1 H NMR ( 300 MHz , CDCl 3 ) δ 8 . 02 ( s , 1 H ) , 7 . 84 ( d , 2 H , J = 8 . 7 Hz ) , 7 . 78 ( d , 2 H , J = 8 . 7 Hz ) , 7 . 65 ( d , 2 H , J = 8 . 5 Hz ) , 7 . 41 ( m , 2 H ) , 7 . 22 ( t , 1 H , J = 7 . 4 Hz ) , 7 . 07 - 7 . 04 ( m , 4 H ) .