1 H NMR ( 300 MHz , CDCl 3 ) δ : 8 . 43 ( d , J = 8 . 4 Hz , 1 H ) , 7 . 67 - 7 . 55 ( m , 7 H ) , 7 . 42 - 7 . 37 ( m , 1 H ) , 7 . 02 ( s , 1 H ) , 4 . 55 ( t , J = 6 . 8 Hz , 2 H ) , 4 . 14 ( s , 3 H ) , 2 . 02 - 1 . 97 ( m , 1 H ) , 1 . 91 - 1 . 85 ( m , 2 H ) , 1 . 09 ( d , J = 6 . 4 Hz , 6 H ) .