Bismuth (III) nitrate supported onto silica gel, a new catalyst for acetylation of alcohols and phenols under microwave irradiation

Article abstract of DOI:10.1080/10426500490485075

Bismuth (III) nitrate supported onto silica gel is found to be efficient catalyst for acetylation of alcohols, phenols and naphthals in the presence of acetic anhydride under microwave irradiation in solventless system.

Full text of DOI:10.1080/10426500490485075

This article was downloaded by: [McMaster University]
On: 14 May 2013, At: 13:24
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH,
UK
Phosphorus, Sulfur, and Silicon
and the Related Elements
Publication details, including instructions for
authors and subscription information:
http://www.tandfonline.com/loi/gpss20
BISMUTH (III) NITRATE
SUPPORTED ONTO SILICA
GEL, A NEW CATALYST FOR
ACETYLATION OF ALCOHOLS
AND PHENOLS UNDER
MICROWAVE IRRADIATION
a
a
Karim Asadolah & Majid M. Heravi
a
Department of Chemistry, Faculty of Science,
Azzahra University, Vanak, Tehran, Iran
Published online: 16 Aug 2010.
To cite this article: Karim Asadolah & Majid M. Heravi (2004): BISMUTH (III) NITRATE
SUPPORTED ONTO SILICA GEL, A NEW CATALYST FOR ACETYLATION OF ALCOHOLS AND
PHENOLS UNDER MICROWAVE IRRADIATION, Phosphorus, Sulfur, and Silicon and the
Related Elements, 179:11, 2335-2339
To link to this article: http://dx.doi.org/10.1080/10426500490485075
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-
and-conditions
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan,
sub-licensing, systematic supply, or distribution in any form to anyone is
expressly forbidden.

The publisher does not give any warranty express or implied or make any
representation that the contents will be complete or accurate or up to
date. The accuracy of any instructions, formulae, and drug doses should be
independently verified with primary sources. The publisher shall not be liable
for any loss, actions, claims, proceedings, demand, or costs or damages
whatsoever or howsoever caused arising directly or indirectly in connection
with or arising out of the use of this material.

Phosphorus, Sulfur, and Silicon, 179:2335–2339, 2004
Copyright ꢀC Taylor & Francis Inc.
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500490485075
BISMUTH (III) NITRATE SUPPORTED ONTO SILICA
GEL, A NEW CATALYST FOR ACETYLATION
OF ALCOHOLS AND PHENOLS UNDER
MICROWAVE IRRADIATION
Karim Asadolah and Majid M. Heravi
Department of Chemistry, Faculty of Science, Azzahra
University, Vanak, Tehran, Iran
(
Received March 18, 2004; accepted May 4, 2004)
Bismuth (III) nitrate supported onto silica gel is found to be efficient
catalyst for acetylation of alcohols, phenols and naphthals in the pres-
ence of acetic anhydride under microwave irradiation in solventless
system.
Keywords: Acetylation; alcohols; bismuth (III) nitrate; microwave
irradiation; solventless system
INTRODUCTION
Esters have potential in industry because of their use in fragrance, fla-
1
vors, surfactants, plasticizers, and as solvents. The protections of hy-
droxyl groups of alcohols and phenols by the formation of esters is of par-
2
mount importance in organic chemistry. In general, acetylation takes
place by reaction of alcohols and phenols with acid anhydride in the
3
presence 4-(dimethylamino)pyridine (DMAP), 4-pyrrolidinopyridine
4
5
6
(
PPY), tributyl phosphine, cobalt(II) chloride, or trimethyl silyl
7
8
trifluoromethane sulfonate. Scandium trifluoromethane sulfonate,
Sc(NTF)3, silica gel-supported Ce(SO )3 and NaHSO4, vanadyl(IV)
acetate, triphenylphosphine and carbon tetraboromide, and bis-
muth(III) salts are other reagents for this purpose. In addition to the
9
4
10
1
1
12
1
3
1
4
above catalysts, tertiary amines such as triethylamine and pyridine,
toluene-p-sulfonic acid,15 zinc chloride, montmorillonite K-10, KSF,
16
17
The authors are thankful to Azzahra University research council for partial financial
support.
Address correspondence to Karim Asadolah, Department of Chemistry, Faculty of
Science, Azzahra University, Vanak, Tehran, Iran. E-mail: mmheravi@azzahra.ac.ir
2
335

2
336
K. Asadolah and M. M. Heravi
HZSM-360 zeolite,18 and sulfuric acid adsorbed on silicagel19 are also
known for the acetylation of alcohols and phenols. All of these methods
have their own merits and drawbacks. Pyridine and its derivatieves
have an unpleasant and irritant odor, and they are not easy to remove.
Tributyl phosphine is highly flammable and expensive. Some of the
above catalysts suffer from inherent disadvantages such as high cost,
poor regioselectivity, and affording the elimination of by-product in the
case of tert alcohols. Due to the importance of esters, introduction of
new methods and catalysts are still in demand.
In recent years, the organic reactions on solid supports have gained
popularity because of their selectivity and associated ease of ma-
nipulation. Since only the polar reactants adsorbed on the surface
of various mineral supports absorb microwaves (MW), a variety of
reagents supported on such surfaces can be utilized for the enhance-
ment of organic reaction using a simple microwave oven. Microwave-
enhanced chemical reactions, especially under solvent-free conditions,
have several advantages over the conventional reactions in view of
the rapid reaction rates attained and higher yields of pure products
2
0
obtained.
Bismuth compounds are attractive candidates for use in green chem-
istry, and the application of bismuth (III) compounds in organic reaction
transformation has been recently reviewed.2
1
In continuation of our ongoing program on MW-assisted solvent-free
2
2
23
reactions and our interest in using bismuth (III) nitrate, the less
toxic of heavy metals, herein we wish to report a facile acetylation proto-
col that utilizes bismuth (III) nitrate impregnated onto silica gel under
microwave irradiation.
The reactions were simply conducted by mixing of neat substances
with bismuth (III) nitrate supported onto silica gel and acetic anhydride
in an open container. The mixture is placed in a household microwave
oven in solid state. The progress of the reaction was monitored by thin
layer chromatography (TLC). As shown in Table I. Primary, secondary,
and benzylic alcohols are acetylated in excellent yields under this condi-
tion. 2-Hydroxy benzyl alcohol gave a poor yield. However, when 2 moles
ratio of bismuth (III) nitrate was used, it was converted to the corre-
sponding diacetate efficiently (Table I, entry 6). Tertiary alcohols such
as t-butyl alcohol were not converted to acetate in the above reaction
condition.
In order to extend the scope of this reaction, phenol was also acety-
lated in excellent yields. It is also noteworthy to mention that in this
reaction bismuth (III) nitrate did not show the disadvantage of giving
nitrate side products observed in the reaction of aromatic compounds
with this catalyst.24

Acetylation
2337
2
TABLE I Acylation of Alcohols and Phenols with Ac O, Catalyzed by
3 3
Bi(NO ) /Silica Gel under Microwave Irradiation in Solventless System
Reaction
Entry
Substrate
time (min)
Products
Yield (%)
1
2
3
4
5
6
7
8
9
n-Amylalcohol
2-Octanol
2
4
3
3
2
2
3
2
1
n-Amylacetate
2-Octyl acetate
85
79
87
98
85
80
75
83
80
Cyclohexanol
Cinnamyl alcohol
Benzyl alcohol
2-Hydroxybenzyl alcohol
Benzoin
Cyclohexyl acetate
Cinnamyl acetate
Benzyl acetate
2-Acetoxybenzyl acetate
Benzoin acetate
Phenol acetate
Phenol
Naphthol
Naphthyl acetate
Yields refer to isolated product.
In summary, an efficient, rapid, and high-yielding method for the
acetylation of alcohols, phenols, and naphthols has been developed. Mild
condition and easy workup procedure are two other advantages of this
method. We believe this methodology will find application in organic
synthesis.
SCHEME 1
EXPERIMENTAL
All products were characterized by comparison of their physical and
spectral data with those of authentic samples. Bismuth (III) nitrate
was purchased and used as received. Yields refer to isolated products,
although we did not observe any accident using bismuth (III) nitrate
in microwave oven, using of microwave in an efficient hood is highly
recommended.
Acetylation of alcohols and phenols with Ac2O, catalyzed by
Bi(NO3)3, supported onto silica gel under microwave irradiation.
General Procedure
An appropriate alcohol or phenol (1 mmol) and acetic anhydride (2
equiv. For each hydroxy group of alcohol) were mixed thoroughly in a

2
338
K. Asadolah and M. M. Heravi
beaker using a spatula. To this mixture bismuth (III) nitrate (0.25 mmol
for each hydroxy group) supported onto silica gel (2 equiv. weight of
Bi(NO3)3) was added and mixed thoroughly. The beaker was placed
in a microwave oven for the indicated time (Table I). The progress of
the reaction was monitored by TLC, using EtOAc:Et2O (1:3) as elu-
ents. Upon completion of the reaction, CH2Cl2 (10 ml) was added to the
residue. The mixture was filtered off, and a solution of NaHCO3 (5%)
was added to the filtrate. The organic layer was separated, dried, and
evaporated to dryness under reduced pressure to afford the correspond-
ing acetate (Table I).
REFERENCES
[
[
1] W. Rumenschneider, Ester, organic, in Ullman’s Encyclopedia of Industrial Chem-
istry, 5th ed., Vol. A9 (VCH, Germany, 1997), p. 565.
2] T. W. Grien and P. G. M. Wutz, Protective Groups in Organic Synthesis, Vol. II (Wiley,
New York, 1991).
[
[
[
3] G. Hofle, V. Steglich, and H. Varhruggen, Angew. Chem. Int. Ed. Engl., 17, 56 (1978).
4] E. F. V. Seriven, Chem. Soc. Rev., 12, 1291 (1983).
5] a) E. Velgs and S. T. Diver, J. Am. Chem. Soc., 115, 3358 (1993); b) E. Velgs, N. S.
Bemdt, L. M. Cown, S. T. Diver, M. Mingras, S. Lim, P. A. Oliver, and M. J. Peterson,
J. Org. Chem., 58, 7286 (1993).
[
[
[
6] a) S. Ahmad and J. Iqlal, J. Chem. Soc. Chem. Commun., 114, 1987; b) J. Iqlal and
K. Srivastava, J. Org. Chem, 57, 2001 (1992).
7] P. A. Procopiou, S. P. D. Baugh, S. S. Flack, and G. G. A. Inglis, J. Chem. Soc. Chem.
Commun., 2625 (1996).
8] a) K. Ishihara, M. Kubota, H. Kuvhara, and H. Yamamoto, J. Org. Chem., 117, 4413
(
1995); b) K. Ishihara, M. Kubota, H. Kuvhara, and H. Yamamoto, J. Org. Chem.,
1, 4560 (1996); c) I. Shima and T. Mukavyarn, Chem. Lett., 677 (1997).
9] K. Ishihara, M. Kubota, and H. Yamamoto, Synlett, 265 (1996).
6
[
[
[
10] T. Nishiguchi and H. Taya, J. Chem. Soc. Trans., 1, 172 (1990).
11] B. M. Choudary, M. L. Kantam, V. Neeraja, T. Bandyopo, and P. N. Reddy, J. Molec-
ular Catalysis, 140, 25 (1999).
[
[
[
12] H. H. Isahiro, M. Kimie, S. Hitoshi, S. Toshio, and A. Masayoshi, Tetrahedron, 54,
5
845 (1998).
13] I. Mohammad Poor Boltark, H. Aliyan, and A. K. Khosropour, Tetrahedron, 57, 5851
2001).
(
14] a) R. I. Zhdanov and S. M. Zhenolarova, Synthesis, 222 (1975); b) D. Harton, Org.
Synth. Collective, 5, 1 (1973).
[15] A. C. Cope and E. C. Herick, Org. Synth. Collective, 4, 304 (1963).
[16] R. H. Baker and F. G. Bardwell, Org. Synth. Collective, 3, 141 (1955).
[17] A. Yiao, T. Snili, and T. H. Ding, Chem. Commun., 1389 (1997).
[18] R. Ballini, G. Basic, and S. Carloxi, Tetrahedron Lett., 39, 6049 (1998).
[19] M. A. Bigdeli, N. Nahid, and M. M. Heravi, Sran. J. Chem. Chem. Eng., 19, 37
(
2000).
[
[
20] K. S. Varma and R. Dahiya, Tetrahedron Lett., 39, 1307 (1998) and references cited
therein.
21] N. M. Leonard, L. C. Wieland, and R. S. Mohan, Tetrahedron, 58, 8373 (2002).

Acetylation
2339
[
[
[
22] a) M. M. Heravi, D. Ajami, and M. Ghassemzadeh, Synthesis, 3, 393 (1999); b) D.
Ajami, M. Ghassemzadeh, and M. M. Mojtahedi, Tetrahedron Lett., 40, 561 (1999);
c) M. M. Heravi, D. Ajami, K. Aghapoor, and M. Ghassemzadeh, Chem. Commun.,
8
33 (1999).
23] a) Sh. Khaleghi, M. M. Heravi, and L. Fotouhi, Phosphorus, Sulfur, and Silicon,
78, 155 (2003); b) M. Tajbakhsh, M. M. Heravi, A. Hoseini, and A. Shahrezaiee,
1
Phosphorus, Sulfur, and Silicon, 178, 773 (2003); c) M. M. Heravi, S. Yazdanpanah,
H. A. Oskooiee, and M. M. Mojtahedi, J. Chem. Res., 2, 129 (2004).
24] S. Susanta and B. K. Bimal, Tetrahedron Lett., 41, 8017 (2000).