1 H - NMR ( 500 MHz , Methylene Chloride - d 2 ) : δ 8 . 8 ( d , - 2 H ) , 8 . 3 ( s , 1 H ) , 8 . 2 ( m , 2 H ) , 8 . 0 ( d , 1 H ) , 7 . 8 ( m , 2 H ) , 7 . 5 ( m , 2 H ) , 7 . 2 ( d , 1 H ) , 6 . 7 ( s , 1 H ) , 3 . 7 ( s , 3 H ) .