Patent ID: 7504437

Claim:
A compound of formula (I): wherein R 1 represents a C 1 –C 6 alkyl group, an amino group, a (C 1 –C 6 alkyl) amino group, a di(C 1 –C 6 alkyl) amino group or a nitrogen-containing saturated heterocyclic group; R 2 and R 3 are the same or different and represent a hydrogen atom or a C 1 –C 6 alkyl group; Arom represents an unsubstituted phenyl group or a phenyl group substituted at from 1 to 5 positions by one or more substituents which are the same or different and are from the substituent group α; A represents a C 1 –C 6 alkylene group; R a represents a hydrogen atom, a C 1 –C 6 alkyl group or a C 2 –C 6 alkenyl group; E represents an oxygen atom, a sulfur atom or a group of the formula —NR 4 —, wherein R 4 represents a hydrogen atom or a C 1 –C 7 alkanoyl group; X 1 represents an oxygen atom or a sulfur atom; X 2 is oxygen and is attached at position C4 of the phenyl ring; the substituent group a being selected from the group consisting of a halogen atom, C 1 –C 6 alkyl group, halogeno C 1 –C 6 alkyl group, C 1 –C 6 alkoxy group, C 1 –C 6 alkylthio group, C 1 –C 3 alkylenedioxy group, C 1 –C 7 alkanoyl group, C 2 –C 7 alkyloxycarbonyl group, amino group, C 1 –C 7 alkanoylamino group, hydroxyl group, mercapto group, cyano group, nitro group and carboxyl group; or a pharmacologically acceptable salt or ester thereof.