1 H NMR ( 300 MHz , CDCl 3 ) δ : 8 . 24 - 8 . 21 ( m , 1 H ) , 7 . 75 - 7 . 72 ( m , 1 H ) , 7 . 57 - 7 . 50 ( m , 2 H ) , 6 . 93 ( s , 1 H ) , 4 . 53 ( q , J = 7 . 1 Hz , 2 H ) , 4 . 01 ( s , 3 H ) , 1 . 46 ( t , J = 7 . 1 Hz , 3 H ) .