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Page 1: A comparative study of aerobic oxidation of turpentine

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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.

PHYSICOCHEMICAL STUDIES������������������������ ������������������������

OF SYSTEMS AND PROCESSES

A Comparative Study of Aerobic Oxidation of TurpentineS. 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, RussiaUral State University, Yekaterinburg, Russia

Received March 23, 2007

Abstract�The catalytic activity exhibited in turpentine oxidation at elevated pressure by cobalt coordinationcompounds, some transition metal compounds, in particular, polyoxometallate with spherical nanoclusters(Mo132), vanadium oxide bronze, and cobalt complexes immobilized on AN-241 anion exchanger was studied.

DOI: 10.1134/S1070427208010126

It is known that oxidation of �-pinene with molec-ular oxygen leads to allyl oxidation products andoxygen-containing compounds formed by oxidation ofthe methyl group adjacent to the double bond; epoxi-dation products are also formed [1]. The ratio of theoxidation products can be apparently controlled bychoosing appropriate catalysts. Catalytic oxidation of�-pinene still attracts researchers’ attention [2�4].At the same time, today the main source of �-pineneis sulfate turpentine, which is mainly used as solvent.Therefore, to extend the possibilities of preparingpractically important �-pinene derivatives, it is ap-propriate to study its oxidation using as substratecommercial turpentine. Proceeding with studies in thisfield [5], we examined the activity of a series ofhomogeneous and heterogeneous catalysts in the oxi-dation of turpentine at elevated pressure of molecularoxygen (�1.3 atm). Apparently, slightly elevated oxy-gen pressure should lead to a decrease in the oxidationtemperature (in contrast to [6] where the reaction wasperformed at reduced pressure) and in the yield ofhigh-boiling oxidation products. As catalysts we usedhomogeneous complexes, including those capable ofreversible oxygen binding and suitable for oxidationof 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(VOBs) Cu0.6 �V2O5 [7], for liquid-phase peroxideoxidation of aromatic compounds.

EXPERIMENTAL

The reaction mixture was analyzed with a Chrom-5chromatograph 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[5], in a setup with a temperature-controlled reactorfixed 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 50�C. We usedturpentine [GOST (State Standard) 1571�82] 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 �-pinene oxidationwere plotted. For each kinetic curve, we determinedthe initial rate by extrapolation of the measurementresults after completion of the induction period, usinga pseudo-first-order equation [5].

In addition, we determined the specific oxidationrate. The complexes Co(acac)2 and CoSalen were pre-pared by procedures described in [5]. The catalystactivities were evaluated by the rate of �-pinene con-sumption in the reaction mixture. The �-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. Thisquantity is defined as the ratio of the initial rate of�-pinene oxidation to the molar concentration of thecatalyst, Vsp = V0/[Cat] (see table).

Among the heterogeneous catalysts tested, thehighest initial oxidation rate was observed with vana-dium oxide bronze of the composition Cu0.6V2O5.

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A COMPARATIVE STUDY OF AEROBIC OXIDATION OF TURPENTINE 53

Oxidation of �-pinene in the presence of homogeneous and heterogeneous catalysts. T = 500�C, P = 1.3 atm, solventacetonitrile������������������������������������������������������������������������������������Sample �

Catalyst� Sample � Molar ratio � V0, mol l�1 min�1 �

Vspno. � �weight, g��-pinene : solvent* : catalyst� for �-pinene �������������������������������������������������������������������������������������

� � � � �1 : 11.05 : 0 � - 0.00219 � �

1 �AN-251 + CoCl2** � 0.0242 �1 : 11.05 : 0.0000837 � - 0.0217 � 19 7002 �Co(acac)2 � 0.0395 �1 : 11.05 : 0.0117 � - 0.0186 � 1223 �CoSalen � 0.0497 �1 : 11.05 : 0.0117 � - 0.0724 � 4734 �Cu0.6�V2O5 � 0.0337 �1 : 11.05 : 0.0152 � - 0.0684 � 3345 �(NH4)42[MoVI

72MoV60O372(HCO2)30� � 0.0337 �1 : 11.05 : 0.0001169 � - 0.0567 � 37 000

�(H2O)72] �30HCO2Na �250H2O** � � � �������������������������������������������������������������������������������������

* For calculation simplicity; actually the solvent also contained other turpentine components (apart from �-pinene and its oxidationproducts).

** In calculation of Vsp for sample nos. 1 and 5, the molecular weights of both catalysts were taken equal, 22 000.

This catalyst can be used repeatedly. Along with thecompounds synthesized previously, we tested in tur-pentine oxidation polyoxometallate with sphericalnanoclusters of the composition (NH4)42[MoVI

72 �MoV

60O372(HCO2)30(H2O)72] � 30HCO2Na � 250H2O[8].

It should be noted that the resistance of the spheri-cal molybdenum complex to atmospheric oxygen wasevaluated in [9] by spectrophotometry and by photo-voltaic effect measurement, and the tendency of thecomplex to gradual oxidation and degradation, accel-erating under the action of light, was revealed. At thesame time, the oxidation of �-pinene without solventin the presence of the polyoxometallate was slow.

A heterogeneous analog of Co(II) picoline com-plex, prepared by sorption of Co(II) ions on AN-251anion exchanger, proved to be the least active amongthe heterogeneous catalysts, despite the fact that thecorresponding homogeneous catalyst showed highselectivity in oxidation of �-pinene to verbenone [10].

According to GLC data, elevated pressure appreci-ably increases the �-pinene conversion. The �-pinene

t, min

log c [M]

�-Pinene concentration c as a function of time t. Oxidationin the presence of Co(acac)2. log c = �0.0011t + 0.8715;R2 = 0.8375.

conversion reached 78% (at 45% conversion, theselectivity of verbenone formation was about 12%),at the highest oxidation rate, with the homogeneousCo(Salen) catalyst. It is appropriate to use this catalystfor oxidation of sulfate turpentine, as it is a one-usecatalyst.

CONCLUSIONS

(1) The conditions chosen for sulfate turpentineoxidation (P �1.3 atm) ensure increased conversion of�-pinene and confirm the necessity of searching forcompounds generating radical oxygen species as cata-lysts for �-pinene oxidation to verbenol and verbe-none.

(2) The presence of other terpene hydrocarbons,along with �-pinene, in turpentine reduced the nega-tive effect of the most active radical species on theinitial oxidation process.

(3) Heterogeneous catalysts are appropriate foroxidation of oleoresin turpentine, because this rawmaterial contains no sulfur compound and there is norisk of catalyst poisoning.

ACKNOWLEDGMENTS

The authors are grateful to V.L. Volkov for thesample of VOB of the composition Cu0.6 �V2O5and to V.P. Fedin for the sample of the polyoxomet-allate (NH4)42[MoVI

72MoV60O372(HCO2)30(H2O)72] �

30HCO2Na �250H2O.

REFERENCES

1. Kislitsin, A.N., Klabukova, I.N., and Trofimov, A.N.,Khim. Rast. Syr’ya, 2004, no. 3, pp. 109�116.

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RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 81 No. 1 2008

54 MEN’SHIKOV et al.

2. Bhattacharjee, S. and Anderson, J.A., Catal. Lett.,2004, vol. 95, nos. 3�4, pp. 119�125.

3. Kuznetsova, N.I., Kuznetsova, L.I., Kirillova, N.V.,et al., Izv. Ross. Akad. Nauk, Ser. Khim., 2003, no. 7,pp. 1462�1468.

4. RF Patent 2 250 208.5. Men’shikov, S.Yu., Sennikov, M.Yu., Romano-

va, Yu.V., et al., Zh. Org. Khim., 2004, vol. 40, no. 6,pp. 830�833.

6. Patlasov, V.P., Savinykh, V.I., Kushnir, S.R., andLukoyanov, V.P., Izv. Vyssh. Uchebn. Zaved., Lesn.Zh., 1999, no. 5, pp. 74�82.

7. Men’shikov, S.Yu., Vurasko, A.V., Petrov, L.A.,

et al., Neftekhimiya, 1992, vol. 32, no. 2, pp. 162�164.

8. Muller, A., Fedin, V.P., Kuhlmann, G., et al., Chem.Commun., 1999, no. 10, pp. 927�929.

9. Ostroushko, A.A., Sennikov, M.Yu., Artemov, M.Yu.,et al., in 9-ya Mezhdunarodnaya konferentsiya �Fizi-ko-khimicheskie protsessy v neorganicheskikh materi-alakh� (9th Int. Conf. �Physicochemical Processes inInorganic Materials�), Kemerovo, September 22�25,2004, vol. 1, pp. 422�425.

10. Volchko, K.P., Ragoza, L.N., Salakhutdinov, N.F.,et al., Preparativnaya khimiya terpenodiov (Prepara-tive Chemistry of Terpenoids), Novosibirsk: Sib. Otd.Ross. Akad. Nauk, 2005, book 1.


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