1 H NMR ( 400 MHz , DMSO - d 6 ) : δ [ ppm ] = 0 . 25 - 0 . 50 ( m , 4 H ) , 1 . 03 - 1 . 11 ( m , 1 H ) , 3 . 40 - 3 . 48 ( m , 1 H ) , 3 . 63 ( ddd , 2 H ) , 4 . 93 ( t , 1 H ) , 7 . 56 - 7 . 61 ( m , 2 H ) , 7 . 61 - 7 . 65 ( m , 1 H ) , 7 . 99 - 8 . 03 ( m , 2 H ) , 8 . 17 ( ddd , 1 H ) , 8 . 68 ( s , 1 H ) , 8 . 70 ( dd , 1 H ) , 8 . 91 ( d , 1 H ) , 9 . 53 ( d , 1 H ) .