Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 40:157–159, 2010
Copyright © Taylor & Francis Group, LLC
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533171003629089
Oxidation of Benzoins with Ferric (III) Nitrate Supported
on Aluminum Silicate
Ji-Dong Lou,1 Yi-Chun Ma,1 Negin Vatanian,2 Qiang Wang,2 and Changhe Zhang3
1College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, China
2Sirnaomics, Inc., Gaithersburg, MD, USA
3Instituto de Biologia Experimental e Tecnologia, Universidade Nova de Lisboa, Oeiras, Portugal
ture is magnetically stirred. A solution of benzoin (212 mg,
1 mmol) in dichloromethane (3 mL) is added, and after 2 h
at reflux the solid is filtered and washed with dichloromethane
(3 × 5 mL). The combined filtrates are evaporated to give crude
product, which is purified by preparative TLC with hexane:ethyl
acetate (7:3) to afford 202 mg (95%) benzil.
The preparation of benzils by oxidation of corresponding ben-
zoins using ferric (III) nitrate nonahydrate supported on aluminum
silicate reagent under heterogeneous conditions and reflux in yields
between 82–95% is described. The main advantage of this oxidation
is that the reaction time is much shorter as compared to the other
reported ferric (III) nitrate nonahydrate based reagents, and it is
an extension of application for the ferric (III) nitrate nonahydrate
supported on aluminum silicate reagent as well.
Oxidation of Benzoin to Benzil
1H NMR (300 MHz, CDCl3): δ (ppm) 7.9-7.8 (4H, m, 2 ×
Ar-H); 7.6-7.4 (6H, m, 2 × Ar-H). FT-IR (KBr): 1680 (C=O),
1595 (C=C).
Keywords benzils, benzoins, ferric (III) nitrate, oxidation, supported
reagent
Oxidation of 4,4ꢀ-Dimethylbenzoin to
INTRODUCTION
4,4ꢀ-Dimethylbenzil
The preparation of benzils by way of oxidation of benzoins
is one of the important reactions in organic synthesis, which has
received a great deal of attention due to the practical applica-
tions of the benzils, such as photosensitive agents and synthetic
agents, in organic and pharmaceutical chemistry.[1] Of this oxi-
dation reaction, several oxidants have been employed, especially
ferric (III) nitrate nonahydrate based reagents for instance, ferric
nitrate–clay,[2] ferric nitrate–silica,[3] ferric nitrate-graphite,[4]
ferric nitrate-kieselguhr,[5] etc., which reagents have received
good results. Although a diversity of ferric (III) nitrate nonahy-
drate based reagents is available, developments of convenient,
selective, and mild procedures are still an important objective of
current relevance. Consequently, introduction of new methods
or reagents is still fraught with experiment challenges, especially
in search of versatile and selective reagents.
1H NMR (300 MHz, CDCl3): δ (ppm) 7.6 (4H, d, J = 9Hz,
2 × Ar-H); 7.2 (4H, d, J = 9Hz, 2 × Ar-H); 2.4 (6H, s, 2 ×
CH3). FT-IR (KBr): 1680 (C=O), 1600 (C=C).
Oxidation of 4,4ꢀ-Dimethoxybenzoin to
4,4ꢀ-Dimethoxybenzil
1H NMR (300 MHz, CDCl3): δ (ppm) 7.6 (4H, d, J = 9Hz,
2 × Ar-H); 6.9 (4H, d, J = 9Hz, 2 × Ar-H); 3.8 (6H, s, 2 ×
OCH3). FT-IR (KBr): 1675 (C=O), 1600 (C=C).
Oxidation of 4,4ꢀ-Dichlorobenzoin of 4,4ꢀ-Dichlorobenzl
1H NMR (300 MHz, CDCl3): δ (ppm) 7.6 (4H, d, J = 9Hz,
2 × Ar-H); 7.1 (4H, d, J = 9Hz, 2 × Ar-H). FT-IR (KBr): 1680
(C=O), 1595 (C=C).
EXPERIMENTAL
Oxidation of 2,2ꢀ-Furoin to 2,2ꢀ-Furil
Oxidation of Benzoin to Benzil: Typical Procedure
The Fe(NO3)3- aluminum silicate reagent[6] (2.2 g) is placed
in a flask together with dichloromethane (50 mL) and the mix-
1H NMR (300 MHz, CDCl3): δ (ppm) 7.6-7.5 (2H, m, 2 ×
HCO); 7.2-7.1 (2H, m, 2 × CH); 6.5-6.4 (2H, m, 2 × CH).
FT-IR (KBr): 1670 (C=O).
Received 23 September 2009; accepted 17 January 2010.
Address correspondence to Ji-Dong Lou, College of Life Sciences,
China Jiliang University, Hangzhou, Zhejiang 310018, China. E-mail:
RESULTS AND DISCUSSION
To the best of our knowledge, ferric nitrate nonahydrate
[Fe(NO3)3·9H2O] based reagents are, probably, the good choice
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