1 H NMR ( 400 MHz , CDCl 3 ) δ = 7 . 53 ( d , J = 9 Hz , 2 H ) , 7 . 30 ( d , J = 4 Hz , 1 H ) , 7 . 14 ( d , J = 9 Hz , 2 H ) , 6 . 92 ( d , J = 4 Hz , 1 H ) , 6 . 41 ( t , J = 6 Hz , 1 H ) , 4 . 92 - 4 . 84 ( m , 1 H ) , 4 . 13 ( td , J = 8 . 8 , 2 . 8 Hz , 1 H ) , 3 . 96 - 3 . 73 ( m , 11 H ) , 3 . 03 - 2 . 94 ( m , 1 H ) , 2 . 25 - 2 . 15 ( m , 1 H ) , 2 . 04 - 1 . 96 ( m , 1 H )