1 H NMR ( 300 MHz , DMSO - d 6 ) : δ 7 . 52 ( d , J = 8 . 1 Hz , 1 H ) , 7 . 35 ( d , J = 8 . 4 Hz , 1 H ) , 6 . 80 ( s , 2 H ) , 5 . 55 ( s , 1 H ) , 4 . 40 ( q , J = 6 . 9 Hz , 2 H ) , 3 . 83 ( s , 3 H ) , 3 . 00 ( s , 3 H ) , 1 . 34 ( t , J = 6 . 9 Hz , 3 H ) .