1 H NMR ( 400 MHz , CDCl 3 ) δ = 7 . 44 ( d , J = 8 . 8 Hz , 2 H ) , 7 . 38 ( d , J = 4 Hz , 1 H ) , 7 . 29 ( d , J = 4 . 0 Hz , 1 H ) , 7 . 04 ( d , J = 4 Hz , 1 H ) , 7 . 02 ( d , J = 8 . 8 Hz , 2 H ) , 6 . 72 ( t , J = 6 . 0 Hz , 1 H ) , 6 . 37 ( d , J = 3 . 6 Hz , 1 H ) , 6 . 33 ( dd , J = 3 . 6 , 2 Hz , 1 H ) , 4 . 90 - 4 . 83 ( m , 1 H ) , 4 . 14 - 4 . 03 ( m , 3 H ) , 3 . 94 - 3 . 84 ( m , 4 H ) , 3 . 75 ( dt , J = 14 . 4 , 6 Hz , 1 H )