| abstract |
A compound represented by the following general formula (I) or a salt thereof: where the symbols of the formula (I) have the following meanings, respectively: ring A: a 5 or 6 membered hetero ring or a benzene ring; X: C (R4) (R5), O, S or N (R12); R1: C1-C6 alkyl, cycloalkyl, (C1-C6) alkyl, aryl, aryl that may be substituted, heteroaryl that may be substituted, or C1-C6 alkyl substituted with one or more halogens; R2 and R3: are the same or different and each is C1-C6 alkyl or aryl; R4 and R5: they are the same or different and each is a hydrogen atom, C1-C6 alkyl, -O-C1-C6 alkyl, -OH, -alkylene (C1-C6) -OH or -alkylene (C1-C6) -O-C1-C6 alkyl; R6 to R9: they are the same or different and each is a hydrogen atom, C1-C6 alkyl, -O-C1-C6 alkyl, a halogen atom, C1-C6 alkyl substituted with one or more halogens, OH, CN, alkenyl of up to 6 carbon atoms or a heterocyclic group containing nitrogen; R10 and R11: they are the same or different and each is a hydrogen atom or C1-C6 alkyl, and R12: a hydrogen atom or C1-C6 alkyl, provided that R2 and R3 can be taken together with the adjacent carbon atom to form cycloalkyl. |