1 H NMR ( 600 MHz , CDCl 3 ) δ = 7 . 53 ( d , J = 9 . 0 Hz , 2 H ) , 7 . 33 ( d , J = 4 . 2 Hz , 1 H ) , 7 . 21 ( d , J = 9 . 0 Hz , 2 H ) , 6 . 91 ( d , J = 4 . 2 Hz , 1 H ) , 6 . 68 ( t , J = 6 . 0 Hz , 1 H ) , 4 . 90 - 4 . 86 ( m , 1 H ) , 4 . 13 - 4 . 07 ( m , 3 H ) , 3 . 98 - 3 . 95 ( m , 2 H ) , 3 . 93 - 3 . 86 ( m , 2 H ) , 3 . 79 - 3 . 75 ( m , 1 H ) , 3 . 45 ( s , 3 H ) , 1 . 32 - 1 . 24 ( m , 4 H )