1 H NMR ( 300 MHz , CDCl 3 ) δ : 8 . 07 ( d , J = 7 . 9 Hz , 1 H ) , 8 . 01 ( d , J = 7 . 9 Hz , 1 H ) , 7 . 64 ( td , J = 7 . 7 , 1 . 3 Hz , 1 H ) , 7 . 43 - 7 . 29 ( m , 4 H ) , 7 . 11 - 7 . 08 ( m , 1 H ) , 7 . 03 - 7 . 00 ( m , 1 H ) , 4 . 18 ( s , 3 H ) .