Next Article in Journal
Chemical Constituents of Piper betle Linn. (Piperaceae) Roots
Previous Article in Journal
Highly Lipophilic Benzoxazoles with Potential Antibacterial Activity
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

An Efficient and Selective Solvent-free Oxidation of Alcohols by Shaking with Chromium Trioxide Supported on Aluminium Silicate

College of Life Sciences, China Jiliang University, Hangzhou, P.R. China
Institute of Chemical and Biological Technology, New University of Lisbon, Portugal
Author to whom correspondence should be addressed.
Molecules 2005, 10(7), 794-797;
Submission received: 17 May 2004 / Revised: 14 January 2005 / Accepted: 15 January 2005 / Published: 31 August 2005


A selective oxidation of primary alcohols to the corresponding aldehydes by shaking with chromium trioxide supported on aluminium silicate at room temperature under solvent free conditions is reported. This new procedure can also oxidise secondary alcohols.


Recently considerable attention has been paid to the solvent free reactions [1]. These are not only of interest from an ecological point of view, but in many cases they also offer considerable synthetic advantages in terms of yields, selectivity and simplicity of the reaction procedures. These factors are especially important in industry. Therefore, some the traditional organic synthetic methods, which have long been carried out in solvents, may be modified to more modern, elegant, and safe versions.
One of the most important reactions of alcohols, which have long been the objective of many research papers, is their oxidation to the corresponding carbonyl compounds. Chromium (VI)-based reagents have been extensively used in organic synthesis [2,3,4]. The utility of chromium (VI) reagents in the above oxidative transformation is compromised due to their inherent toxicity, cumbersome preparation, and potential danger in terms of product isolation and waste disposal. The introduction of reagents on solid supports [5] has circumvented some of these problems and provided an attractive alternative in organic synthesis in view of the selectivity and associated ease of manipulation. Therefore, it is not surprising that a large number of chromium (VI)-based oxidants impregnated on solid supports have been explored [6,7,8,9,10,11,12,13,14,15,16,17,18,19], however, almost all of these procedures are performed under heterogeneous conditions, or assisted by microwave irradiation.

Results and Discussion

We have described a new reagent, chromium trioxide (CrO3) supported on aluminium silicate, for the heterogeneous selective oxidation of primary alcohols [16]. In connection with our recent work [20,21,22] we now report a novel oxidation of primary alcohols to the corresponding aldehydes using this supported reagent under solvent free conditions by shaking at room temperature without microwave irradiation (Scheme 1). This is the first time a shaking machine has been employed for this reaction, and its performance is very simple. We find that using shaking is much more effective than using a stirrer for this kind of solvent-free reactions. Some previous methods required the reactions to be heated, but in the present work, heating is unnecessary, and the reaction times are also quite reduced.
Scheme 1.
Scheme 1.
Molecules 10 00794 g001
The present method has several procedural advantages over heterogeneous oxidations [16], for instance, the reaction conditions are milder, the reaction times are shorter, and the work-ups are easier. In addition, compared to the few existing CrO3-based reagents used under solvent free conditions, such as chromium trioxide on wet alumina [23], and chromium trioxide with HZSM-5 zeolite [24], an important benefit of the present method is that there is no need to use microwave irradiation, an additional energy input. Furthermore, owing to the fact that the reaction takes place under solvent free conditions, the risk of combustion, the toxicity, and environmental pollution of solvents are reduced. In addition, the present method has been extended to oxidation of secondary alcohols.
In the present method, a 1.5 to 1 molar ratio of CrO3 to substrate is employed. First, the oxidant is carefully added to the substrate and the mixture is shaken mechanically at room temperature. The progress of the reaction is monitored by TLC. In general, the oxidations are completed within 60 min. The residue is then washed with dichloromethane or diethyl ether. Purification of the residue gives a product that is of acceptable purity for most purposes. As can be seen in Table 1, this method is generally applicable to a wide range of alcohols, and gives the corresponding aldehydes and ketones in good yields, thus comparing favourably with some traditional CrO3-based oxidation methods [25].


In conclusion, solvent free oxidation of primary and secondary alcohols using CrO3 supported on aluminium silicate at room temperature by shaking is a new and efficient method for the preparation of corresponding aldehydes and ketones.


Typical Procedure: Oxidation of Benzyl Alcohol to Benzaldehyde:

A mixture of benzyl alcohol (108 mg, 1 mmol) and CrO3-aluminium silicate reagent [16] (750 mg) is shaken mechanically (Horizontal oscillator, Model HY-2, Zhengji Instrument Co. Ltd.) at room temperature for 20 min. The progress of the reaction is monitored by TLC (aluminum-backed silica gel Merck 60 GF254 plates) using hexane-ethyl acetate (8:2) as eluent. The reaction mixture is then washed with CH2Cl2 (3 × 5 mL). The combined filtrates are evaporated to give crude product, which is purified by preparative TLC (hexane-ethyl acetate 8:2) to afford benzaldehyde (97 mg, 92%).
Table 1. Solvent free oxidation of alcohols with CrO3 supported on aluminium silicate.
Table 1. Solvent free oxidation of alcohols with CrO3 supported on aluminium silicate.
SubstrateReaction time (min)ProductaYield (%)
Molecules 10 00794 i00130 Molecules 10 00794 i00286
Molecules 10 00794 i00320 Molecules 10 00794 i00492
Molecules 10 00794 i00520 Molecules 10 00794 i00690
Molecules 10 00794 i00720 Molecules 10 00794 i00890
Molecules 10 00794 i00930 Molecules 10 00794 i01087
Molecules 10 00794 i01130 Molecules 10 00794 i01280
Molecules 10 00794 i01340 Molecules 10 00794 i01485
Molecules 10 00794 i01520 Molecules 10 00794 i01695
a All the products are known compounds and were identified by comparison of their IR spectra or by the IR spectra and melting points of their 2,4-dinitrophenyl- hydrazones with literature values [26].


  1. For a more recent review; see: Sineriz, F.; Thomassigny, C.; Lou, J.-D. Current Organic Synthesis 2004, 1, 137.
  2. Freeman, F. Organic Synthesis by Oxidation with Metal Compounds; Mijs, W. J., de Jonge, C. R. H. I., Eds.; Plenum Press: New York, 1986; pp. 68–81. [Google Scholar]
  3. Haines, A. H. Methods for the Oxidation of Organic Compounds, Alcohols, Alcohol Derivatives, Alkyl halides, Nitroalkanes, Alkyl Azides, Carbonyl Compounds, Hydroxyarenes and Aminoarenes. Academic Press: London, 1988; pp. 17–41. [Google Scholar]
  4. Ley, S. V.; Madin, A. Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon Press: London, 1991; Vol. 7, pp. 251–289. [Google Scholar]
  5. Laszlo, P. Preparative Chemistry Using Supported Reagents; Academic Press: San Diego, CA, 1987. [Google Scholar]
  6. Lalancette, J. M.; Rollin, G.; Dumas, P. Can. J. Chem. 1972, 50, 3058.
  7. Anderson, H.; Uh, H. Synth. Commun. 1973, 3, 115.
  8. Cainelli, G.; Cardillo, G.; Orena, M.; Sandri, S. J. Am. Chem. Soc. 1976, 98, 6737. [CrossRef]
  9. Filippo, S.; Chern, C. I. J. J. Org. Chem. 1977, 42, 2182.
  10. Santaniello, E.; Ponti, F.; Manzocchi, A. Synthesis 1978, 534.
  11. Cheng, Y.-S.; Liu, W.-L.; Chen, S. H. Synthesis 1980, 223.
  12. Frechet, J. M. J.; Derling, P.; Farrall, M. J. J. J. Org. Chem. 1981, 46, 1728. [CrossRef]
  13. Suggs, J. W.; Ytuarte, L. Tetrahedron Lett. 1986, 27, 437.
  14. Brunelet, T.; Jouitteau, C.; Gellbard, G. J. J. Org. Chem. 1986, 51, 4016. [CrossRef]
  15. Lou, J.-D.; Wu, Y.-Y. Chem. Ind. (London) 1987, 531.
  16. Lou, J.-D.; Wu, Y.-Y. Synth. Commun. 1987, 17, 1717.
  17. Lou, J.-D. Synth. Commun. 1989, 19, 1841.
  18. Khadilkar, B.; Chitnavis, A.; Khare, A. Synth. Commun. 1996, 26, 205.
  19. Lou, J.-D.; Lou, W.-X. Synth. Commun. 1997, 27, 3697.
  20. Lou, J.-D.; Xu, Z.-N. Tetrahedron Lett. 2002, 43, 6095.
  21. Lou, J.-D.; Xu, Z.-N. Tetrahedron Lett. 2002, 43, 6149. [CrossRef]
  22. Lou, J.-D.; Xu, Z.-N. Tetrahedron Lett. 2002, 43, 8843.
  23. Varma, R. S.; Saini, R. K. Tetrahedron Lett. 1998, 39, 1481.
  24. Heravi, M. M.; Ajami, D.; Tabar-Hydar, K.; Ghassemzadeh, M. J. J. Chem. Res. (S) 1999, 334.
  25. Fieser, L.; F. Fieser, M. Reagents for Organic Synthesis; John Wiley & Sons: New York, 1967; Vol. 1, pp. 144–147, and subsequent volumes in the series. [Google Scholar]
  26. (a)The Aldrich Library of FT-IR Spectra, 2nd edition; Aldrich Chemical Company: Milwaukee: WI, 1997.(b)The Merck Index, 13th edition; Merck Publishing: Rahway, NJ, 2001.(c)The Chapman & Hall/CRC Dictionary of Organic Compounds, 6th edition; CRC Press: Boca Raton, FL, 1995.
  • Sample Availability: Contact the authors.

Share and Cite

MDPI and ACS Style

Huang, L.; Lou, J.; Zhu, L.; Ping, L.; Fu, Y. An Efficient and Selective Solvent-free Oxidation of Alcohols by Shaking with Chromium Trioxide Supported on Aluminium Silicate. Molecules 2005, 10, 794-797.

AMA Style

Huang L, Lou J, Zhu L, Ping L, Fu Y. An Efficient and Selective Solvent-free Oxidation of Alcohols by Shaking with Chromium Trioxide Supported on Aluminium Silicate. Molecules. 2005; 10(7):794-797.

Chicago/Turabian Style

Huang, L., J. Lou, L. Zhu, L. Ping, and Y. Fu. 2005. "An Efficient and Selective Solvent-free Oxidation of Alcohols by Shaking with Chromium Trioxide Supported on Aluminium Silicate" Molecules 10, no. 7: 794-797.

Article Metrics

Back to TopTop