abstract |
(57) Abstract: The present invention provides a compound of formula (I) (wherein, n represents an integer of 0 ≦ n ≦ 3; m represents an integer of 0 ≦ m ≦ 6; R 3 and R 4 , Together form a phenyl ring; B represents a heteroaryl group; R 1 and R 2 represent a hydrogen atom or a group as defined herein). |