Provided is a compound represented by general formula (6) and pharmaceutically acceptable salts thereof. (In the formula, R1 is a hydrogen atom or a C1-6 alkyl group; R2 is a hydrogen atom or a C1-6 alkyl group; R3 is a hydrogen atom, a halogen atom, a C1-6 alkyl group, or a C1-6 haloalkyl group.)
Provided is a compound represented by general formula (6) and pharmaceutically acceptable salts thereof. (In the formula, R
1
is a hydrogen atom or a C
1-6
alkyl group; R
2
is a hydrogen atom or a C
1-6
alkyl group; R
3
is a hydrogen atom, a halogen atom, a C
1-6
alkyl group, or a C
1-6
haloalkyl group.)