1 H NMR ( 400 MHz , DMSO - d 6 ) δ [ ppm ] = 1 . 40 - 1 . 53 ( m , 2 H ) , 1 . 66 ( br s , 1 H ) , 1 . 72 - 1 . 89 ( m , 1 H ) , 1 . 92 - 2 . 11 ( m , 2 H ) , 3 . 69 - 3 . 80 ( m , 1 H ) , 3 . 96 ( br s , 1 H ) , 5 . 77 ( d , 1 H ) , 7 . 56 - 7 . 61 ( m , 2 H ) , 7 . 63 ( dd , 1 H ) , 7 . 98 - 8 . 02 ( m , 2 H ) , 8 . 14 - 8 . 18 ( m , 1 H ) , 8 . 67 ( s , 1 H ) , 8 . 70 ( dd , 1 H ) , 8 . 91 ( d , 1 H ) , 9 . 51 ( d , 1 H ) .