1 H NMR ( 400 MHz , DMSO - d 6 ) : δ [ ppm ] = 0 . 26 - 0 . 50 ( m , 4 H ) , 1 . 04 - 1 . 13 ( m , 1 H ) , 3 . 41 - 3 . 49 ( m , 1 H ) , 3 . 53 - 3 . 62 ( m , 2 H ) , 4 . 93 ( t , 1 H ) , 7 . 64 ( ddd , 1 H ) , 7 . 88 ( d , 2 H ) , 8 . 16 - 8 . 24 ( m , 3 H ) , 8 . 71 ( dd , 1 H ) , 8 . 74 ( s , 1 H ) , 8 . 93 ( d , 1 H ) , 9 . 52 ( d , 1 H ) .