1 H NMR ( 400 MHz , DMSO - d 6 ) δ 9 . 78 ( s , 1 H ) , 8 . 44 - 8 . 46 ( m , 1 H ) , 7 . 69 ( t , J = 8 . 8 Hz , 1 H ) , 7 . 28 ( d , J = 8 . 0 Hz , 1 H ) , 7 . 06 ( d , J = 8 . 0 Hz , 1 H ) , 5 . 80 ( d , J = 8 . 0 Hz , 1 H ) , 4 . 12 - 4 . 35 ( m , 4 H ) , 3 . 77 ( s , 3 H ) , 3 . 10 ( s , 3 H ) , 2 . 17 ( s , 3 H ) , 1 . 20 ( t , J = 6 . 8 Hz , 3 H ) . LCMS : [ ( M + 1 ) ] + = 480 . 0