From the TLC, it was easy to
determine if there was still anthracene present in the product,
though the quantity is unknown. If anthracene was present, the
product was washed again with toluene and the sample was again
analyzed by TLC. This procedure was repeated until the product
was pure anthraquinone, which typically took no more than two
Table 1. Typical Results from Instructor and Student Experiments
for the Oxidation of Anthracene to Anthraquinone
Conditions Average TON
Average Yield
Anthraquinone (%)
Normala 12 ( 0.5 40 ( 1
Half H2O2 14 ( 2 50 ( 1
Double catalyst 9 ( 1 60 ( 2
55 C 3.5 ( 1 12 ( 2
40 C 1 ( 0.5 3 ( 0.5
1h 5 ( 0.5 17 ( 1
4 h 22 ( 3 73 ( 5
No Catalyst 0 0
No H2O2 0 0
Double catalyst at 40 C0 0
Half everything 6 ( 1 16 ( 1
7.5 mL H2O2, 300 mg
anthracene, 25 mg catalyst,
and 10 mL ethyl acetate
10 ( 0.5 53 ( 1
a Normal conditions are 500 mg anthracene, 25 mg catalyst, 20 mL ethyl
acetate, 15 mL hydrogen peroxide at reflux for 2 h.
1157 dx.doi.org/10.1021/ed100843a |J. Chem. Educ. 2011, 88, 1155–1157
Journal of Chemical Education LABORATORY EXPERIMENT
washings. Because running the TLC consumes a small amount of
product, it was important to weigh the washed compound before
taking a sample for TLC.