1 H NMR ( 400 MHz , MeOD - d 4 ) δ 8 . 79 ( s , 1 H ) , 8 . 39 ( s , 1 H ) , 8 . 02 ( d , J = 8 . 6 Hz , 1 H ) , 7 . 77 ( t , J = 7 . 7 Hz , 1 H ) , 7 . 66 - 7 . 58 ( m , 6 H ) , 7 . 40 ( t , J = 7 . 9 Hz , 1 H ) , 7 . 34 ( d , J = 8 . 5 Hz , 2 H ) , 7 . 25 ( q , J = 8 . 6 Hz , 4 H ) , 6 . 87 ( d , J = 8 . 7 Hz , 2 H ) , 3 . 15 ( s , 6 H ) , 3 . 04 ( s , 6 H ) , 2 . 55 ( s , 3 H ) ;