1 H - NMR : ( 300 MHz , DMSO - d 6 ) δ 11 . 43 ( s , 1 H ) , 9 . 88 ( s , 1 H ) , 8 . 22 ( s , 1 H ) , 7 . 41 ( dd , 1 H , J = 2 . 25 Hz , 2 . 28 Hz ) , 7 . 29 ( m , 2 H , J = 5 . 64 Hz , 7 . 35 Hz , 7 . 53 Hz ) , 6 . 07 ( s , 1 H ) , 4 . 18 ( d , 2 H , J = 13 . 35 Hz ) , 3 . 62 ( s , 3 H ) , 3 . 02 ( t , 3 H , J = 9 . 39 Hz ) , 2 . 67 ( m , 1 H ) , 2 . 41 ( s , 3 H ) , 2 . 24 ( s , 3 H ) , 1 . 94 ( d , 2 H , J = 12 . 63 Hz ) , 1 . 53 ( m , 2 H ) .