1 H - NMR ( 400 MHz , CDCl 3 ) : δ = 7 . 94 ∼ 7 . 90 ( m , 8 H ) , 7 . 85 ∼ 7 . 80 ( m , 4 H ) , 7 . 74 ∼ 7 . 71 ( m , 4 H ) , 7 . 58 ∼ 7 . 54 ( m , 4 H ) , 7 . 46 ∼ 7 . 42 ( m , 2 H ) , 7 . 40 ∼ 7 . 35 ( m , 4 H ) , 7 . 29 ∼ 7 . 26 ( m , 4 H ) , 7 . 21 ∼ 7 . 15 ( m , 4 H ) .