1 H NMR ( 400 MHz , DMSO - d 6 ) δ [ ppm ] = 1 . 50 - 1 . 67 ( m , 3 H ) , 1 . 71 - 1 . 89 ( m , 2 H ) , 1 . 92 - 2 . 04 ( m , 1 H ) , 3 . 93 ( s , 3 H ) , 4 . 02 - 4 . 15 ( m , 2 H ) , 5 . 05 ( br s , 1 H ) , 7 . 56 - 7 . 64 ( m , 2 H ) , 8 . 07 - 8 . 13 ( m , 3 H ) , 8 . 55 - 8 . 58 ( m , 1 H ) , 8 . 60 ( s , 1 H ) , 9 . 77 ( d , 1 H ) .