1 H NMR ( 400 MHz , DMSO - d 6 ) δ 9 . 76 ( s , 1 H ) , 8 . 44 - 8 . 41 ( m , 1 H ) , 7 . 67 ( t , J = 9 . 2 Hz , 1 H ) , 7 . 25 - 6 . 88 ( m , 4 H ) , 5 . 83 ( dd , J = 10 . 4 , 4 . 4 Hz , 1 H ) , 4 . 34 - 4 . 19 ( m , 2 H ) , 4 . 12 ( q , J = 7 . 2 Hz , 2 H ) , 3 . 06 ( s , 3 H ) , 2 . 17 ( s , 3 H ) , 1 . 35 ( t , J = 7 . 2 Hz , 3 H ) . LCMS : [ M + H ] + = 514 . 9 .