1 H NMR ( 400 MHz , DMSO - d 6 ) δ 9 . 77 ( s , 1 H ) , 8 . 46 ( d , J = 9 . 2 Hz , 1 H ) , 7 . 80 ( d , J = 9 . 2 Hz , 1 H ) , 7 . 07 ( d , J = 1 . 2 Hz , 1 H ) , 7 . 01 - 6 . 93 ( m , 2 H ) , 5 . 78 ( dd , J = 10 . 0 , 4 . 4 Hz , 1 H ) , 4 . 35 - 4 . 29 ( m , 1 H ) , 4 . 20 - 4 . 16 ( m , 1 H ) , 4 . 03 ( q , J = 6 . 8 Hz , 2 H ) , 3 . 74 ( s , 3 H ) , 3 . 03 ( s , 3 H ) , 2 . 20 ( s , 3 H ) , 1 . 33 ( t , J = 6 . 8 Hz , 3 H ) . LCMS : [ ( M - H ) ] - = 493 . 1 . ee % = 100 %.