1 H NMR ( 400 MHz , DMSO - d 6 ) : δ 8 . 07 ( s , 1 H ) , 7 . 17 ( s , 1 H ) , 4 . 29 - 4 . 32 ( m , 1 H ) , 4 . 13 ( q , J = 7 . 2 Hz , 2 H ) , 3 . 82 ( s , 3 H ) , 3 . 37 - 3 . 46 ( m , 2 H ) , 3 . 05 ( s , 3 H ) , 1 . 36 ( t , J = 7 . 2 Hz , 3 H ) .