Patent ID: 8445509

Claim:
A compound represented by the formula wherein R 1a and R 2a are the same or different and each is (1) a hydrogen atom, (2) a halogen atom, (3) a group bonded via a carbon atom, (4) a group bonded via a nitrogen atom, (5) a group bonded via an oxygen atom, or (6) a group bonded via a sulfur atom; W a is O or S; X a is CR 3a (R 3a is a hydrogen atom, a halogen atom or C 1-6 alkyl), or N; Y a is CR 4a (R 4a is a hydrogen atom, a halogen atom or C 1-6 alkyl), or N; R 5a is (1) C 3-6 cycloalkyl optionally having one C 6-10 aryl-aminocarbonyl optionally having 1 to 3 substituents selected from a halogen atom and C 1-6 alkyl, (2) C 1-6 alkyl-carbonylamino optionally having one C 6-10 aryl, (3) C 1-6 alkoxy optionally having one C 6-10 aryl, or (4) a nitrogen-containing heterocyclic group or an N-oxide thereof optionally having 1 to 4 substituents selected from (a) C 6-10 aryl optionally having 1 to 3 substituents selected from a halogen atom and C 1-6 alkyl, (b) C 1-6 alkyl optionally having 1 to 3 halogen atoms, and (c) oxo; R 6a is a hydrogen atom; R 7a is a hydrogen atom, a halogen atom or C 1-6 alkyl; R 8a is a hydrogen atom, a halogen atom or C 1-6 alkyl, or a salt thereof.