1 H NMR ( CDCl 3 ) , δ ( ppm ) : 7 . 66 ( s , 2 H ) , 7 . 31 ( d , 2 H ) , 6 . 90 ( d , 2 H ) , 2 . 87 ( d , 4 H ) , 1 . 68 ( m , 2 H ) , 1 . 20 - 1 . 50 ( m , 16 H ) , 0 . 82 - 1 . 00 ( m , 12 H ) , 0 . 20 - 0 . 58 ( s , 18 H ) .