1 H NMR ( DMSO - d 6 , 400 MHz ) δ ppm 12 . 02 ( s , 1 H ) , 9 . 90 ( s , 1 H ) , 9 . 04 ( s , 1 H ) , 8 . 10 - 8 . 05 ( m , 2 H ) , 7 . 81 ( d , J = 8 . 0 Hz , 1 H ) , 7 . 70 - 7 . 69 ( m , 2 H ) , 7 . 61 - 7 . 59 ( m , 1 H ) , 7 . 15 ( t , J = 54 . 4 Hz , 1 H ) , 6 . 57 ( s , 1 H ) , 2 . 86 ( s , 3 H ) . ( ESI ) : m / z 384 . 9 [ M + H ] +.