1 H NMR ( 400 MHz , DMSO - d 6 ) δ [ ppm ] = 1 . 35 ( br d , 2 H ) , 1 . 51 - 1 . 75 ( m , 6 H ) , 3 . 81 ( br s , 1 H ) , 3 . 93 ( m , 4 H ) , 4 . 92 ( d , 1 H ) , 7 . 07 ( t , 1 H ) , 7 . 85 ( d , 1 H ) , 8 . 17 ( s , 1 H ) , 8 . 59 ( s , 1 H ) , 8 . 66 ( dd , 1 H ) , 8 . 70 ( s , 1 H ) , 9 . 36 ( d , 1 H ) , 9 . 70 ( d , 1 H ) .