1 H NMR ( 300 MHz , CDCl 3 ) δ 8 . 18 ( d , J = 8 . 5 Hz , 1 H ) , 7 . 73 ( d , J = 8 . 5 Hz , 1 H ) , 3 . 63 - 3 . 51 ( m , 2 H ) , 1 . 96 - 1 . 79 ( m , 2 H ) , 1 . 55 - 1 . 40 ( m , 2 H ) , 1 . 35 - 1 . 29 ( m , 4 H ) , 0 . 95 - 0 . 82 ( m , 3 H ) ;