1 H NMR ( 300 MHz , DMSO - d 6 ) : δ 10 . 51 ( s , 1 H ) , 8 . 88 ( d , J = 4 . 8 Hz , 1 H ) , 7 . 67 ( s , 1 H ) , 7 . 09 ( s , 1 H ) , 6 . 92 - 7 . 00 ( m , 2 H ) , 5 . 73 - 5 . 78 ( m , 1 H ) , 4 . 25 - 4 . 33 ( m , 1 H ) , 4 . 10 - 4 . 17 ( m , 1 H ) , 3 . 98 - 4 . 06 ( m , 2 H ) , 3 . 73 ( s , 3 H ) , 2 . 97 ( s , 3 H ) , 2 . 17 ( s , 3 H ) , 1 . 32 ( t , J = 7 . 2 Hz , 3 H ) . LCMS : [ ( M + 1 ) ] + = 461 . 9 .