1 H NMR : ( 500 MHz , acetone - d 6 ) : δ ( ppm ) = 7 . 82 ( m , 8 H ) , 7 . 75 ( m , 4 H ) , 7 . 67 ( t , J = 7 . 8 Hz , 4 H ) , 7 . 45 ( m , 4 H ) , 7 . 35 ( m , 8 H ) , 7 . 25 ( t , J = 8 . 0 Hz , 2 H ) , 7 . 11 ( m , 8 H ) , 6 . 95 ( d , J = 8 . 6 Hz , 2 H ) , 6 . 74 ( m , 4 H ) , 6 . 66 ( t , J = 7 . 8 Hz , 4 H )