1 H NMR ( 400 MHz , DMSO - d 6 ) δ 9 . 70 ( s , 1 H ) , 8 . 44 ( d , J = 8 . 4 Hz , 1 H ) , 7 . 78 - 7 . 81 ( m , 2 H ) , 7 . 57 ( d , J = 6 . 8 Hz , 1 H ) , 7 . 39 ( s , 1 H ) , 5 . 83 ( dd , J = 10 . 4 , 4 . 4 Hz , 1 H ) , 4 . 32 - 4 . 38 ( m , 1 H ) , 4 . 15 - 4 . 20 ( m , 1 H ) , 4 . 05 - 4 . 10 ( m , 2 H ) , 3 . 85 ( s , 3 H ) , 3 . 04 ( s , 3 H ) , 2 . 19 ( s , 3 H ) , 1 . 34 ( t , J = 6 . 8 Hz , 3 H ) . LCMS : [ ( M + 1 ) ] + = 462 . 0 .