1 H NMR ( 300 MHz , CDCl 3 ) δ 8 . 75 ( d . 1 H ) , 8 . 29 ( dd , 1 H ) , 7 . 63 ∼ 7 . 23 ( m , 8 H ) , 7 . 15 ( d , 1 H ) , 6 . 94 ( dd , 1 H ) , 4 . 27 ( t , 2 H ) , 2 . 74 ( brd , 2 H ) , 2 . 41 ( m , 1 H ) , 2 . 22 ( t , 2 H ) , 2 . 19 ( s , 3 H ) , 1 . 89 ∼ 1 . 96 ( m , 4 H ) , 1 . 57 ∼ 1 . 80 ( m , 4 H ) ; MS ( m / e , M +): 532