1 H NMR ( 400 MHz , DMSO - d 6 ) δ 9 . 68 ( s , 1 H ) , 8 . 49 ( d , J = 8 . 4 Hz , 1 H ) , 7 . 82 ( t , J = 8 . 0 Hz , 1 H ) , 7 . 60 ( d , J = 7 . 2 Hz , 1 H ) , 7 . 28 ( d , J = 8 . 0 Hz , 1 H ) , 7 . 03 ( d , J = 8 . 4 Hz , 1 H ) , 5 . 81 ( dd , J = 10 . 8 , 3 . 6 Hz , 1 H ) , 4 . 32 ( dd , J = 14 . 4 , 3 . 6 Hz , 1 H ) , 4 . 23 - 4 . 15 ( m , 3 H ) , 3 . 76 ( s , 3 H ) , 3 . 10 ( s , 3 H ) , 2 . 34 ( d , J = 6 . 8 Hz , 2 H ) , 2 . 10 - 2 . 07 ( m , 1 H ) , 1 . 16 ( t , J = 7 . 2 Hz , 3 H ) , 0 . 95 ( d , J = 6 . 8 Hz , 6 H ) . LCMS : [ M + H ] + = 504 . 0 .