B2O3/Al2O3 as an efficient and recyclable catalyst for the synthesis of β-amino alcohols under solvent-free conditions

Article abstract of DOI:10.1080/00397910801997405

A convenient and efficient procedure for the solvent-free synthesis of β-amino alcohols has been achieved via B2O3/Al2O3-promoted highly regioselective ring opening of epoxides with aromatic amines in good to excellent yields at room temperature. Addition

Full text of DOI:10.1080/00397910801997405

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B O /Al O as an Efficient and
2
3
2 3
Recyclable Catalyst for the
Synthesis of β-Amino Alcohols
under Solvent-Free Conditions
a b
b
b
Changfu Zhang
, Jiuxi Chen , Xiaochun Yu ,
b
b
a
Xian Chen , Huayue Wu & Jianping Yu
a
College of Life Science, Guizhou University ,
Guiyang, China
b
College of Chemistry and Materials Engineering,
Wenzhou University , Wenzhou, China
Published online: 12 Jun 2008.
To cite this article: Changfu Zhang , Jiuxi Chen , Xiaochun Yu , Xian Chen ,
Huayue Wu & Jianping Yu (2008) B O /Al O as an Efficient and Recyclable Catalyst
2
3
2 3
for the Synthesis of β-Amino Alcohols under Solvent-Free Conditions, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic
Organic Chemistry, 38:12, 1875-1887, DOI: 10.1080/00397910801997405
To link to this article: http://dx.doi.org/10.1080/00397910801997405
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1
Synthetic Communications , 38: 1875–1887, 2008
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910801997405
B O /Al O as an Efficient and Recyclable
2
3
2
3
Catalyst for the Synthesis of b-Amino Alcohols
under Solvent-Free Conditions
1
,2
2
2
Changfu Zhang, Jiuxi Chen, Xiaochun Yu, Xian Chen,
2
2
1
Huayue Wu, and Jianping Yu
College of Life Science, Guizhou University, Guiyang, China
1
2
College of Chemistry and Materials Engineering, Wenzhou University,
Wenzhou, China
Abstract: A convenient and efficient procedure for the solvent-free synthesis of
b-amino alcohols has been achieved via B =Al -promoted highly regioselec-
2
O
3
2 3
O
tive ring opening of epoxides with aromatic amines in good to excellent yields at
room temperature. Additionally, the catalyst can be recycled without affecting the
catalytic property.
2 3 2 3
Keywords: b-Amino alcohols; Anilines; B O =Al O , Epoxides, Solvent-free
conditions
INTRODUCTION
b-Amino alcohols are important intermediates in the synthesis of a large
number of biologically active natural and synthetic products, amino
[
1]
[
2]
[3]
acids, and chiral auxiliaries. One of the most common and practical
methods for the preparation of these compounds is the aminolysis of epox-
[
4]
ides at elevated temperature with an excess of amines. Subsequently,
various activators=promoters have been developed to perform the epoxide
ring-opening reaction under mild conditions such as metal amides
[
5]
(
lithium, magnesium, lead, tin), metal alkoxide [diisopropoxyaluminium
Received September 9, 2007
Address correspondance to Hauyue Wu, College of Chemistry and Materials
Engineering, Wenzhou University, Wenzhou, China, 325027. E-mail:
huayuewu@wzu.edu.cn
1
875

1876
C. Zhang et al.
[
6]
trifluoroacetate (DIPAT), Ti(OiPr) ], metal triflates (lithium, Ph SbOTf,
4
4
[7]
lanthanide, tin, scandium), metal halides (TaCl , ZrCl , VCl , ZnCl ,
[9]
CeCl , BiCl ), silica under high pressure, ionic liquids,
5
4
3
2
[11]
[
8]
[10]
water,
3
3
[
12]
[13]
clay,
and others.
However, there are some limitations with these
methodologies such as longer reaction times, use of stoichiometric or
moisture-sensitive catalysts, and hazardous organic solvents. More
recently, Robinson and coworkers have reported the aminolysis of
[
14]
epoxides using a mesoporous aluminosilicate catalyst. These reactions
also require longer reaction times (6–12 h). Therefore, the development
of convenient, efficient, and environmentally friendly catalytic systems
for their preparation is highly attractive.
Recently, some organic reactions running on the surfaces of solids
[15]
such as mesoporous aluminosilicate, titanosilicate molecular sieves,
[14]
[
16]
[17]
alumina, and silica gel have been reported, and these heterogeneous
catalysts offer several intrinsic advantages such as the easy separation of
product, the convenient recovery and reuse of catalyst, and the minimiza-
tion of waste production. Herein we report that B O =Al O efficiently
2
3
2
3
promoted the ring-opening reactions with aromatic amines at room tem-
perature under solvent-free conditions.
RESULTS AND DISCUSSION
First, to optimize the best reaction conditions, styrene oxide 1a (1 mmol)
was taken as a representative substituted epoxideand treated with aniline
2
revealed that the B O =Al O -promoted ring-opening reaction best pro-
a (1 mmol) under various conditions (Table 1). The results clearly
2
3
2
3
ceeded for 2 h at room temperature under solvent-free conditions to give
3
a in excellent yield (yield 90%) with high regioselectivity (Table 1, entry
). Prolonging the reaction time did not improve the yield of 3a (Table 1,
5
entries 5, 6). The yield was unsatisfactory when an organic solvent was
used such as CH CH OH, CH CN, CH Cl , or H O (Table 1, entries
3
2
3
2
2
2
1
of B O =Al O ; better conversions were achieved by using 0.03 g
–4). We found that the yield was affected by adding different amounts
2
3
2
3
B O =Al O (Table 1, entries 5, 7, 8). When only Al O was used as
2
3
2
3
2
3
the catalyst or no catalyst was used for the ring-opening reactions, 3a
was obtained in low yield (Table 1, entries 9 and 10).
Because of the good results obtained, we applied the optimal proto-
col to a variety of amines (Table 2). Most of the reactions proceeded
smoothly at room temperature in good to excellent yields affording 3
as major products by amine attack at the benzylic carbon. Further studies
indicated that strong electron-drawing groups (ꢀNO ) on the aromatic
2
ring affected the product yields. The high regioselectivity obtained is

B O
2 3
/Al
O
2 3
as an Efficient and Recyclable Catalyst
1877
Table 1. Ring-opening of styrene oxide with aniline under various conditions
a
b
Entry
Solvent
Time (h)
Yield (%)
Ratio 3a:4a
1
2
3
4
5
6
CH CH OH
2
2
2
2
2
5
2
2
2
5
35
30
32
40
90
91
85
90
25
30
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
3
3
2
2
CH
CH
CN
Cl
2
H O
2
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
c
7
d
8
9
e
f
1
0
a
b
c
Isolated yield.
Regioisomers were determined using H NMR.
1
0
2
.01 g of B O
3
2 3
=Al O was used as a catalyst.
d
0.05 g of B O =Al O was used as a catalyst.
In the absence of catalyst.
2
3
2
3
e
f
0
2 3
.03 g of Al O was used as a catalyst.
noticeable (Table 2, entry 5). The steric effect also affected the reaction
significantly in the yield of product (Table 2, entry 7). Furthermore,
the hindered amines quite influenced the ring-opening reaction, and elev-
ated temperature was needed (Table 2, entries 8, 9).
Various epoxides were treated with aniline in the presence of
B O =Al O (Table 3). Interestingly, aliphatic and aromatic epoxides
2
3
2
3
gave the major products with the opposite regiochemistry (Table 3, entry
). We suggest that the attack position of the nucleophile is governed by
1
the nature of epoxides and the stability of carbonium ion. In the case of
aryl epoxides, the positive charge on oxygen appears to be localized on
the more highly substituted benzylic carbon leading to the major product
5. For aliphatic epoxides, possibly steric factors predominate over elec-
tronic factors and the absolutely selective nucleophilic attack at the less
hindered carbon of epoxide to afford the product 6 (Table 3, entries 2–
6
3
). Furthermore, we investigated cyclohexene oxide with aniline (Table
, entry 7); the resultant racemic b-amino cyclohexanol was identified
1
as the trans-diastereoisomer on the basis of H NMR spectral data.

1878
C. Zhang et al.
Table 2. Ring opening of styrene oxide with various amines under solvent-free
conditions at room temperature catalyzed by B =Al
2
O
3
2 3
O
.
Entry
a
b
R
1
R
2
Products Time (h) Yield (%)
Ratio 3:4
1
2
3
4
5
6
7
Ph
4-Me(C
4-Cl(C H )
H
H
H
H
H
H
H
3a
3b
3c
3d
3e
3f
2
2
2
2
3
2
3
90
85
89
93
62
94
75
>99:1
98:2
94:6
6
4
H )
6
4
3-Cl(C
2-NO
2-OMe(C H )
6
4
H )
95:5
(C
2 6
H
4
)
>99:1
93:7
95:5
6
4
3g
c
8
Ph
Ph
CH
Ph
3
3h
3i
4
3.5
98
55
94:6
90:10
c
9
a
Isolated yields.
b
c
1
Regioisomers were determined using H NMR.
At 60 C.
ꢁ
Finally, the reusability of B O =Al O was further investigated in
2
3
2
3
subsequent aminolysis reactions, taking the aminolysis of styrene oxide
as an example (Scheme 1). The catalyst was easily recovered by simple fil-
tration after diluting the reaction mixture with ethyl acetate and was
reused after drying under vacuum. The catalyst (B O =Al O ) was reused
2
3
2
3
for four runs without any appreciable loss of activity.
In summary, B O =Al O is a highly efficient, mild, and reusable
2
3
2
3
catalyst for ring-opening reaction of epoxides with amines with excellent
regio- and stereoselectivity. The low cost and apparently nontoxic nature
of B O =Al O and the solvent-free reaction conditions make it environ-
2
3
2
3
mentally friendly and potentially useful for industrial applications.
EXPERIMENTAL
All the melting points were uncorrected. Chemicals and solvents were
either purchased or purified by standard techniques. IR spectra were

B O
2 3
/Al
O
2 3
as an Efficient and Recyclable Catalyst
1879
Table 3. Ring opening of various epoxides with aniline in the presence of
=Al at room temperature under solvent-free conditions
2
B O
3
2 3
O
a
Entry
1
Epoxide
Products
Time (h)
3
Yield (%)
5a
98
2
3
6b
6c
3
75
72
3.5
4
5
6d
6e
3
3
97
78
6
7
6f
4
60
76
6g
3.5
a
Isolated yields.
1 13
recorded on a Bruker Equinox 55 spectrometer. H NMR and C NMR
spectra were recorded on a Bruker AC 300 instrument using CDCl as the
3
solvent with tetramethylsilane (TMS) as an internal standard at room
temperature. Chemical shifts are given in d relative to TMS; the coupling
constants J are given in hertz. Compounds were properly characterized
by elemental analysis carried out using a Carlo-Erba EA1112 instrument.
Silica gel 60 GF254 was used for analytical and preparative thin-layer
chromatography (TLC).

1880
C. Zhang et al.
Scheme 1. Reusing of the catalyst in subsequent aminolysis reactions. Run 1:
0%; run 2: 90%; run 3: 88%; run 4: 87%.
9
General Procedure for the Synthesis of b-Amino Alcohols
B O =Al O (0.03 g, 15% w=w) was added to a magnetically stirred mix-
2
3
2
3
ture of epoxide (1 mmol) and amine (1 mmol), and the reaction mixture
was stirred at room temperature for the appropriate time. After com-
pletion of the reaction, as indicated by TLC, the reaction mixture was
diluted with ethyl acetate. The catalyst was separated by filtration, and
then the solution was washed (ethyl acetate) and dried (Na SO ). After
2
4
evaporation of the solvent under reduced pressure, the crude product
was obtained. The corresponding purified form was obtained by flash-
column chromatography.
Characterization Data of All the Products
[13l]
-Phenyl-2-(phenylamino)ethanol (3a)
2
ꢀ1
1
Oil. IR n (cm ): 3397, 2932, 2873, 1600, 1502, 1451. H NMR (300 MHz,
CDCl ): d ¼ 7.26–7.38 (m, 5H), 7.12 (m, 2H), 6.70 (m, 1H), 6.58 (m, 2H),
3
1
.52 (m, 2H), 3.76–3.97 (m, 2H), 1.84 (s, 1H, OH). C MNR (75 MHz,
3
4
CDCl ): d ¼ 147.17, 140.05, 129.12, 128.80, 127.58, 126.68, 117.83,
3
1
13.79, 67.33, 9.79.
[8b]
2
-(p-Toluidino)-2-phenylethanol (3b)
ꢁ
ꢀ1
Solid, mp: 59–61 C. IR n (cm ): 3446, 3026, 2923, 2853, 1572, 1491,
1
1
445, 1373. H NMR (300 MHz, CDCl ): d ¼ 6.96–7.39 (m, 5H), 6.95
3
(
m, 2H), 6.54 (m, 2H), 4.48 (m, 2H), 3.68–3.94 (m, 2H), 2.53 (d,
C MNR (75 MHz, CDCl3):
1
3
J ¼ 2.82 Hz, 1H), 2.24 (s, 3H).
d ¼ 144.85, 140.24, 129.58, 128.67, 128.39, 127.42, 126.65, 113.97,
6
2
7.20, 60.07, 20.30.
[
8b]
-(4-Chlorophenylamino)-2-phenylethanol (3c)
ꢁ
ꢀ1
Solid, mp: 63–65 C. IR n (cm ): 3400, 3028, 2927, 2853, 1598, 1498,
1
1
454. H NMR (300 MHz, CDCl ): d ¼ 7.24–7.39 (m, 5H), 7.04 (m,
3

B O
2 3
/Al
O
2 3
as an Efficient and Recyclable Catalyst
1881
2
1
H), 6.47 (m, 2H), 4.65 (d, J ¼ 6.12 Hz, 1H), 4.43 (dd, J ¼ 4.07, 6.91 Hz,
1
H), 3.92 (m, 1H), 3.70 (m, 1H), 2.41 (br s, 1H, OH). C MNR (75 MHz,
3
CDCl ): d ¼ 145.68, 139.51, 128.83, 128.73, 127.60, 126.54, 122.20,
3
1
14.78, 67.05, 59.76.
[13o]
-(3-Chlorophenylamino)-2-phenylethanol (3d)
2
ꢁ
ꢀ1
1
Solid, mp: 53–54 C. IR n (cm ): 3404, 3028, 2930, 2877, 1596, 1493. H
NMR (300 MHz, CDCl ): d ¼ 7.33–7.38 (m, 5H), 7.03 (m, 1H), 6.70 (m,
3
1
1
H), 6.58 (t, J ¼ 2.08, 4.16 Hz, 1H), 6.46 (m, 1H), 4.72 (d, J ¼ 5. 12 Hz,
1
3
H), 4.46 (m, 1H), 3.89 (m, 1H), 3.72 (m, 1H), 2.42 (m, 1H). C NMR
(
1
75 MHz, CDCl ): d ¼ 148.32, 139.39, 134.66, 130.06, 128.77, 127.65,
3
26.54, 117.55, 113.43, 111.82, 66.98, 59.45.
[7f]
2
-(2-Nitrophenylamino)-2-phenylethanol (3e)
ꢀ1
1
Oil. IR n (cm ): 3372, 3030, 2930, 2826, 1616, 1507, 1448. H NMR
(
300 MHz, CDCl ): d ¼ 8.20 (m, 1H), 6.62–6.67 (m, 2H), 4.74 (dd,
3
1
3
J ¼ 6.15, 10.53 Hz, 1H), 3.92–4.15 (m, 2H). C MNR (75 MHz, CDCl ):
3
d ¼ 144.57, 138.64, 136.02, 132.48, 129.03, 128.67, 128.03, 126.55, 115.88,
1
15.08, 66.99, 59.18.
[
8b]
2
-(2-Methoxyphenylamino)-2-phenylethanol (3f)
ꢀ1
1
Oil. IR n (cm ): 3396, 3053, 2926, 1598, 1502, 1450. H NMR (300 MHz,
CDCl ): d ¼ 7.26–7.40 (m, 5H), 6.69–6.83 (m, 3H), 6.43 (d, J ¼ 7.48 Hz,
3
1
5
1
H), 5.07 (d, J ¼ 5.47 Hz, 1H), 4.53 (d, J ¼ 4.41 Hz, 1H), 3.74–3.98 (m,
1
3
H). C MNR (75 MHz, CDCl ): d ¼ 147.00, 140.14, 136.87, 128.63,
3
26.60, 120.98, 116.97, 111.36, 109.27, 67.31, 59.65, 55.31.
[13m]
2
-(Naphthalen-1-ylamino)-2-phenylethanol (3g)
ꢁ
ꢀ1
Solid, mp: 130–132 C. IR n (cm ): 3421, 3305, 3055, 2924, 2863, 1580,
1
1
525, 1477. H NMR (300 MHz, CDCl ): d ¼ 7.22–8.11 (m, 11H), 6.41
3
(
dd, J ¼ 1.02, 1.05 Hz, 1H), 5.38 (br s, 1H, NH), 4.66 (dd, J ¼ 4.06,
7
1
.03 Hz, 1H), 4.05 (dd, J ¼ 4.05, 11.14 Hz, 1H), 3.87 (dd, J ¼ 7.09,
3
1
3
2.13 Hz, 1H), d 2.09 (br s, 1H, OH). C MNR (75 MHz, CDCl ):
d ¼ 142.10, 139.75, 134.19, 128.71, 128.40, 128.16, 127.86, 126.60,
1
25.71, 124.83, 123.72, 120.00, 117.77, 106.49, 67.43, 59.78.

1882
C. Zhang et al.
[
13n]
2
-(Methyl(phenyl)amino)-2-phenylethanol (3h)
ꢀ1
1
Oil. IR n (cm ): 3404, 3028, 2884, 2816, 1598, 1500, 1452, 1378. H
NMR (300 MHz, CDCl ): d ¼ 7.26–7.45 (m, 7H), 6.48 (m, 3H), 5.01
3
(
dd, J ¼ 4.62, 8.31 Hz, 1H), 3.48 (m, 2H), 2.95 (s, 3H), 2.56 (s, 1H).
1
3
C MNR (75 MHz, CDCl ): d ¼ 149.92, 141.89, 129.25, 128.53,
3
1
2
27.83, 125.89, 117.49, 113.21, 71.69, 62.03, 39.37.
-(Diphenylamino)-2-phenylethanol (3i)
ꢀ1
1
Oil. IR n (cm ): 3400, 3052, 2932, 2873, 1600, 1507, 1456. H NMR
(
(
2
1
300 MHz, CDCl ): d ¼ 7.21–7.31 (m, 9H), 6.95–7.02 (m, 6H), 5.39
3
dd, J ¼ 6.00, 2.25 Hz, 1H), 4.03–4.10 (m, 2H), 1.71 (dd, J ¼ 5.25,
1
3
.13 Hz, 1H). C MNR (75 MHz, CDCl ): d ¼ 146.71, 139.14, 129.22,
3
29.12, 128.56, 127.56, 127.50, 123.08, 122.27, 64.38, 62.73. Anal. Calcd.
for C H NO : C, 83.01; H, 6.62. Found: C, 82.81; H, 6.47.
2
0
19
[
8g]
2
-(4-Chlorophenyl)-2-(phenylamino)ethanol (5a)
ꢀ1
1
Oil. IR n (cm ): 3400, 3052, 2931, 2874, 1601, 1498. H NMR (300 MHz,
CDCl ): d ¼ 7.31 (m, 4H), 7.12 (dd, J ¼ 7.44, 8.43 Hz, 2H), 6.71 (m,1H),
3
6
1
1
.54 (d, J ¼ 7.68 Hz, 2H), 4.53 (s, 1H), 4.46 (m, 1H), 3.89 (d, J ¼ 2.64 Hz,
1
3
H), 3.71 (m, 1H), 1.91 (s, 1H). C NMR (75 MHz, CDCl ): d ¼ 146.88,
3
38.67, 133.23, 129.16, 128.94, 128.08, 118.07, 113.80, 67.11, 59.26.
[13l]
-(Phenylamino)propan-2-ol (6b)
1
ꢀ1
1
Oil. IR n (cm ): 3396, 2926, 2854, 1602, 1500, 1453. H NMR (300 MHz,
CDCl ): d ¼ 7.17–7.26 (m, 2H), 6.74 (t, J ¼ 7.32 Hz, 1H), 6.66 (m, 3H),
3
3
1
.96–4.06 (m, 1H), 3.22 (dd, J ¼ 3.33, 12.93 Hz, 1H), 2.98 (dd, J ¼ 8.55,
1
3
2.93 Hz, 1H), 2.35 (br s, 1H), 1.25 (d, J ¼ 6.27 Hz, 3H). C NMR
(75 MHz, CDCl ): d ¼ 148.12, 129.30, 117.89, 113.77, 66.29, 50.57, 20.73.
3
[8b]
2
-Azido-2-(4-bromophenyl)ethanol (6c)
ꢀ1
1
Oil. IR n (cm ): 3407, 3026, 2923, 2853, 1572, 1496. H NMR (300 MHz,
CDCl ): d ¼ 7.12–7.27 (m, 2H), 6.78 (m, 1H), 6.69 (m, 2H), 4.06 (dd,
3
J ¼ 5.99, 7.22 Hz, 1H), 3.59–3.70 (m, 2H), 3.38 (dd, J ¼ 4.37, 13.27 Hz,
1
3
1
H), 3.23 (dd, J ¼ 7.27, 13.30 Hz, 1H). C NMR (75 MHz, CDCl ):
3
d ¼ 147.64, 129.40, 117.98, 113.24, 69.35, 57.94, 47.53.

B O
2 3
/Al
O
2 3
as an Efficient and Recyclable Catalyst
1883
[13n]
-(Benzyloxy)-3-(phenylamino)propan-2-ol (6d)
1
ꢀ1
1
Oil. IR n (cm ): 3396, 3027, 2861, 1603, 1504, 1456, 1095. H NMR
(
6
3
300 MHz, CDCl ): d ¼ 7.33–7.43 (m, 5H), 7.21 (m, 2H), 6.76 (m, 1H),
3
.65 (d, J ¼ 8.25 Hz, 2H), 4.60 (s, 2H), 4.08 (d, J ¼ 3.09 Hz, 2H),
.54–3.66 (m, 2H), 3.32 (dd, J ¼ 4.32, 12.78 Hz, 1H), 3.19 (dd,
1
3
J ¼ 7.14, 12.78 Hz, 1H), 2.64 (br s, 1H, OH). C NMR (75 MHz,
CDCl ): d ¼ 148.14, 137.69, 129.23, 128.50, 127.90, 127.80, 117.74,
3
1
13.12, 73.49, 72.33, 69.04, 46.58.
[8b]
-Azido-3-phenoxypropan-2-ol (6e)
1
ꢁ
ꢀ1
1
Solid, mp: 58–60 C. IR n (cm ): 3398, 3050, 2925, 1598, 1498, 1241. H
NMR (300 MHz, CDCl ): d ¼ 6.68–7.36 (m, 10H), 4.25 (dd, J ¼ 10.56,
3
1
7.01 Hz, 1H), 4.06 (m, 2H), 3.44 (dd, J ¼ 4.29, 12.96 Hz, 1H), 3.29
1
3
(
dd, J ¼ 7.17, 12.96 Hz, 1H), 2.79 (s, 1H, OH). C NMR (75 MHz,
3
CDCl ): d ¼ 158.28, 147.97, 129.53, 129.28, 121.24, 117.97, 114.43,
1
13.21, 69.88, 68.68, 46.48.
[13m]
-(Phenylamino)octan-2-ol (6f)
1
ꢁ
ꢀ1
1
Solid, mp: 46–47 C. IR n (cm ): 3268, 2926, 2854, 1604, 1502, 1457. H
NMR (300 MHz, CDCl ): d ¼ 7.16–7.28 (m, 2H), 6.74 (m, 1H), 6.69 (m,
3
2
1
H), 4.02 (s, 1H), 3.85 (s, 1H), 3.29 (dd, J ¼ 3.12, 12.84 Hz, 1H), 3.02 (m,
1
3
H), 1.33–1.56 (m, 10H), 2.00 ( s, 1H), 0.92 (t, J ¼ 6.51, 6.90 Hz, 2H).
C
NMR (75 MHz, CDCl ): d ¼ 148.25, 129.27, 117.84, 113.22, 70.35, 50.26,
3
3
5.07, 31.76, 29.31, 25.58, 22.59, 14.08.
[13l]
Anti-2-(phenylamino)cyclohexanol (6g)
ꢁ
ꢀ1
Solid, mp: 57–59 C. IR n (cm ): 3392, 3025, 2925, 2852, 1601, 1500,
1
1
446. H NMR (300 MHz, CDCl ): d ¼ 7.18–7.24 (m, 2H), 6.72–6.80
3
(
m, 3H), 3.25 (m, 2H), 3.18 (m, 1H), 3.11 (br s, 1H, OH), 2.13 (d,
1
3
J ¼ 12.04 Hz, 2H), 1.71–1.81 (m, 2H), 1.29–1.44 (m, 4H). C NMR
(
75 MHz, CDCl ): d ¼ 147.73, 129.21, 118.13, 114.93, 74.30, 59.90,
3
3
3.06, 31.44, 24.86, 24.16.
ACKNOWLEDGMENT
We are grateful to the National Natural Science Foundation of China
(
Nos. 20476098 and 20504023), and Natural Science Foundation of

1884
C. Zhang et al.
Zhengjiang Province (Nos. Y405015 and Y405113), and Science and
Technology Program of Zhengjiang Province (No. 2003C31026) for
financial support.
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