1 H NMR ( 400 MHz , MeOD ) δ 7 . 55 ( d , J = 1 . 2 Hz , 1 H ) , 7 . 33 ( d , J = 8 . 4 Hz , 1 H ) , 7 . 22 ( dd , J = 1 . 6 , 8 . 4 Hz , 1 H ) , 6 . 88 - 6 . 94 ( m , 1 H ) , 6 . 61 ( s , 1 H ) , 6 . 44 ( ddd , J = 2 . 4 , 8 . 4 , 8 . 4 Hz , 1 H ) , 6 . 36 ( dd , J = 1 . 6 , 8 . 0 Hz , 1 H ) , 6 . 28 ( ddd , J = 2 . 0 , 2 . 0 , 10 . 8 Hz , 1 H ) , 4 . 57 ( s , 2 H ) .