ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 7, pp. 1108–1109. © Pleiades Publishing, Ltd., 2009.
Published in Russian in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 7, pp. 1119–1120.
SHORT
COMMUNICATIONS
Bismuth(III) Nitrate-Catalyzed Solvent-Free Acetylation
of Alcohols and Phenols with Acetic Anhydride*
M. M. Heravi, F. K. Behbahani, Z. Daroogheha, and H. A. Oskooie
Department of Chemistry, School of Sciences, Alzahra University, Vanak, Tehran, Iran
e-mail: mmh1331@yahoo.com
Received December 10, 2005
DOI: 10.1134/S1070428009070203
Development of efficient and mild procedures for
the protection of hydroxy group in alcohols and phe-
nols is very important for synthetic organic chemistry.
One of the most common methods for the protection of
these compounds is their conversion into O-acetyl
derivatives. Protection of hydroxy group is often nec-
essary in the course of various transformations in
multistep syntheses, especially in the preparation of
polyfunctional compounds, such as nucleosides, carbo-
hydrates, steroids, and other natural products [1].
12, 93; CH≡CHCH2, 12, 97; cyclohexyl, 12, 93;
2-methylcyclohexyl, 12, 91.5; t-Bu, 12, 88;
PhCH=CHCH2, 12, 93; C5H11, 12, 87; Me, 12, 91;
4-BrC6H4, 2.3, 86; Ph, 2.3, 93; 4-O2NC6H4, 2.0, 85;
2-naphthyl, 3.0, 94.
Ac2O, Bi(NO3)3 · 5H2O, 25°C
ROH
ROAc
Advantages of the proposed procedure include the
use of 1 to 1.5 equiv of acetic anhydride and a catalytic
amount of bismuth(III) nitrate, mild solvent-free con-
ditions, and high yield. All reagents were commercial
products which were not subjected to additional puri-
fication.
A number of procedures for the preparation of
acetyl derivatives have been reported, including those
implying the use of homogeneous and heterogeneous
reagents, e.g., ZnCl2 [2], CoCl2 [3], K-10 montmorillo-
nite and KSF4 [4], Mg(ClO4)2 [5], etc. While searching
for new methods of transformation of functional
groups, we were especially interested in using various
neutral or almost neutral catalysts and used bis-
muth(III) salts in various syntheses [6–10]. In the
recent years, bismuth(III) nitrate efficiently catalyzed
synthesis of coumarins [11], oxidation of dihydro-
pyrimidinones [12], microwave-assisted deoximation
[13], chemoselective synthesis of acylals [14], and
oxidation of benzoins [15], thiols, and disulfides [16].
Typical procedure for the acetylation of alcohols
and phenols with acetic anhydride in the presence
of bismuth(III) nitrate. A mixture of 0.504 ml
(5 mmol) of benzyl alcohol, 0.7 ml (7.5 mmol) of
acetic anhydride, and 0.05 g (0.1 mmol) of Bi(NO3)3·
5H2O was stirred at room temperature until the reac-
tion was complete according to the TLC data. The
mixture was treated with 15 ml of 10% aqueous
sodium hydrogen carbonate and extracted with diethyl
ether (3×20 ml). The extracts were combined, dried
over Na2SO4, and evaporated, and the product was
identified by comparing its spectral parameters with
those of an authentic sample.
In the present communication we report on the use
of Bi(NO3)3·5H2O to catalyze mild and effective acet-
ylation of alcohols and phenols with acetic anhydride
at room temperature under solvent-free conditions. The
corresponding acetates were thus obtained in high
yield. Listed below are the R group in the substrate,
reaction time (h), and yield (%, according to the
GLC data): PhCH2, 12, 98; CH2=CHCH2, 12, 92;
Me2CHCH2CH2, 12, 96; Bu, 12, 91; s-Bu, 12, 95; i-Pr,
REFERENCES
1. Greene, T.W. and Wuts, P.G.M., Protective Groups in
Organic Synthesis, New York: Wiley, 1999, 3rd ed.
2. Baker, R.H. and Bordwell, F.G., Hauser, C.R., Hud-
son, B.E., Abramovitch, B., Shivers, J.C., and Spas-
sow, A., Organic Synthesis, Horning, E.C., Ed., New
York: Wiley, 1955, vol. 3, p. 141.
* The text was submitted by the authors in English.
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