1 H NMR ( 300 MHz , CDCl 3 ) δ : 8 . 45 ( s , 1 H ) , 8 . 26 ( d , J = 9 . 2 Hz , 1 H ) , 7 . 73 - 7 . 70 ( m , 1 H ) , 7 . 02 ( s , 1 H ) , 4 . 48 ( q , J = 7 . 2 Hz , 2 H ) , 4 . 03 ( s , 3 H ) , 1 . 46 ( t , J = 7 . 2 Hz , 3 H ) .