H3PW12O40 - A selective, environmentally benign, and reusable catalyst for the preparation of methoxymethyl and ethoxymethyl ethers and their deprotections under mild conditions

Article abstract of DOI:10.1139/V08-068

Different types of primary and secondary alcohols were efficiently transformed to their corresponding methoxymethyl (MOM) and ethoxymethyl (EOM) ethers in the presence of catalytic amounts of H₃PW ₁₂O₄₀ at room temperature under solvent-free conditions. Selective protection of primary and secondary alcohols in the presence of phenols and tertiary alcohols was achieved by this method. Deprotection of these ethers to their parent alcohols was also performed using this catalyst in ethanol under reflux conditions. We have also found that primary and secondary MOM- and EOM-ethers are selectively deprotected in the presence of phenolic and tertiary ones, methyl and benzyl ethers, esters, and trimethylsilyl ethers by this catalyst. The notable advantages of this protocol are high yields, short reaction times, easy work-up, non-toxicity, easy availability and handling, eco-friendly, and reusability of the catalyst.

Full text of DOI:10.1139/V08-068

831
H3PW12O40 — A selective, environmentally benign,
and reusable catalyst for the preparation of
methoxymethyl and ethoxymethyl ethers and their
deprotections under mild conditions
Iraj Mohammadpoor-Baltork, Majid Moghadam, Shahram Tangestaninejad,
Valiollah Mirkhani, and Arsalan Mirjafari
Abstract: Different types of primary and secondary alcohols were efficiently transformed to their corresponding
methoxymethyl (MOM) and ethoxymethyl (EOM) ethers in the presence of catalytic amounts of H3PW12O40 at room
temperature under solvent-free conditions. Selective protection of primary and secondary alcohols in the presence of
phenols and tertiary alcohols was achieved by this method. Deprotection of these ethers to their parent alcohols was
also performed using this catalyst in ethanol under reflux conditions. We have also found that primary and secondary
MOM- and EOM-ethers are selectively deprotected in the presence of phenolic and tertiary ones, methyl and benzyl
ethers, esters, and trimethylsilyl ethers by this catalyst. The notable advantages of this protocol are high yields, short
reaction times, easy work-up, non-toxicity, easy availability and handling, eco-friendly, and reusability of the catalyst.
Key words: methoxymethylation, ethoxymethylation, protection, deprotection, heteropoly acid.
Résumé : Opérant à la température ambiante, dans des conditions sans solvant et en présence de quantités catalytiques
de H3PW12O40, il est possible de transformer d’une façon efficace divers types d’alcools primaires et secondaires en
éthers méthoxyméthyle (MOM) ou éthoxyméthyle (EOM) correspondants. Utilisant cette méthode, on a pu effectuer la
protection sélective d’alcools primaires et secondaires en présence de phénols et d’alcools tertiaires. On a effectué la
déprotection de ces éthers pour régénérer les alcools de départ en utilisant le même catalyseur, dans l’éthanol au reflux.
On a aussi trouvé que le même catalyseur permet de déprotéger sélectivement les éthers MOM et EOM en présence
d’éthers phénoliques ou tertiaires, d’éthers méthyliques et benzyliques, d’esters et d’éthers triméthylsilyles. Les avanta-
ges notables de ce protocole sont les rendements élevés, les courts temps de réaction, la facilité de l’extraction et le
fait que le catalyseur est non toxique, qu’il est de disponibilité et de maniement facile, respectueux de l’environnement
et réutilisable.
Mots-clés : méthoxyméthylation, éthoxyméthylation, protection, déprotection, acide hétéropolaire. Mohammadpoor-
Baltork et al. 840
Introduction
many advantages over the liquid acid catalysts, which are
harmless to the environment with respect to corrosiveness,
safety, and quantity of waste. Solid heteropoly acids have at-
tracted much attention in organic synthesis owing to easy
work-up procedure, easy filtration, and minimization of cost
and waste generation due to reuse and recycling of the cata-
lysts (2). A variety of organic reactions, such as alcohol
dehydration, acetylation, alkylation, isomerization, oxy-
dehydrogenation (1, 3), acylation (4), estrification (5),
synthesis of 1,4-dihydropyrimidones (6), oxidation of alkyl-
arenes (7), Friedel–Crafts acylation (8), Fries rearrangement
of arylesters (9), epoxidation of allylic alcohols (10), reac-
tions of oxiranes with carbonyl compounds (11), ring open-
ing of epoxides (12), conversion of THP ethers into acetates
(13), α-glycosidation (14), and preparation of oximes (15),
have been reported in the presence of heteropoly acid cata-
lysts.
Recently, green chemistry has received considerable im-
portance in organic synthesis. Due to environmental issues
affecting all societies, emphasize on the “green” aspects of
chemical processes will be appreciated. Thus, catalysts that
are eco-friendly and simply recycled in the reaction mixture
have attracted a considerable attention.
One important class of solid catalysts is heteropoly acids
(HPAs), having both redox and acid properties (1). Among
heteropoly acids, polytungstic acids are the most widely
used catalysts because of their high acid strengths, thermal
stability, and low reducibility. Heteropoly acid catalysts have
Received 31 December 2007. Accepted 19 March 2008.
Published on the NRC Research Press Web site at
canjchem.nrc.ca on 9 July 2008.
I. Mohammadpoor-Baltork,1 M. Moghadam,
S. Tangestaninejad, V. Mirkhani, and A. Mirjafari.
Department of Chemistry, Catalysis Division, University of
Isfahan, Isfahan 81746-73441, Iran.
To synthesize more complicated molecules, chemists have
developed satisfactory protective groups and also effective
methods for the formation and cleavage of these compounds.
The selective protection and deprotection of hydroxyl group
have occupied a unique position in organic synthesis be-
1Corresponding author (email: imbaltork@sci.ui.ac.ir).
Can. J. Chem. 86: 831–840 (2008)
doi:10.1139/V08-068
© 2008 NRC Canada

832
Can. J. Chem. Vol. 86, 2008
Scheme 1.
cause of the fundamental importance of hydroxyl groups and
their roles in the multi-step synthesis of complex natural
products (16). Transformation of hydroxyl groups to their
alkoxymethyl ethers is a commonly used protective process
for alcohols (17). These derivatives are frequently prepared
by the reactions of alcohols with a excess amount of formal-
dehyde dimethyl acetal (FDMA) or formaldehyde diethyl
acetal (FDEA) (18–25). Deprotection of these ethers to their
parent alcohols is also an important process in synthetic or-
ganic chemistry, and several methods and catalysts have
been reported for these transformations (23, 26–33). How-
ever, some of these methods suffer from drawbacks, such as
harsh reaction conditions, high reaction temperature, tedious
work-up procedures, long reaction times, and the use of ex-
pensive and toxic reagents. Consequently, introduction of
efficient and selective methods for the preparation of
alkoxymethyl ethers and their deprotection using inexpen-
sive, relatively non-toxic, easy handling, and environment-
friendly catalysts is still in demand.
Scheme 2.
In continuation of our studies on protection and
deprotection reactions (34), we now report H3PW12O40 as an
efficient, relatively non-toxic, recycable, and air-stable cata-
lyst for the preparation of methoxymethyl (MOM) and
ethoxymethyl (EOM) ethers at room temperature under sol-
vent-free conditions and also deprotection of these ethers in
a green solvent, ethanol, under reflux conditions (Scheme 1).
Scheme 3.
Results and discussion
First, we investigated the ability of H3PW12O40 in the
methoxymethylation and ethoxymethylation of benzyl alco-
hol with FDMA and FDEA, respectively. The results showed
that in the presence of 0.4 mol% of this catalyst, the MOM
and EOM ethers were obtained in high yields. Both protec-
tion reactions were carried out at room temperature and un-
der solvent-free conditions. Primary and secondary, benzylic
and saturated alcohols were efficiently converted to their
corresponding MOM- and EOM-ethers in high yields (Ta-
ble 1). Allylic alcohols, such as cinnamyl alcohol, were also
transformed to the corresponding MOM- and EOM-ethers
efficiently (Table 1, entry 20).
Under the same reaction conditions, phenols and tertiary
alcohols did not react even under reflux conditions, and the
starting materials remained intact after 24 h. Therefore, a set
of competitive reactions was conducted between primary or
secondary alcohols and phenols or tertiary alcohols (Table 2).
Also in compounds containing both benzylic and phenolic
hydroxyl groups, only benzylic hydroxyl groups were
converted to their corresponding ethers with excellent
chemoselectivity (Table 1, entries 7 and 10; Scheme 2). The
results indicated that the present protocol is potentially ap-
plicable for the chemoselective conversion of primary and
secondary alcohols to their MOM- and EOM-ethers in the
presence of phenols and tertiary alcohols.
The actual mechanism of these protection reactions is not
clear at present. However, a plausible explanation is that
FDMA or FDEA is first activated by catalyst to afford 1. Al-
cohol attacks 1 to give 2, which in turn converts to the final
product 3 and releases the catalyst for the next catalytic cy-
cle (Scheme 3).
The deprotection reactions of MOM- and EOM-ethers
with H3PW12O40 were also investigated (Scheme 1). We op-
timized the experimental conditions for the cleavage of
MOM- and EOM-ethers of benzyl alcohol, and the best re-
sults were achieved when 1 mmol of MOM- or EOM-ether
was treated with 1 mol% of catalyst in refluxing EtOH. Un-
der these conditions, various MOM- or EOM-ethers of pri-
mary and secondary benzylic, allylic, and saturated alcohols
were deprotected to their parent alcohols in high yields. The
results of deprotection reactions are illustrated in Table 3.
Also, a mechanism has been proposed for the deprotection
of these ethers (Scheme 4).
© 2008 NRC Canada

Mohammadpoor-Baltork et al.
Table 1. Preparation of MOM- and EOM-ethers from alcohols catalyzed by H3PW12O40 at
833
room temperature under solvent-free conditions.
To extend the scope and utility of this catalytic system, we
have performed several competitive deprotection reactions.
As can be seen, interesting selectivities were observed. Pri-
mary and secondary MOM- and EOM-ethers are deprotected
in the presence of phenolic and tertiary ones with high
selectivity (Table 4). Also, chemoselective deprotection of
these ethers in the presence of other hydroxyl protecting
groups such as benzyl and methyl ethers (Table 3, entries 7–
10), acetates and trimethylsilyl ethers (Table 5) is achieved
using this catalytic system. These selectivites can be consid-
ered as useful practical achievements in deprotection reac-
tions.
that the catalyst could be used several times without loss of
its activity.
In conclusion a mild, selective, and efficient protocol for
the preparation of MOM- and EOM-ethers at room tempera-
ture under solvent-free conditions and deprotection of these
ethers in refluxing EtOH in the presence of catalytic
amounts of H3PW12O40 has been established. The use of this
inexpensive, easily available, and reusable catalyst makes
this protocol practical, environment-friendly, and economi-
cally attractive. Mild reaction conditions, high product
yields, easy work-up procedures, and non-toxicity of the cat-
alyst are other noteworthy advantages of this method.
The reusability of the catalyst was examined using se-
quential reactions of benzyl alcohol with FDMA and FDEA
(Table 1, entry 1). At the end of the reaction, Et2O was
added, and the catalyst was separated by simple filtration.
The organic layer was washed with water, and the water was
evaporated to afford the remaining catalyst. The recovered
catalyst was reused for five cycles. The reactions were pre-
ceded smoothly with 88%–91% yields. The results indicated
Experimental
All materials were commercial reagent-grade, and alco-
hols, etherification reagents, and catalyst were purchased
from Merck chemical company. The products were identi-
fied by comparison of their spectra and physical data with
those of authentic samples. Melting points were determined
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Can. J. Chem. Vol. 86, 2008
Table 1 (concluded).
aIsolated yields.
b0.8 mol% of the catalyst was used.
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Mohammadpoor-Baltork et al.
Table 2. Competitive protection of alcohols and phenol catalyzed by H3PW12O40.
835
aPhenol and tertiary alcohol remained intact in the reactions mixture.
bIsolated yields.
1
using Stuart Scientific SMP2 apparatus. H NMR was re-
corded on a Bruker AC 500 MHz spectrometer. IR spectra
were recorded on a Shimadzu IR-435 spectrophotometer.
6H, CH(CH3)2), 1.27 (t, J = 6.68 Hz, 3H, OCH2CH3), 2.92
(m, 1H, CH(CH3)2), 3.67 (q, J = 7.09 Hz, 2H, OCH2CH3),
4.59 (s, 2H, OCH2O), 4.78 (s, 2H, ArCH2), 7.24 (d, J =
8.05 Hz, 2H, Ar), 7.31 (d, J = 8.03 Hz, 2H, Ar).
General procedure for the preparation of EOM- and
MOM-ethers
4-tert-Butyl–1-(ethoxymethoxy)methyl benzene (Table 1,
entry 3a)
To a solution of alcohol (1 mmol) in FDEA (5 mmol) or
FDMA (7 mmol), H3PW12O40 (0.004 mmol) was added and
stirred at room temperature for the appropriate time accord-
ing to Table 1. After completion of the reaction (TLC analy-
sis), the excess FDMA or FDEA was removed by rotary
evaporator. Et2O (20 mL) was added, and the mixture was
filtered. The organic layer was washed with water (10 mL)
and dried over anhyd. Na2SO4. Evaporation of the solvent
followed by chromatography on a short column of silica gel
(n-hexane – ethyl acetate, 4:1) afforded the pure product
(Table 1). In the case of solid materials, the products were
recrystallized form n-hexane – diethyl ether.
Oil. IR νmax (KBr, cm–1): 2900, 1360, 1090, 1030, 750,
1
700. H NMR (500 MHz, CDCl3) δH: 1.26 (t, J = 7.13 Hz,
3H, OCH2CH3), 1.34 (s, 9H, C(CH3)3), 3.67 (q, J = 7.05 Hz,
2H, OCH2CH3), 4.60 (s, 2H, OCH2O), 4.78 (s, 2H, ArCH2),
7.31 (d, J = 8.15 Hz, 2H, Ar), 7.40 (d, J = 8.21 Hz, 2H, Ar).
1-Benzyloxy-4-((ethoxymethoxy))methylbenzene (Table 1,
entry 4a)
Mp 69–72 °C. IR νmax (KBr, cm–1): 3000, 1190, 1080,
1
1040, 1020, 750, 740, 690. H NMR (500 MHz, CDCl3) δH:
1.26 (t, J = 6.99 Hz, 3H, OCH2CH3), 3.68 (q, J = 7.05 Hz,
2H, OCH2CH3), 4.47 (s, 2H OCH2O), 4.57 (s, 2H, ArCH2),
5.09 (s, 2H, PhCH2), 6.98 (d, J = 8.55 Hz, 4H, Ar), 7.29–
7.47 (m, 5H, Ar).
General procedure for the deprotection of MOM- and
EOM-ethers
A
mixture of alkoxymethyl ether (1 mmol) and
H3PW12O40 (0.01 mmol) in EtOH (8–10 mL) was stirred un-
der reflux conditions. After completion of the reaction (TLC
analysis), the solvent was evaporated, Et2O (20 mL) was
added and filtered. The organic layer was washed with water
(10 mL) and dried over anhyd. Na2SO4. The solvent was
evaporated and the crude product was purified by a short
column of silica gel (eluent: n-hexane – ethyl acetate, 4:1) to
afford the pure product (Table 3).
(Ethoxymethoxy)methylene dibenzene (Table 1, entry 5a)
Mp 90–93 °C. IR νmax (KBr, cm–1): 3000, 1210, 1080,
1
1010, 1000, 810. H NMR (500 MHz, CDCl3) δH: 1.11 (t,
J = 7.10 Hz, 3H, OCH2CH3), 3.41 (q, J = 7.06 Hz, 2H,
OCH2CH3), 4.42 (s, 2H, OCH2O), 5.43 (s, 1H, CH), 7.26–
7.40 (m, 12H, Ar).
1,4-Bis(ethoxymethoxy)methyl benzene (Table 1, entry 6a)
Selected physical and spectroscopic data
Mp 69–70 °C. IR νmax (KBr, cm–1): 2800, 1220, 1170,
(Ethoxymethoxy)methyl benzene (Table 1, entry 1a)
Oil. IR νmax (KBr, cm–1): 2800, 1380, 1160, 1100, 1040,
730, 680. 1H NMR (500 MHz, CDCl3) δH: 1.35 (t, J =
7.20 Hz, 3H, OCH2CH3), 3.70 (q, J = 7.10 Hz, 2H,
OCH2CH3), 4.73 (s, 2H, OCH2O), 4.92 (s, 2H, PhCH2),
7.37–7.43 (m, 5H, Ar).
1
1100, 1080, 1030, 810. H NMR (500 MHz, CDCl3) δH:
1.24 (t, J = 7.06 Hz, 6H, 2 × CH3), 3.65 (q, J = 7.07 Hz, 4H,
2 × CH2), 4.65 (s, 4H, 2 × OCH2O), 4.76 (s, 4H, 2 ×
ArCH2), 7.34 (s, 4H, Ar).
1,4-Bis(methoxymethoxy)methyl benzene (Table 1, entry 6b)
4-iso-Propyl–1-(ethoxymethoxy)methyl benzene (Table 1,
entry 2a)
Mp 68–70 °C. IR νmax (KBr, cm–1): 2800, 1210, 1080,
1
1010, 1000, 810. H NMR (500 MHz, CDCl3) δH: 4.55 (s,
Oil. IR νmax (KBr, cm–1): 3000, 1350, 1100, 1040, 800,
6H, 2 × CH3), 4.64 (s, 4H, OCH2O), 4.70 (s, 4H, 2 ×
1
790. H NMR (500 MHz, CDCl3) δH: 1.26 (d, J = 6.61 Hz,
ArCH2), 7.37 (s, 4H, Ar).
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Can. J. Chem. Vol. 86, 2008
Table 3. Deprotection of MOM- and EOM-ethers catalyzed by H3PW12O40 in refluxing ethanol.
Scheme 4.
2-(Ethoxymethoxy)methyl phenol (Table 1, entry 7a)
Oil. IR νmax (KBr, cm–1): 3400, 2800, 1330, 1280, 1100,
1
1050, 740, 680. H NMR (500 MHz, CDCl3) δH: 1.26 (t, J =
7.11 Hz, 3H, OCH2CH3), 3.56 (s, 2H, OCH2O), 4.66 (q, J =
7.03 Hz, 2H, OCH2CH3), 4.87 (s, 2H, ArCH2), 7.00–7.71
(m, 4H, Ar).
2-(Methoxymethoxy)methyl phenol (Table 1, entry 7b)
Oil. IR νmax (KBr, cm–1): 3400, 2800, 1310, 1270, 1100,
1
1050, 730, 700. H NMR (500 MHz, CDCl3) δH: 1.98 (s,
3H, OCH3), 2.02 (s, 2H, OCH2), 3.98 (s, 2H, ArCH2), 7.28–
7.34 (m, 4H, Ar).
3-Methoxy-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 8a)
Oil. IR νmax (KBr, cm–1): 2900, 1200, 1100, 1000, 800. 1H
NMR (500 MHz, CDCl3) δH: 1.27 (t, J = 6.40 Hz, 3H,
© 2008 NRC Canada

Mohammadpoor-Baltork et al.
Table 3 (concluded).
837
aIsolated yields.
b2 mol% of the catalyst was used.
OCH2CH3), 3.67 (q, J = 7.70 Hz, 2H, OCH2CH3), 3.82 (s,
3H, m-OCH3), 4.60 (s, 2H, OCH2O), 4.66 (s, 2H, ArCH2),
6.83–7.30 (m, 4H, Ar).
3H, OCH2CH3), 3.78 (q, J= 7.03 Hz, 2H, OCH2CH3), 3.82
(s, 3H, p-OCH3), 4.45 (s, 2H, OCH2O), 4.69 (s, 2H, ArCH2),
6.88 (d, J = 6.78 Hz, 2H, Ar), 7.28 (d, J = 7.07 Hz, 2H, Ar).
4-Methoxy-1-(Ethoxymethoxy)methyl benzene (Table 1,
entry 9a)
4-((Ethoxymethoxy)methyl)-2-methoxy phenol (Table 1,
entry 10a)
Oil. IR νmax (KBr, cm–1): 2800, 1240, 1170, 1100, 1030,
Mp 75–77 °C. IR νmax (KBr, cm–1): 3400, 2900, 1270,
1
1
810. H NMR (500 MHz, CDCl3) δH: 1.24 (t, J = 6.28 Hz,
1100, 1030, 790, 750. H NMR (500 MHz, CDCl3) δH: 1.22
© 2008 NRC Canada

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Can. J. Chem. Vol. 86, 2008
Table 4. Competitive deprotection of MOM- and EOM-ethers of
Table 5. Competitive deprotection of MOM- and EOM-ethers,
alcohols and phenol in the presence of H3PW12O40.
acetates, and trimethylsilyl ethers in the presence of H3PW12O40.
aIsolated yields.
2-Methoxy-4-((methoxymethoxy)methyl) phenol (Table 1,
entry 10b)
Mp 71–73 °C. IR νmax (KBr, cm–1): 3300, 2900, 1200,
1
1000, 1060, 820, 790. H NMR (500 MHz, CDCl3) δH: 4.12
(s, 3H, OCH3), 4.56 (s, 2H, OCH2O), 4.66 (s, 3H, o-OCH3),
4.84 (s, 2H, ArCH2), 7.26–7.36 (m, 3H, Ar).
2-Chloro-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 11a)
Mp 61 °C. IR νmax (KBr, cm–1): 2800, 1250, 1120, 1050,
1
1020, 840, 740. H NMR (500 MHz, CDCl3) δH: 1.25 (t, J =
7.07 Hz, 3H, OCH2CH3), 3.67 (q, J = 7.08 Hz, 2H,
OCH2CH3), 4.71 (s, 2H, OCH2O), 4.81 (s, 2H, ArCH2),
7.23–7.48 (m, 4H, Ar).
aIsolated yields.
4-Choloro-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 12a)
Mp 69 °C. IR νmax (KBr, cm–1): 2900, 1320, 1280, 1100,
840, 760. 1H NMR (500 MHz, CDCl3) δH: 1.18 (t, J =
7.05 Hz, 3H, OCH2CH3), 3.55 (q, J = 7.04 Hz, 2H,
OCH2CH3), 4.62 (s, 2H, OCH2O), 4.86 (s, 2H, ArCH2), 7.29
(d, J = 7.44 Hz, 2H, Ar), 7.34 (d, J = 6.42 Hz, 2H, Ar).
(t, J = 7.11 Hz, 3H, OCH2CH3), 3.72 (s, 3H, o-OCH3), 3.75
(q, J = 7.07 Hz, 2H, OCH2CH3), 5.31 (s, 2H, OCH2O), 5.44
(s, 2H, ArCH2), 6.43–7.26 (m, 3H, Ar).
© 2008 NRC Canada

Mohammadpoor-Baltork et al.
839
2,4-Dichloro-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 13a)
1-(Ethoxymethoxy)ethyl benzene (Table 1, entry 21a)
Oil. IR
(KBr, cm–1): 2800, 1420, 1100, 1030, 720,
680. H NMR (500 MHz, CDCl3) δH: 1.23 (t, J = 7.04 Hz,
3H, OCH2CH3), 1.42 (d, J = 10.29 Hz, 3H, PhCHCH3), 2.05
(s, 2H, OCH2O), 3.49 (q, J = 7.01 Hz, 2H, OCH2CH3), 4.13
(q, J = 7.01 Hz, 1H, PhCH), 7.28–7.35 (m, 5H, Ar).
νmax
1
Mp 59–60 °C. IR νmax (KBr, cm–1): 2800, 1340, 1160,
1
1100, 1050, 820, 800, 730. H NMR (500 MHz, CDCl3) δH:
1.21 (t, J= 7.00 Hz, 3H, OCH2CH3), 3.60 (q, J = 7.01 Hz,
2H, OCH2CH3), 4.76 (s, 2H, OCH2O), 4.92 (s, 2H, ArCH2),
7.30 (s, 1H, Ar), 7.50 (d, J = 8.62 Hz, 1H, Ar), 8.20 (d, J =
8.90 Hz, 1H, Ar).
2-(Ethoxymethoxy)cycloheptane (Table 1, entry 22a)
Oil. IR νmax (KBr, cm–1): 2900, 1370, 1090, 1030. 1H
NMR (500 MHz, CDCl3) δH: 1.19 (t, J = 7.65 Hz, 3H,
OCH2CH3), 1.49–1.88 (m, 12H, –(CH2)6–), 3.57 (q, J =
7.1 Hz, 2H, OCH2CH3), 3.69–3.73 (m, 1H, OCH), 4.66 (s,
2H, OCH2O).
2-Bromo-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 14a)
Mp 60–62 °C. IR νmax (KBr, cm–1): 2800, 1360, 1100,
1
1050, 1020, 740. H NMR (500 MHz, CDCl3) δH: 1.25 (t,
J = 7.05 Hz, 3H, OCH2CH3), 3.68 (q, J = 7.10 Hz, 2H,
OCH2CH3), 4.76 (s, 2H, OCH2O), 4.82 (s, 2H, ArCH2),
7.15–7.55 (m, 4H, Ar).
2-(Ethoxymethoxy)methyl adamentane (Table 1, entry 23a)
Mp 270–274 °C. IR νmax (KBr, cm–1): 2800, 1360, 1240,
1
1100, 1040. H NMR (500 MHz, CDCl3) δH: 1.21 (t, J =
11.56 Hz, 3H, OCH2CH3), 1.49–2.06 (m, 14H, adamentyl),
3.68 (q, J = 8.55 Hz, 2H, OCH2CH3), 3.78 (d, J= 12.27 Hz,
1H, OCH), 4.82 (s, 2H, OCH2O).
4-Bromo-1-(ethoxymethoxy)methyl benzene (Table 1,
entry 15a)
Mp 61–64 °C. IR νmax (KBr, cm–1): 2800, 1400, 1160,
1
1060, 1010, 790. H NMR (500 MHz, CDCl3) δH: 1.27 (t,
2-(Ethoxymethoxy)heptane (Table 1, entry 24a)
Oil. IR νmax (KBr, cm–1): 2800, 1380, 1240, 1100, 1040,
J = 5.90 Hz, 3H, OCH2CH3), 3.63 (q, J = 5.84 Hz, 2H,
OCH2CH3), 4.56 (s, 2H, OCH2O), 4.76 (s, 2H, ArCH2), 7.22
(d, J = 8.38 Hz, 2H, Ar), 7.48 (d, J = 6.29 Hz, 2H, Ar).
1
820. H NMR (500 MHz, CDCl3) δH: 0.87 (t, J= 7.06 Hz,
3H, CH3), 1.20 (t, J = 7.10 Hz, 3H, OCH2CH3), 1.24–1.57
(m, 10H, –(CH2)5–), 3.51 (t, J = 6.66 Hz, 2H, CH2O), 3.58
(q, J = 7.09 Hz, 2H, OCH2CH3), 4.65 (s, 2H, OCH2O).
2-Nitro-1-(ethoxymethoxy)methyl benzene (Table 1, entry
16a)
Mp 71–73 °C. IR νmax (KBr, cm–1): 2800, 1500, 1320,
2-(Ethoxymethoxy)octane (Table 1, entry 25a)
1
Oil. IR νmax (KBr, cm–1): 2800, 1380, 1240, 1100, 1040,
1120, 1100, 1050, 830, 740. H NMR (500 MHz, CDCl3)
1
δH: 1.30 (3H, t, J= 7.07 Hz, OCH2CH3), 3.70 (2H, q, J=
7.07 Hz, OCH2CH3), 4.75 (2H, s, OCH2O), 4.82 (2H, s,
ArCH2), 7.51 (t, J = 8.39 Hz, 2H, Ar), 8.19 (d, J = 8.56 Hz,
2H, Ar).
820. H NMR (500 MHz, CDCl3) δH: 0.88 (t, J = 7.39 Hz,
3H, CH3), 1.24 (t, J = 7.16 Hz, 3H, OCH2CH3), 1.26–1.49
(m, 12H, –(CH2)6–), 3.41 (t, J = 5.49 Hz, 2H, CH2O), 3.60
(q, J = 7.06 Hz, 2H, OCH2CH3), 4.67 (s, 2H, OCH2O).
3-Nitro-1-(ethoxymethoxy)methyl benzene (Table 1, entry
17a)
Acknowledgements
Oil. IR νmax (KBr, cm–1): 2800, 1500, 1120, 1100, 1030,
820, 730. 1H NMR (500 MHz, CDCl3) δH: 1.24 (t, J =
7.09 Hz, 3H, OCH2CH3), 3.65 (q, J = 7.08 Hz, 2H,
OCH2CH3), 4.59 (s, 2H, OCH2O), 4.77 (s, 2H, ArCH2), 6.84
(d, J = 8.26 Hz, 1H, Ar), 6.92 (d, J = 7.62 Hz, 2H, Ar), 7.26
(t, J = 7.90 Hz, 1H, Ar).
We are thankful to the Centre of Excellence of Chemistry
of University of Isfahan (CECUI) and Office of the Graduate
Studies for financial support of this work.
References
1. (a) M.T. Pope. Heteropoly and isopoly oxometalates. Springer-
Velag, Berlin, Germany. 1993; (b) N. Mizuno and M. Misono.
Chem. Rev. 98, 199 (1998); (c) H. Firouzabadi and A.A.
Jafari. J. Iran. Chem. Soc. 2, 85 (2005).
4-Nitro-1-(ethoxymethoxy)methyl benzene (Table 1, entry
18a)
Mp 88–90 °C. IR νmax (KBr, cm–1): 2800, 1500, 1320,
1
2. M.A. Schwenger, H. Van Bekkum, and N. Munck. Appl. Catal.
1160, 1100, 1040, 840, 790. H NMR (500 MHz, CDCl3)
74, 191 (1991).
δH: 1.30 (t, J = 7.08 Hz, 3H, OCH2CH3), 3.70 (q, J =
7.06 Hz, 2H, OCH2CH3), 4.59 (s, 2H, OCH2O), 4.83 (s, 2H,
ArCH2), 7.24 (d, J = 8.2 Hz, 2H, Ar), 7.50 (d, J = 8.55 Hz,
2H, Ar).
3. N. Mizuno and M. Misono. J. Mol. Catal. A: Chem. 86, 319
(1994).
4. V. Mirkhani, S. Tangestaninejad, M. Moghadam, B. Yadollahi,
and L. Alipanah. Monatsh. Chem. 135, 1257 (2004).
5. E. Rafiee, S. Tangestaninejad, M.H. Habibi, and V. Mirkhani.
Bull. Korean Chem. Soc. 25, 599 (2004).
2-(Ethoxymethoxy)ethyl benzene (Table 1, entry 19a)
Oil. IR νmax (KBr, cm–1): 2800, 1380, 1110, 1060, 1020,
740, 690. 1H NMR (500 MHz, CDCl3) δH: 1.22 (t, J =
7.05 Hz, 3H, OCH2CH3), 2.89 (t, J = 7.02 Hz, 2H, PhCH2),
3.59 (q, J = 7.03 Hz, 2H, OCH2CH3), 3.78 (t, J = 7.02 Hz,
2H, PhCH2CH2O), 4.67 (s, 2H, OCH2O), 7.17–7.31 (m, 5H,
Ar).
6. R. Fazaeli, S. Tangestaninejad, H. Aliyan, and M. Moghadam.
Appl. Catal. A: General, 309, 44 (2006).
7. A.M. Khenkin and R. Neurnann. J. Am. Chem. Soc. 124, 4198
(2002).
8. J. Kaur, K. Griffin, B. Harrison, and I.V. Kozhevnikov. J. Catal.
208, 448 (2002).
© 2008 NRC Canada

840
9. E.F. Kozhenikova, E. Rafiee, and I.V. Kozhenikov. Appl.
Catal. A: Chem. 260, 25 (2004).
10. Y.M.A. Yamada, H. Tabata, H. Takahashi, and S. Ikegami.
Synlett, 2031 (2002).
11. V. Mirkhani, S. Tangestaninejad, B. Yadollahi, and L.
Alipanah. Catal. Lett. 91, 129 (2003).
Can. J. Chem. Vol. 86, 2008
24. B. Karimi and L. Ma’mani. Tetrahedron Lett. 44, 6051 (2003).
25. (a) K. Niknam, M.A. Zolfigol, A. Khorramabadi-Zad, R. Zare,
and M. Shayegh. Catal. Commun. 7, 494 (2006); (b) M.A.
Zolfigol and M. Shiri. Mendeleev Commun. 165 (2005); (c) K.
Niknam, M.A. Zolfigol, M. Shayegh, and R. Zare. J. Chinese
Chem. Soc. 54, 1067 (2007).
12. (a) S. Tangestaninejad, M. Moghadam, V. Mirkhani, B.
Yadollahi, and S.M.R. Mirmohmmadi. Monatsh. Chem. 137,
235 (2006); (b) V. Mirkhani, S. Tangestaninejad, B. Yadollahi,
and L. Alipanah. Tetrahedron, 59, 8213 (2003).
13. E. Rafiee, S. Tangestaninejad, M.H. Habibi, I. Mohammadpoor-
Baltork, and V. Mirkhani. Russian J. Org. Chem. 41, 393
(2005).
26. B.F. Marcune, S. Karady, U.H. Dolling, and T. Novak. J. Org.
Chem. 64, 2446 (1999).
27. D.A. Goff, R.N. Harris, J.C. Bottaro, and C.D. Bedford. J.
Org. Chem. 51, 4711 (1986).
28. T.R. Boehlow, J.J. Harburn, and C.D. Spilling. J. Org. Chem.
66, 3111 (2001).
29. E.J. Corey, D.H. Hua, and S.P. Seitz. Tetrahedron Lett. 25, 3
(1984).
14. E. Rafiee, S. Tangestaninejad, M.H. Habibi, and V. Mirkhani.
Bioorg. Med. Chem. Lett. 14, 3611 (2004).
15. R. Fazaeli, S. Tangestaninejad, and H. Aliyan. Catal.
Commun. 8, 205 (2007).
30. A.S.-Y. Lee, Y.-J. Hu, and S.-F. Chu. Tetrahedron, 57, 2121
(2001).
31. J.P. Deville and V. Behar. J. Org. Chem. 66, 4097 (2001).
32. C. Ramesh, N. Ravindranath, and B. Das. J. Org. Chem. 68,
7101 (2003).
16. (a) M. Schelhaas and H. Waldmann. Angew. Chem., Int. Ed.
Engl. 35, 2056 (1996); (b) C.J. Salmon, E.G. Mata, and O.A.
Marscaretti. Tetrahedron, 49, 3691 (1993).
17. (a) T.W. Greene and P.G.M. Wuts. Protective groups in organic
synthesis. Wiley, New York. 1991. Chap. 2. p. 5; (b) P.J.
Kocienski. Protecting gourps. Georg Thieme, New York. 1994.
18. G.A. Olah, A. Husain, B.G.B. Gupta, S.C. Narang. Synthesis,
896 (1983).
19. M.L. Kantam and P.L. Santhi. Synlett, 429 (1993).
20. R.L. Danheiser, K.R. Romines, H. Koyama, S.K. Gee, C.R.
Johnson, and J. R. Medich. Org. Synth. 71, 133 (1992).
21. B.P. Bandgar, C.T. Hajare, and P.P. Wadgaonkar. J. Chem. Res.
(S), 90 (1996).
33. J.M. Keith. Tetrahedron Lett. 45, 2739 (2004).
34. (a) I. Mohammadpoor-Baltork and H. Aliyan. J. Chem. Res.
(S) 272 (1999); (b) I. Mohammadpoor-Baltork and H. Aliyan.
Synth. Commun. 29, 2741 (1999); (c) I. Mohammadpoor-
Baltork and H. Aliyan. Indian J. Chem. 38B, 1223 (1999);
(d) I. Mohammadpoor-Baltork, M.K. Amini, and S. Farshipoor.
Bull. Chem. Soc. Jpn. 73, 2775 (2000); (e) H. Firouzabadi, I.
Mohammadpoor-Baltork, and S. Kolagar. Synth. Commun. 31,
905 (2001); ( f ) I. Mohammadpoor-Baltork, B. Kharamesh,
and S. Kolagar. Synth. Commun. 32, 1633 (2002); (g) A.
Bamoniri, M.A. Zolfigol, I. Mohammadpoor-Baltork, and B.F.
Mirjalili. J. Iranian Chem. Soc. 3, 85 (2006); (h) I.
Mohammadpoor-Baltork, M.M. Khodaei, and H. Ahankar.
Lett. Org. Chem. 3, 768 (2006).
22. T.-S. Jin, T.-S. Li, and Y.-T. Gao. Synth. Commun. 28, 837
(1998).
23. G.V.M. Sharma, K.L. Reddy, P.S. Lakshmi, and P.R. Krishna.
Tetrahedron Lett. 45, 9229 (2004).
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