New method for the synthesis of benzyl alkyl ethers mediated by FeSO 4

Article abstract of DOI:10.1080/00397911003642674

The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using FeSO₄ as a recoverable and reusable mediator has been described without use of base and cosolvent under mild conditions.

Full text of DOI:10.1080/00397911003642674

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New Method for the Synthesis of Benzyl
Alkyl Ethers Mediated by FeSO4
Girdhar Joshi a & Subbarayappa Adimurthy a
a Central Salt and Marine Chemicals Research Institute, Council of
Scientific and Industrial Research (CSIR) , Bhavnagar, Gujarat, India
Published online: 31 Jan 2011.
To cite this article: Girdhar Joshi & Subbarayappa Adimurthy (2011) New Method for the Synthesis of
Benzyl Alkyl Ethers Mediated by FeSO4 , Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 41:5, 720-728, DOI: 10.1080/00397911003642674
To link to this article: http://dx.doi.org/10.1080/00397911003642674
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Synthetic Communications1, 41: 720–728, 2011
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911003642674
NEW METHOD FOR THE SYNTHESIS OF BENZYL
ALKYL ETHERS MEDIATED BY FeSO4
Girdhar Joshi and Subbarayappa Adimurthy
Central Salt and Marine Chemicals Research Institute, Council of Scientific
and Industrial Research (CSIR), Bhavnagar, Gujarat, India
Abstract The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using
FeSO4 as a recoverable and reusable mediator has been described without use of base
and cosolvent under mild conditions.
Keywords Alcohols; benzyl alkyl ethers; benzyl bromides; FeSO4
INTRODUCTION
Benzyl and substituted benzyl ethers are the most versatile protecting
groups.[1,2] The synthesis of benzyl alkyl ethers include Williamson ether synthesis
under basic or acidic conditions using trichloroacetimidates[3] and benzyloxypyridi-
nium triflates with alcohol in the presence of additives.[4] The literature survey
evinces that only a few reports have been published for the synthesis of benzyl ethers
without base and additives.[5]
Herein, we report the synthesis of benzyl alkyl ethers from benzyl bromides
and alcohols using ferrous sulfate as a mediator without base and cosolvent
(Scheme 1).
Received September 17, 2009.
Address correspondence to Subbarayappa Adimurthy, Central Salt and Marine Chemicals
Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364
002, Gujarat, India. E-mail: sadimurthy@yahoo.com
720

SYNTHESIS OF BENZYL ALKYL ETHERS
721
Scheme 1. Synthesis of benzyl alkyl ethers.
RESULTS AND DISCUSSION
Initially, benzyl bromide was refluxed in methanol with 0.5 equivalents of
FeSO4 (Scheme 1). After 12 h, moderate yield (22%) of the desired product was
obtained (entry 1, Table 1). When FeSO4 was increased to 1 equivalent, complete
conversion with 100% selectivity was observed (entry 2, Table 1) in 12 h. This
suggests that it is essential to use 1 equivalent of FeSO4 to achieve complete conver-
sion and selectivity. Most of the following experiments were carried out with 1
Table 1. Screening of conditions for benzyl alkyl ether synthesis
Entry
ROH 2
FeSO4 (equiv.)
Yield 3 (%)a
1
2
3
4
CH3OH
CH3OH
CH3OH
0.5
1.0
1.5
1.0
22
100 (92)
100
100 (91)
CH3CH2OH
5
1.0
1.0
100 (87)
98
6b
7
1.0
1.0
99 (92)
97
8b
9b
1.0
87
Note. Conditions: 1a (3.0 mmol), 2 (5.0 mL), reflux, 12 h.
aGC yields based on starting benzyl bromide; numbers in parantheses are isolated yields.
bTemperature at 110 ꢀC.

722
G. JOSHI AND S. ADIMURTHY
Table 2. Syntheses of various benzyl alkyl ethers
Entry
1
4
ROH 2
5
Yield (%)a
70
4a
MeOH
2
3
4
4a
4a
4a
EtOH
PrOH
66
82
98b
5
4a
84b
6
7
8
4b
4b
4b
MeOH
EtOH
PrOH
90
87
92
9
10
11
4c
4c
4c
MeOH
EtOH
PrOH
62
68
69
(Continued )

SYNTHESIS OF BENZYL ALKYL ETHERS
723
Table 2. Continued
Entry
12
4
ROH 2
5
Yield (%)a
87
4d
MeOH
13
14
4d
4d
84
66b
aIsolated yields under the optimized conditions of Table 1.
bGC yields.
equivalent of FeSO4 during a period of 12 h. Ethanol and propanol reacted smoothly
with benzyl bromide and offered the products benzyl ethyl ether (Table 1, entry 4)
and benzyl propyl ether (Table 1, entry 5) in 91% and 87% isolated yields, respect-
ively. The long-chain alcohols such as n-hexanol gave 98% yield (GC) of n-hexyl
benzyl ether (entry 6). Secondary alcohols such as isopropyl alcohol and cyclohexa-
nol were also easy to react with benzyl bromide under the same conditions to provide
Table 3. Etherification of a,a0-dibromo-p=o xylenes with different alcohols
Entry
1
Substrate
Alcohol
Product
Isolated yield (%)
MeOH
80
2
3
4
5
6
EtOH
PrOH
MeOH
EtOH
PrOH
80
84
91
90
88

724
G. JOSHI AND S. ADIMURTHY
excellent yields of bezyl isopropy ether (Table 1, entry 7) and benzyl cyclohexyl ether
(Table 1, entry 8) in 99% (92% isolated) and 97% yields (by gas chromatography,
GC) respectively. Even bezyl alcohol gave dibenzyl ether in 87% (GC) yield
(Table 1, entry 9).
As can be justified by the results of Table 1, various primary and secondary
alcohols reacted with benzylbromide neatly to provide subsequent benzyl ether in
excellent yields. Therefore, most of the following experiments with various benzyl
bromides were carried out with these alcohols, and results are summarized in
Table 2. The electron-withdrawing and electron-releasing groups present in the
phenyl ring participated in the reaction.
Under these optimized conditions, we further extended the scope of the present
method for synthesis of a,a0-dialky benzyl ethers,[1d] and results are summarized in
Table 3.
After the fresh reaction, FeSO4 was filtered, washed with methanol, and dried,
and it was reused for subsequent three runs with comparative yields of product
(benzyl methyl ether in 92%, 88%, and 84%, respectively).
EXPERIMENTAL
1H and 13C NMR spectra were recorded on a spectrometer operating at
500 MHz and 125 MHz, respectively, in CDCl3 unless otherwise stated. Chemical
shifts are reported in parts per million (ppm) relative to the appropriate standard,
tetramethylsilane (TMS), for 1H and 13C NMR spectra. Fourier-transform–infrared
(FT-IR) spectra were recorded on a Perkin-Elmer GX-2000 spectrometer. GC was
recorded on a Thermo Trace GC Ultra instrument using a HP-5 column. Column
chromatography for purification was carried out on silica gel (100–200 mesh). Melt-
ing points were obtained on a melting-point apparatus with open capillary tubes and
are uncorrected. Analytical thin-layer chromatography (TLC) was performed on an
Aluchrosep silica gel 60=UV254 plate. Liquid chromatography mass spectra
(LCMS) of samples were recorded on micromass Q-TOF Micro electrospray ioniza-
tion (ESI) þve mode.
General Procedure for the Synthesis of Alkylbenzylethers:
Representative Procedure for (Methoxymethyl)benzene (Entry 2,
Table 1)
A mixture of benzyl bromide (0.51 g, 3.0 mmol) and FeSO4 (3.0 mmol) were
refluxed in methanol (5.0 mL) at 75 ꢀC for a period of 12 h; progress of the reaction
was monitored by thin-layer chromatography (TLC). After complete disappearance
of benzyl bromide, the reaction mixture was cooled to room temperature (25 ꢀC),
FeSO4 was removed by filtration, and the residue was washed with 10 mL of cold
methanol. The methanol was stripped out, and the residue left out was purified by col-
umn chromatography to obtain the pure product in 92% yield. IR nmax (neat) ¼ 2925,
2853, 1459, 1262, 1028, 804, 659 cmꢁ1. 1H NMR (CDCl3): d (ppm) ¼ 7.2 (m, 5H), 4.4
(s, 2H), 4.3 (s, 2H), 3.3 (s, 3H). 13C NMR (CDCl3): d (ppm) ¼ 138.1 (Quat C), 128.4,
127.7, 74.7, 58.1. MS (ESI) (C8H10O) ¼ cal. 122.08 [Mþ], obsd. 122.31.

SYNTHESIS OF BENZYL ALKYL ETHERS
725
Selected Data
(Ethoxymethyl)benzene (Entry 4, Table 1). IR nmax (neat) ¼ 2962, 2927,
2858, 2355, 1451, 1261, 1098, 1032, 866, 805, 670 cmꢁ1. 1H NMR (CDCl3): d (ppm) ¼
7.2 (m, 5H), 4.4 (s, 2H), 3.4 (q, J ¼ 21.0, 14.0, 7.0 Hz, 2H), 1.1 (t, J ¼ 14.0, 7.0 Hz, 3H).
13C NMR (CDCl3): d (ppm) ¼ 138.5 (Quat C), 128.3, 127.7, 127.5, 72.7, 65.7, 15.2.
MS (ESI) (C9H12O) ¼ cal. 159.09 [Mþ þ Na], obsd. 159.61.
(Propoxymethyl)benzene (Entry 5, Table 1). IR nmax (neat) ¼ 2962, 2930,
1
2858, 1455, 1364, 1104, 1032, 738, 698 cmꢁ1. H NMR (CDCl3): d (ppm) ¼ 7.3 (m,
5H), 4.4 (s, 2H), 3.4 (t, J ¼ 13.5, 6.5 Hz, 2H), 1.6 (m, 2H), 0.9 (t, J ¼ 15.0, 5.0 Hz,
3H). 13C NMR (CDCl3): d (ppm) ¼ 138.7 (Quat C), 128.3, 127.6, 127.5, 72.8, 72.1,
23.0, 10.7. MS (ESI) (C10H14O) ¼ cal. 182.10 [MþþMeOH], obsd. 183.70.
(Isopropoxymethyl)benzene (Entry 7, Table 1). IR nmax (neat) ¼ 2967,
1
2927, 2858, 1455, 1375, 1265, 1119, 809, 739, 699, 618 cmꢁ1. H NMR (CDCl3): d
(ppm) ¼ 7.2 (s, 5H), 4.4 (s, 2H), 3.6 (m, 1H), 1.2 (d, J ¼ 6 Hz, 6H). 13C NMR
(CDCl3): d (ppm) ¼ 139.1 (Quat C), 128.3, 127.6, 127.4, 70.9, 70.0, 22.1. MS (ESI)
(C10H14O) ¼ cal. 150.10 [Mþ], obsd. 150.50.
1-Nitro-4-(methoxymethyl)benzene (Entry 1, Table 2). IR nmax (neat) ¼
2928, 1605, 1522, 1348, 1200, 1104, 848, 740 cmꢁ1. 1H NMR (CDCl3): d (ppm) ¼ 8.1
(d, J ¼ 8.5 Hz, 2H), 7.5 (d, J ¼ 9.0 Hz, 2 H), 4.5 (s, 2H), 3.4 (s, 3H). 13C NMR
(CDCl3): d (ppm) ¼ 147.2 (Quat-C), 146.0 (Quat-C), 127.6, 123.4, 73.2, 58.5. MS
(ESI) (C8H9NO3) ¼ cal.167.05 [Mþ], obsd. 168.10.
1-Nitro-4-(ethoxymethyl)benzene (Entry 2, Table 2). IR nmax (neat) ¼
1
2924, 2868, 1527, 1346, 1107, 859, 740 cmꢁ1. H NMR (CDCl3): d (ppm) ¼ 8.1 (d,
J ¼ 8.5 Hz, 2 H), 7.5 (d, J ¼ 8.0 Hz, 2 H), 4.6 (s, 2H), 3.6 (q, J ¼ 21.0, 14.0, 7.0 Hz,
2H), 1.2 (t, J ¼ 14.0, 7.0 Hz, 3H). 13C NMR (CDCl3): d (ppm) ¼ 147.2 (Quat C),
146.4 (Quat C), 127.6, 123.5, 71.3, 66.4, 15.1. MS (ESI) (C9H11NO3) ¼ cal. 181.50
[Mþ], obsd. 182.59.
1-Nitro-4-(propoxymethyl)benzene (Entry 3, Table 2). IR nmax (neat) ¼
2929, 2873, 1521, 1346, 1099, 1051, 844, 740, 601 cmꢁ1 1H NMR (CDCl3): d
.
(ppm) ¼ 8.1 (d, J ¼ 8.5 Hz, 2 H), 7.5 (d, J ¼ 8.0 Hz, 2 H), 4.6 (s 2H), 3.5 (t,
J ¼ 13.0, 6.5 Hz, 2H), 1.6 (d, J ¼ 7.5 Hz, 2H), 0.9 (t, J ¼ 15.0, 7.5 Hz, 3H). 13C
NMR (CDCl3): d (ppm) ¼ 146.6 (Quat C), 129.9 (Quat C), 127.5, 123.4, 71.4,
22.9, 10.5. MS (ESI) (C10H13NO3) ¼ cal. 195.09 [Mþ], obsd. 195.44.
1-Chloro-4-(methoxymethyl)benzene (Entry 6, Table 2). IR nmax (neat) ¼
1
2927, 2869, 1599, 1491, 1406, 1378, 1196, 1093, 1016, 807, 672 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.3 (d, J ¼ 8.5 Hz, 2H), 7.2 (d, J ¼ 8.0 Hz, 2H), 4.3 (s, 2H), 3.3
(s, 3H). 13C NMR (CDCl3): d (ppm) ¼ 136.7 (Quat C), 133.3 (Quat C), 128.9,
128.5, 58.1. MS (ESI) (C8H9ClO) ¼ cal. 156.03 [Mþ], obsd. 157.13.
1-Chloro-4-(ethoxymethyl)benzene (Entry 7, Table 2). IR nmax (neat) ¼
2977, 2863, 1597, 1490, 1093, 1017 806, 666, 524 cmꢁ1 1H NMR (CDCl3): d
.
(ppm) ¼ 7.2 (d, J ¼ 8.0 Hz, 2H), 7.1 (d, J ¼ 8.5 Hz, 2H), 4.3 (s, 1H), 3.4 (q,
J ¼ 21.0, 14.0, 7.0 Hz, 2H), 1.5 (t, J ¼ 14.0, 7.0 Hz, 3H). 13C NMR (CDCl3): d

726
G. JOSHI AND S. ADIMURTHY
(ppm) ¼ 137.1 (Quat C), 133.2 (Quat C), 128.9, 128.5, 71.9, 65.8, 15.2. MS (ESI)
(C9H11ClO) ¼ cal. 203.04 [Mþ þ Na], obsd. 203.89.
1-Chloro-4-(propoxymethyl)benzene (Entry 8, Table 2). IR nmax (neat) ¼
1
2962, 2934, 2864, 1488, 1362, 1100, 1015, 810, 482, cmꢁ1. H NMR (CDCl3): d
(ppm) ¼ 7.2 (d, J ¼ 8.5 Hz, 2H), 7.2 (d, J ¼ 8.5 Hz, 2H), 4.4 (s, 2H), 3.4 (s, 2H), 1.6
(q, J ¼ 21.0, 14.0, 7.0 Hz, 2H), 0.9 (t, J ¼ 15.0, 7.5 Hz 3H). 13C NMR (CDCl3): d
(ppm) ¼ 137.4 (Quat C), 133.2 (Quat C), 129.0, 128.6, 72.3, 72.1, 23.1, 10.7. MS
(ESI) (C10H13ClO) ¼ cal. 184.06 [Mþ], obsd. 185.01.
1-Bromo-3-(methoxymethyl)benzene (Entry 9, Table 2). IR nmax (neat) ¼
1
2986, 2927, 2823, 1572, 1470, 1426, 1377, 1198, 1106, 968, 779, 690 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.4 (s, 1H), 7.4 (d, J ¼ 7.5 Hz, 2 H), 7.2 (d, J ¼ 7.5 Hz, 2H), 4.3 (s,
2H), 7.1 (t, J ¼ 15.0, 7.5 Hz, 2H), 3.2 (s, 3H). 13C NMR (CDCl3): d (ppm) ¼ 140.6
(Quat C), 130.6, 129.9, 127.6, 126.0, 122.5 (Quat C), 73.7, 58.3. MS (ESI)
(C8H9OBr) ¼ cal. 231.9 [Mþ þ MeOH], obsd. 231.77.
1-Bromo-3-(ethoxymethyl)benzene (Entry 10, Table 2). IR nmax (neat) ¼
1
2976, 2928, 2863, 2354, 1572, 1472, 1352, 1201, 1113, 777, 682 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.4 (s, 1H), 7.3 (d, J ¼ 7.5 Hz, 2H), 7.2 (d, J ¼ 7.0 Hz, 2H), 7.1
(d, J ¼ 7.5 Hz, 2H), 4.3 (s, 2H), 3.4 (q, J ¼ 20.5, 13.5, 6.5 Hz, 2H), 1.1 (t, J ¼ 14.0,
7.0 Hz, 3H). 13C NMR (CDCl3): d (ppm) ¼ 141.0 (Quat C), 130.5, 129.9, 127.6,
126.0, 122.5 (Quat C), 71.9, 66.0, 15.2. MS (ESI) (C9H11OBr) ¼ cal. 246.00
[Mþ þ MeOH], obsd. 246.53.
1-Bromo-3-(propoxymethyl)benzene (Entry 11, Table 2). IR nmax (neat) ¼
1
2963, 2932, 2867, 2335, 1572, 1470, 1357, 1200, 1109, 778, 687 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.4 (s, 1H), 7.3 (d, J ¼ 7.5 Hz, 2H), 7.2 (d, J ¼ 7.5 Hz, 2H), 7.1
(d, J ¼ 8.0 Hz, 2H), 4.4 (s, 2H), 3.4 (t, J ¼ 13.0, 6.5 Hz, 2H), 1.6 (q, J ¼ 21.5, 14.5,
7.5 Hz, 2H), 0.9 (t, J ¼ 15.0, 7.5 Hz, 3H). 13C NMR (CDCl3): d (ppm) ¼ 141.2 (Quat
C), 134.2, 130.5, 129.9, 127.5, 125.9, 122.5 (Quat C), 72.3, 71.9, 22.9, 10.6. MS (ESI)
(C10H13OBr) ¼ cal. 260.01 [Mþ þ MeOH], obsd. 260.57.
1-(Ethoxymethyl)-4-methoxy-benzene (Entry 12, Table 2). IR nmax
1
(neat) ¼ 2930, 2858, 1612, 1513, 1458, 1248, 1173, 1100, 1035, 817 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.1 (d, J ¼ 8.5 Hz, 2H), 6.7 (d, J ¼ 8.5 Hz, 2H), 4.3 (s, 2H), 3.6
(s, 3H), 3.4 (d, J ¼ 7.0 Hz, 2H), 1.1 (t, J ¼ 14.0, 7.0 Hz, 3H). 13C NMR (CDCl3): d
(ppm) ¼ 159.1 (Quat C), 129.7 (Quat C), 126.3, 113.7, 72.4, 65.4, 55.2, 15.2. MS
(ESI) (C10H14O2) ¼ cal. 166.09 [Mþ], obsd. 166.79.
1-(Isopropoxymethyl)-4-methoxybenzene (Entry 13, Table 2). IR nmax
1
(neat) ¼ 2967, 2929, 2857, 1613, 1512, 1459, 1248, 1173, 1040, 817, 583 cmꢁ1. H
NMR (CDCl3): d (ppm) ¼ 7.1 (d, J ¼ 8.5 Hz, 2H), 6.7 (d, J ¼ 8.5 Hz, 2H), 4.3 (s,
2H), 3.6 (s, 3H), 3.5 (m, 1H), 1.1 (d, J ¼ 6.0 Hz, 6H). 13C NMR (CDCl3): d
(ppm) ¼ 159.0 (Quat C), 129.7 (Quat C), 129.1, 113.7, 70.6, 69.7, 55.2, 22.1. MS
(ESI) (C10H14O2) ¼ cal. 180.11[Mþ], obsd. 180.69.
1,4-Bis(methoxymethyl)benzene (Entry 1, Table 3). IR nmax (neat) ¼
2976, 2930, 2865, 1450, 1377, 1101, 1018, 849, 812 cmꢁ1 1H NMR (CDCl3): d
.

SYNTHESIS OF BENZYL ALKYL ETHERS
727
(ppm) ¼ 7.3 (s, 4 H), 4.4 (s, 4H), 3.3 (s, 6H). 13C NMR (CDCl3): d (ppm) ¼ 137.6
(Quat C), 129.9, 127.7, 57.9. MS (ESI) (C10H14O2) ¼ cal. 166.10 [Mþ], obsd. 166.58.
1,4-Bis(ethoxymethyl)benzene (Entry 2, Table 3). IR nmax (neat) ¼ 2975,
2927, 2861, 1450, 1209, 1102, 1016, 849, 620 cmꢁ1. 1H NMR (CDCl3): d (ppm) ¼ 7.2
(s, 4 H), 4.3 (s, 4H), 3.4 (d, J ¼ 7.0 Hz, 4H), 1.1 (t, J ¼ 14.0, 7.0 Hz, 6H). 13C NMR
(CDCl3):
d
(ppm) ¼ 137.9 (Quat C), 127.7, 72.4, 65.6, 15.2. MS (ESI)
(C12H18O2) ¼ cal. 217.13 [Mþ þ Naþ], obsd. 217.58.
1,4-Bis(propoxymethyl)benzene (Entry 3, Table 3). IR nmax (neat) ¼ 2963,
1
2932, 2857, 1460, 1360, 1210, 1098, 1045, 959, 811, 759 cmꢁ1. H NMR (CDCl3): d
(ppm) ¼ 7.2 (s, 4 H), 4.4 (s, 4H), 3.3 (t, J ¼ 13.5, 7.0 Hz, 4H), 1.6 (m, 4H), 0.9 (t,
J ¼ 15.0, 7.5 Hz, 6H). 13C NMR (CDCl3): d (ppm) ¼ 138.0 (Quat C), 127.6, 72.6,
72.0, 23.0, 10.7. MS (ESI) (C14H22O2) ¼ cal. 245.04 [Mþ þ Naþ], obsd. 245.58.
1,2-Bis(methoxymethyl)benzene (Entry 4, Table 3). IR nmax (neat) ¼
1
2982, 2926, 2881, 2821, 1455, 1381, 1193, 1095, 968, 943, 755, 617 cmꢁ1. H NMR
(CDCl3): d (ppm) ¼ 7.3 (t, J ¼ 7.5, 3.5 Hz, 2H), 7.2 (d, J ¼ 3.5 Hz, 2H), 4.5 (s, 4H),
3.3 (s, 6H). 13C NMR (CDCl3): d (ppm) ¼ 136.4 (Quat C), 128.7, 127.7, 72.2, 58.1.
MS (ESI) (C10H14O2) ¼ cal. 189.06 [Mþ þ Naþ], obsd. 189.57.
1,2-Bis(ethoxymethyl)benzene (Entry 5, Table 3). IR nmax (neat) ¼ 2973,
2929, 2865, 1458, 11198, 1092, 1016, 846, 618 cmꢁ1 1H NMR (CDCl3): d
.
(ppm) ¼ 7.3 (d, J ¼ 3.5 Hz, 2H), 7.2 (t, J ¼ 5.5, 3.5 Hz, 2H), 4.4 (s, 4H), 3.4 (q,
J ¼ 21.0, 14.0, 7.0 Hz, 4H), 1.1 (t, J ¼ 14, 7.0 Hz, 6H). 13C NMR (CDCl3): d
(ppm) ¼ 136.7 (Quat C), 128.7, 127.7, 70.3, 65.9, 15.3. MS (ESI) (C12H18O2) ¼ cal.
194.16 [Mþ], obsd. 194.91.
1,2-Bis(propoxymethyl)benzene (Entry 6, Table 3). IR nmax (neat) ¼ 2963,
2929, 2860, 1458, 1363, 1092, 1041, 956, 752, 618 cmꢁ1 1H NMR (CDCl3): d
.
(ppm) ¼ 7.3 (d, J ¼ 3.5 Hz, 2H), 7.2 (t, J ¼ 5.5, 3.5 Hz, 2H) 4.5 (s, 4H), 3.4 (t,
J ¼ 13.0, 6.5 Hz, 4H), 1.6(q, J ¼ 21.0, 14.0, 7.0 Hz, 4H), 0.9 (t, J ¼ 15, 7.5 Hz, 6H).
13C NMR (CDCl3): d (ppm) ¼ 136.8 (Quat C), 128.6, 127.6, 72.9, 70.5, 23.0, 10.8.
MS (ESI) (C14H22O2) ¼ cal. 245.16 [Mþ þ Na], obsd. 245.61.
CONCLUSIONS
In summary, we have identified a simple reagent system for the synthesis of
benzyl alkyl ethers under mild, efficient, and environmentally friendly conditions.
FeSO4 is shown to be a good substitute for benzyloxypyridinium triflates and is a
commercially viable reagent. It is also demonstrated that FeSO4 may be recycled
for up to three runs. Therefore, the usefulness of the present method to obtain inter-
esting final products, together with the mild and simple reaction conditions (no dry
solvents or inert atmosphere), make it well suited for the generation of combinatorial
libraries.

728
G. JOSHI AND S. ADIMURTHY
ACKNOWLEDGMENT
The authors gratefully acknowledge the Department of Science and Tech-
nology, New Delhi, India, for the financial support of this project under the Green
Chemistry Task Force Scheme (No. SR=S5=GC-02A=2006).
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