Patent ID: 7504393

Claim:
A compound of the formula (I): wherein R 1 is 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 3 is a hydrogen atom or a C 1 -C 6 alkyl group; Arom is an unsubstituted or substituted aryl group, wherein the aryl group is an aromatic hydrocarbon having 5 to 14 carbon atoms; wherein the substituted aryl group is substituted at 1 to 5 positions; and wherein the substituents of the aryl group are independently selected from the group consisting of halogen, C 1 -C 6 alkyl, halogeno C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, C 1 -C 3 alkylenedioxy, C 1 -C 7 alkanoyl, C 2 -C 7 alkyloxycarbonyl, amino, C 1 -C 7 alkanoylamino, hydroxyl, mercapto, cyano, nitro and carboxyl; A is a C 1 -C 6 alkylene group; R a together with R 2 is a C 2 -C 3 alkylene group containing a double bond; E is an oxygen atom, a sulfur atom or a group of the formula: —NR 4 —, wherein R 4 is a hydrogen atom or a C 1 -C 7 alkanoyl group; X 1 and X 2 are either both an oxygen atom or both a sulfur atom, or a pharmacologically acceptable salt or ester thereof.