [alpha], [beta]-unsaturated amide compound represented by formula (I) and a pharmaceutically acceptable salt thereof or the like have anti-cancer activity or the like. (In the formula, A represents an optionally substituted heterocyclic diyl group； R1 represents a hydrogen atom or an optionally substituted lower alkyl group； R2 represents an optionally substituted aryl group, an optionally substituted cycloalkyl group, an optionally substituted aliphatic heterocyclic group or an optionally substituted aromatic heterocyclic group； X represents -O-, -S-, -SO2-, -NRX1- (wherein RX1 represents a hydrogen atom or a lower alkyl group), -CHRX2- (wherein RX2 represents a hydrogen atom or a hydroxy group), -CH=CH-, -CO- or -NH-CO-； and n1 and n2 may be the same or different, and each represents 0 or 1).本發明之目的在於提供一種具有抗癌活性等之α、β不飽和醯胺化合物或其藥學上容許之鹽等。下述式(I)所示之α、β不飽和醯胺化合物或其藥學上容許之鹽等具有抗癌活性等：[式中，A表示可具有取代基之雜環二基， R1表示氫原子或可具有取代基之低級烷基， R2表示可具有取代基之芳基、可具有取代基之環烷基、可具有取代基之脂肪族雜環基或可具有取代基之芳香族雜環基， X表示-O-、-S-、-SO2-、-NRX1-(式中，RX1表示氫原子或低級烷基)、-CHRX2-(式中，RX2表示氫原子或羥基)、-CH=CH-、-CO-或-NH-CO-， n1及n2為相同或相異，分別表示0或1]。
