1 H NMR ( 400 MHz , DMSO - d 6 ) δ 10 . 39 ( s , 1 H ) , 8 . 06 ( s , 1 H ) , 8 . 00 ( d , J = 2 . 0 Hz , 1 H ) , 7 . 67 ( d , J = 1 . 6 Hz , 1 H ) , 7 . 53 ( d , J = 8 . 8 Hz , 1 H ) , 7 . 29 ( dd , J = 1 . 6 , 8 . 4 Hz , 1 H ) , 6 . 96 ( q , J = 1 . 1 Hz , 1 H ) , 6 . 74 ( d , J = 8 . 0 Hz , 1 H ) , 6 . 61 ( d , J = 2 . 0 Hz , 1 H ) , 6 . 24 ( dd , J = 2 . 4 , 8 . 0 Hz , 1 H ) , 2 . 03 ( s , 3 H ) , 2 . 01 ( s , 3 H ) .