1 H NMR ( 400 MHz , DMSO - d 6 ) δ 11 . 52 ( s , 1 H ) , 6 . 90 - 6 . 92 ( m , 1 H ) , 6 . 77 ( d , J = 7 . 2 Hz , 1 H ) , 6 . 06 ( dd , J = 14 . 0 , 6 . 8 Hz , 1 H ) , 3 . 91 ( q , J = 6 . 8 Hz , 2 H ) , 1 . 30 ( t , J = 6 . 8 Hz , 3 H ) .