ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 1, pp. 52!54. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + S.Yu. Men’shikov, Yu.V. Mishina, Yu.V. Mikushina, A.A. Ostroushko, 2008, published in Zhurnal Prikladnoi Khimii, 2008,
Vol. 81, No. 1, pp. 56 !58.
OF SYSTEMS AND PROCESSES
A Comparative Study of Aerobic Oxidation of Turpentine
S. Yu. Men’shikov, Yu. V. Mishina, Yu. V. Mikushina, and A. A. Ostroushko
Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, Yekaterinburg, Russia
Ural State University, Yekaterinburg, Russia
Received March 23, 2007
Abstract-The catalytic activity exhibited in turpentine oxidation at elevated pressure by cobalt coordination
compounds, some transition metal compounds, in particular, polyoxometallate with spherical nanoclusters
), vanadium oxide bronze, and cobalt complexes immobilized on AN-241 anion exchanger was studied.
It is known that oxidation of a-pinene with molec-
ular oxygen leads to allyl oxidation products and
oxygen-containing compounds formed by oxidation of
the methyl group adjacent to the double bond; epoxi-
dation products are also formed . The ratio of the
oxidation products can be apparently controlled by
choosing appropriate catalysts. Catalytic oxidation of
a-pinene still attracts researchers’ attention [23 4].
At the same time, today the main source of a-pinene
is sulfate turpentine, which is mainly used as solvent.
Therefore, to extend the possibilities of preparing
practically important a-pinene derivatives, it is ap-
propriate to study its oxidation using as substrate
commercial turpentine. Proceeding with studies in this
field , we examined the activity of a series of
homogeneous and heterogeneous catalysts in the oxi-
dation of turpentine at elevated pressure of molecular
oxygen (~1.3 atm). Apparently, slightly elevated oxy-
gen pressure should lead to a decrease in the oxidation
temperature (in contrast to  where the reaction was
performed at reduced pressure) and in the yield of
high-boiling oxidation products. As catalysts we used
homogeneous complexes, including those capable of
reversible oxygen binding and suitable for oxidation
of sulfate turpentine because of no need in their regen-
eration. We also tested a series of heterogeneous cata-
lysts containing transition metals (Cu, V, Mo, Co),
taking into account successful use of these com-
pounds, in particular, of vanadium oxide bronzes
, for liquid-phase peroxide
oxidation of aromatic compounds.
The reaction mixture was analyzed with a Chrom-5
chromatograph equipped with a thermal conductivity
detector and a 1.5-m glass column with DC-550 sta-
tionary phase. Carvone was used as internal reference.
Experiments were performed, in accordance with
, in a setup with a temperature-controlled reactor
fixed in a high-speed rocker. Experiments were per-
formed at 300 rockings per minute at elevated pres-
sure (1.3 atm) and a temperature of 50oC. We used
turpentine [GOST (State Standard) 1571382] as sub-
strate, acetonitrile as solvent, and various homogene-
ous and heterogeneous catalysts.
Samples of the reaction mixture were taken at reg-
ular intervals and subjected to chromatographic anal-
ysis, and the kinetic curves of a-pinene oxidation
were plotted. For each kinetic curve, we determined
the initial rate by extrapolation of the measurement
results after completion of the induction period, using
a pseudo-first-order equation .
In addition, we determined the specific oxidation
rate. The complexes Co(acac)
and CoSalen were pre-
pared by procedures described in . The catalyst
activities were evaluated by the rate of a-pinene con-
sumption in the reaction mixture. The a-pinene con-
tent was determined by gas chromatography. The de-
pendence log c = f (t) is linear (see figure).
The common criterion of performance of homo-
geneous and heterogeneous catalysts under the exam-
ined conditions is the specific oxidation rate. This
quantity is defined as the ratio of the initial rate of
a-pinene oxidation to the molar concentration of the
/[Cat] (see table).
Among the heterogeneous catalysts tested, the
highest initial oxidation rate was observed with vana-
dium oxide bronze of the composition Cu