1 H NMR ( 400 MHz , DMSO - d 6 ) δ 12 . 06 ( s , 1 H ) , 9 . 42 ( d , J = 22 . 2 Hz , 1 H ) , 9 . 19 ( s , 1 H ) , 8 . 97 ( s , 1 H ) , 8 . 87 ( d , J = 2 . 3 Hz , 1 H ) , 8 . 80 ( s , 1 H ) , 7 . 89 ( d , J = 4 . 8 Hz , 1 H ) , 7 . 13 ( d , J = 4 . 7 Hz , 1 H ) , 2 . 69 ( s , 3 H ) , 1 . 17 ( d , J = 6 . 3 Hz , 6 H ) , 1 . 12 ( d , J = 1 . 8 Hz , 3 H ) .