3-acetylcoumarin as a practical ligand for copper-catalyzed C-N coupling reactions at room temperature

Article abstract of DOI:10.1055/s-0029-1218661

The use of coumarin-based ligands was examined in copper-catalyzed C-N cross-coupling reactions. It was found that 3-acetylcoumarin constituted a new, practical ligand for the copper-catalyzed N-arylation of aliphatic amines and imidazole with aryl iodides at room temperature. Aryl bromides could also be aminated efficiently at 80 C. This readily available catalyst system, namely copper(I) iodide and 3-acetylcoumarin, provides a mild and practical method for the synthesis of aromatic amines. Georg Thieme Verlag Stuttgart New York.

Full text of DOI:10.1055/s-0029-1218661

1280
PAPER
3-Acetylcoumarin as a Practical Ligand for Copper-Catalyzed C–N Coupling
Reactions at Room Temperature
3-Acetylcoumari
h
a
Ligand
u
for Copper-
a
Catalyzed
C
–NCouplin
-
gReacti
Z
ons hou Tao,*a,b Wei-Wei Liu,a Ji-You Sun,a Zhi-Ling Cao,a Hui Li,a Ying-Fen Zhanga
a
Department of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005, P. R. of China
Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, Lianyungang 222005, P. R. of China
Fax +86(518)85895403; E-mail: cztao@mail.ustc.edu.cn
b
Received 27 October 2009; revised 6 January 2010
in the N-arylation reaction at room temperature (Table 1).
Several coumarin-based ligands (Figure 1) including cou-
marin-3-carboxylic acid (L1), ethyl coumarin-3-carboxy-
late (L2), coumarin-3-carboxamides L3 and L4, 3-
Abstract: The use of coumarin-based ligands was examined in cop-
per-catalyzed C–N cross-coupling reactions. It was found that 3-
acetylcoumarin constituted a new, practical ligand for the copper-
catalyzed N-arylation of aliphatic amines and imidazole with aryl
iodides at room temperature. Aryl bromides could also be aminated acetylcoumarin (L5), and 3-(1-hydroxyethyl)coumarin
efficiently at 80 °C. This readily available catalyst system, namely
copper(I) iodide and 3-acetylcoumarin, provides a mild and practi-
cal method for the synthesis of aromatic amines.
(L6) were examined (Table 1, entries 1–6). It was found
that moderate yields can be obtained in the presence of
coumarin-3-carboxylate L2 and coumarin-3-carboxam-
Key words: copper, catalysis, cross-coupling, 3-acetylcoumarin,
ides L3 and L4 (entries 2–4). However, the yield was zero
room temperature
when coumarin-3-carboxylic acid (L1) and 3-(1-hydroxy-
ethyl)coumarin (L6) were used (entries 1, 6). We were
pleased to find that 3-acetylcoumarin (L5) dramatically
increase the coupling yield to 90% (entry 5). It is notewor-
thy that crystalline 3-acetylcoumarin is readily available
from commercial sources or can be simply synthesized
from salicylal.
Transition-metal-catalyzed formation of carbon–nitrogen
bonds via cross-coupling reactions represents a powerful
means for the preparation of numerous important products
in pharmaceutical and material sciences.1 Although palla-
dium-catalyzed C–N coupling reactions have been exten-
sively studied,2 copper-based catalyst systems have also
attracted much attention3 because of the low price of cop-
per. Several reviews have detailed the recent progress of
copper-catalyzed C–N coupling reactions.3,4
O
O
O
OH
OEt
NHC6H13
O
O
O
O
O
O
O
To date a number of efficient ligands have been developed
for the copper-catalyzed coupling of aliphatic amines with
aryl halides, including N,N-diethylsalicylamide,5 amino
acids,6 amino alcohols,7 oxime-phosphine oxide,8 and
phosphoramidite.9 However, copper-catalyzed N-aryla-
tion of aliphatic amines at room temperature remained
limited. Recently, Buchwald et al. (diketone ligand),10
Zhao et al. (BINOL ligand)11 and Ding et al (2-pyridyl b-
ketone ligand)12 have successfully performed the copper-
catalyzed arylation of alkylamines at room temperature; it
remains important to find new and more efficient ligands
for room temperature catalysis. In this paper, we report a
new and readily available catalyst system using 3-acetyl-
coumarin (3-acetyl-2H-1-benzopyran-2-one, L5) as the
ligand to construct C(aryl)–N bonds at room temperature.
While the coumarin scaffold has been successful in fluo-
rescence probe chemistry,13 its utility in the copper-cata-
lyzed Ullmann reaction has not yet been demonstrated.
L1
L2
L3
O
O
OH
O
N
O
O
O
O
L4
L5
L6
Figure 1 Coumarin-based ligands
Subsequently, using 3-acetylcoumarin (L5) as the ligand,
a range of combinations of copper sources, bases, and sol-
vents were examined (entries 7–14) and the following
standard coupling reaction conditions were identified: 10
mol% copper(I) iodide as the catalyst and 20 mol% 3-ace-
tylcoumarin as the ligand, relative to the aryl iodide, N,N-
dimethylformamide as the solvent, and cesium carbonate
as the base at room temperature.
The substrate scope of this reaction was then examined
using a variety of aryl iodides and amines under the opti-
mized condition (Table 2). We were delighted to find that
the N-arylation of hexylamine with a variety of aryl io-
dides proceeded smoothly to give the corresponding prod-
ucts 3a–f in good to excellent yields (68–92%) (entries 1–
6). However, aryl iodides with an ortho-substituent do not
readily participate in the reaction. For instance, 2-iodo-
aniline gave 3g in 13% isolated yield (entry 7). Other
Iodobenzene (1a) and hexylamine (2a) were selected as
the model system to optimize the catalytic conditions us-
ing different copper catalysts, ligands, bases, and solvents
SYNTHESIS 2010, No. 8, pp 1280–1284
x
x
.
x
x
.2
0
1
0
Advanced online publication: 05.02.2010
DOI: 10.1055/s-0029-1218661; Art ID: F20709SS
© Georg Thieme Verlag Stuttgart · New York

PAPER
3-Acetylcoumarin as a Ligand for Copper-Catalyzed C–N Coupling Reactions
1281
alkylamines, such as butylamine, phenethylamine, and Table 2 Copper(I) Iodide/3-Acetylcoumarin (L5) Catalyzed
N-Arylation of Alkylamines and Imidazole 2 with Aryl Iodides and
Bromides 1a
benzylamine, were examined and good yields of product
3h–k were obtained (entries 8–11). Sterically more hin-
dered amines, such as cyclohexylamine and piperidine,
however, resulted in significant reduction in the yield (en-
tries 12 and 13).
R1
R2
R3
R2
R3
R1
CuI/L5
X
+
HN
N
1
2
3
O
O
Table 1 Copper-Catalyzed Cross-Coupling of Iodobenzene (1a)
with Hexylamine (2a)a
L5:
I
NHC6H13
CuI/ligand
O
NH2C6H13
+
Entry Aryl halide
R1
R2R3NH
Product Yieldb (%)
1a
2a
3a
X
I
I
I
I
I
I
I
I
I
I
I
I
I
Entry Catalyst
Ligand Base
Solvent
Yieldb (%)
1
2
H
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
BuNH2
3a
3b
3c
3d
3e
3f
90
1
2
CuI
L1
L2
L3
L4
L5
L6
L5
L5
L5
L5
L5
L5
L5
L5
Cs2CO3
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
dioxane
toluene
DMF
DMF
0
55
40
37
90
0
4-Me
4-OMe
4-Br
4-Cl
3-CO2Me
2-NH2
H
85
CuI
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
K2CO3
K3PO4
3
68
3
CuI
4
92
4
CuI
5
91
5
CuI
6
80
6
CuI
7
3g
3h
3i
13
7
CuBr
CuCl
Cu2O
CuSO4
CuI
55
74
12
10
16
17
42
50
8
88
8
9
H
Ph(CH2)2NH2
Ph(CH2)2NH2
BnNH2
85
9
10
11
12
13
14
15
16
17
18
19
20
21
4-Cl
H
3j
89
10
11
12
13
14
3k
3l
81
H
CyNH2
39 (64c)
15
CuI
H
piperidine
3m
3a
3e
3n
3c
3o
3p
3q
3r
CuI
H
Br
Br
Br
Br
I
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
Me(CH2)5NH2
imidazole
65d
70d
68d
55d
93
CuI
4-Cl
4-Ac
4-OMe
H
a Reaction conditions: PhI (1a, 1.0 mmol), hexylamine (2a, 1.5
mmol), CuI (10 mol%), ligand (20 mol%), base (2.0 mmol), solvent
(0.5mL), r.t., 24 h.
b Isolated yields.
In addition to aryl iodides, aryl bromides could also un-
dergo amination mediated by the same ligand when the
temperature was raised to 80 °C (entries 14–17). It was
found that both electron-rich and electron-deficient aryl
bromides can be smoothly converted into the desired
products with moderate isolated yields (55–70%). Fur-
thermore, we found that this catalyst system could be ap-
plied to C–N cross-coupling reactions of imidazole
4-Me
4-OMe
4-Ac
I
imidazole
90
I
imidazole
81
I
imidazole
95
a Reaction conditions: aryl halide (1.0 mmol), amine (1.5 mmol), CuI
(10 mol%), 3-acetylcoumarin (L5, 20 mol%), Cs2CO3 (2.0 mmol),
DMF (0.5mL), r.t. (~25 °C), 24 h.
b Isolated yields.
(entries 18–21). Electron-rich and electron-deficient aryl c At 50 °C.
d At 80 °C
iodides were reacted with imidazole at room temperature
and products 3o–r were obtained in excellent isolated
yields (81–95%).
of aliphatic amines and imidazole at room temperature. 3-
Acetylcoumarin is commercially available or can be easi-
ly synthesized from salicylal, hence, we believe that the
new ligand system may find useful applications in the
synthesis of aromatic amines. Further study on the mech-
anism of the reactions and the applications of this catalytic
To conclude, in the present study we have developed a
new and practical catalyst system, i.e. copper(I) iodide/3-
acetylcoumarin. This system could catalyze N-arylation
Synthesis 2010, No. 8, 1280–1284 © Thieme Stuttgart · New York

1282
C.-Z. Tao et al.
PAPER
HRMS (EI): m/z [M]+ calcd for C13H21NO: 207.1623; found:
177.1614.
system to other cross-coupling reactions are ongoing in
our laboratory.
4-Bromo-N-hexylaniline (3d)14
All reactions were carried out in an oven-dried Schlenk tube under
N2 atmosphere. DMF, dioxane, and toluene were distilled from
CaH2, respectively. 3-Acetylcoumarin (L5) was purchased from
Acros, and L1–L4, L6 were prepared following known procedures.
All aryl halides and amines were purchased from Alfa Aesar or
Acros and used directly. Flash column chromatography was per-
formed on silica 230–400 mesh. IR spectra were recorded on a
IR (KBr): 3426, 2936, 2864, 1599, 1501, 1321, 1259, 1130, 808
cm–1.
1H NMR (400 MHz, CDCl3): d = 7.26–7.18 (m, 2 H), 6.51–6.39 (m,
2 H), 3.60 (br s, 1 H), 3.05 (t, J = 7.1 Hz, 2 H), 1.64–1.51 (m, 2 H),
1.43–1.23 (m, 6 H), 0.90 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 147.6, 132.0, 114.3, 108.6, 44.1,
31.7, 29.5, 26.9, 22.7, 14.1.
1
Nicolet FT IR-500 spectrophotometer. H and 13C NMR spectra
GC-MS (EI): m/z = 255.00, 257.00 [M]+.
were recorded on a Bruker Advance 400 spectrometer at r.t. in
CDCl3; chemical shifts are relative to TMS. GC-MS analysis was
performed on Thermo Scientific AS 3000 Series GC-MS System.
HRMS analysis was performed on Finnigan LCQ Advantage Max
Series MS System.
4-Chloro-N-hexylaniline (3e)
IR (KBr): 3436, 2936, 2864, 1604, 1502, 1322, 1135, 1071, 811
cm–1.
1H NMR (400 MHz, CDCl3): d = 7.10 (d, J = 8.8 Hz, 2 H), 6.50 (d,
J = 8.8 Hz, 2 H), 3.59 (br s, 1 H), 3.05 (t, J = 7.1 Hz, 2 H), 1.65–1.50
(m, 2 H), 1.44–1.20 (m, 6 H), 0.90 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 147.2, 129.1, 121.6, 113.8, 44.2,
31.7, 29.5, 26.9, 22.7, 14.1.
GC-MS (EI): m/z = 211.11 [M]+.
HRMS (EI): m/z [M]+ calcd for C12H18NCl: 211.1128; found:
Coupling of Aryl Iodides with Amines at Room Temperature;
General Procedure
An oven-dried Schlenk tube was charged with CuI (20 mg, 10
mol%), Cs2CO3 (652 mg, 2 mmol), and 3-acetylcoumarin (L5, 38
mg, 20 mol%). The tube was evacuated and backfilled with N2 (this
procedure was repeated 3 ×). Then aryl halide (1.0 mmol), amine
(1.5 mmol), and DMF (0.5 mL) were added under N2. The tube was
sealed and the mixture was stirred at r.t. for 24 h. The resulting sus-
pension was filtered through a pad of silica gel with the help of
CH2Cl2 (50 mL). The filtrate was concentrated and the residue was
purified by column chromatography (silica gel, EtOAc–PE) to af-
ford the product.
211.1135.
Methyl 3-(Hexylamino)benzoate (3f)
IR (KBr): 3416, 2936, 2864, 1712, 1611, 1585, 1525, 1492, 1476,
1441, 1342, 1274, 1244, 1224, 1136, 1107, 744 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.38 (d, J = 7.7 Hz, 1 H), 7.30 (s,
1 H), 7.23 (t, J = 7.9 Hz, 1 H), 6.82 (dd, J = 8.0, 1.8 Hz, 1 H), 3.89
(s, 3 H), 3.14 (t, J = 7.2 Hz, 2 H), 1.69–1.58 (m, 2 H), 1.45–1.22 (m,
6 H), 0.90 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 167.6, 148.0, 131.2, 129.3, 118.9,
117.8, 113.9, 52.1, 44.5, 31.7, 29.4, 26.9, 22.7, 14.1.
GC-MS (EI): m/z = 235.10 [M]+.
HRMS (EI): m/z [M]+ calcd for C14H21NO2: 235.1572; found:
N-Hexylaniline (3a)
IR (KBr): 3422, 3062, 2936, 2864, 1606, 1510, 1461, 1320, 1259,
1131, 1069, 744, 688 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.16 (t, J = 7.8 Hz, 2 H), 6.67 (t,
J = 7.3 Hz, 1 H), 6.59 (d, J = 8.0 Hz, 2 H), 3.50 (br s, 1 H), 3.09 (t,
J = 7.1 Hz, 2 H), 1.66–1.52 (m, 2 H), 1.44–1.24 (m, 6 H), 0.90 (t,
J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 148.7, 129.3, 117.2, 112.8, 44.1,
31.8, 29.7, 27.0, 22.8, 14.2.
GC-MS (EI): m/z = 177.13 [M]+.
HRMS (EI): m/z [M]+ calcd for C12H19N: 177.1517; found:
235.1567.
N-Butylaniline (3h)15
IR (KBr): 3406, 2928, 2867, 1602, 1505, 1476, 1429, 1374, 1319,
177.1510.
1262, 1177, 1149, 747, 691 cm–1.
N-Hexyl-4-methylaniline (3b)14
1H NMR (400 MHz, CDCl3): d = 7.19–7.15 (m, 2 H), 6.68 (t, J = 7.3
Hz, 1 H), 6.62–6.60 (m, 2 H), 3.75 (br s, 1 H), 3.11 (t, J = 7.1 Hz, 2
H), 1.64–1.57 (m, 2 H), 1.47–1.40 (m, 2 H), 0.95 (t, J = 7.3 Hz, 3
H).
13C NMR (100 MHz, CDCl3): d = 148.5, 129.2, 117.0, 112.7, 43.6,
31.7, 20.3, 13.9.
IR (KBr): 3418, 2936, 2864, 1620, 1524, 1477, 1319, 1253, 1134,
1069, 803 cm–1.
1H NMR (400 MHz, CDCl3): d = 6.98 (d, J = 8.1 Hz, 2 H), 6.53 (d,
J = 8.3 Hz, 2 H), 3.34 (br s, 1 H), 3.07 (t, J = 7.1 Hz, 2 H), 2.23 (s,
3 H), 1.77–1.48 (m, 2 H), 1.48–1.13 (m, 6 H), 0.89 (t, J = 6.8 Hz, 3
H).
13C NMR (100 MHz, CDCl3): d = 146.5, 129.8, 126.4, 113.1, 44.6,
31.8, 29.7, 27.0, 22.8, 20.5, 14.2.
GC-MS (EI): m/z = 149.12 [M]+.
N-Phenethylaniline (3i)
GC-MS (EI): m/z = 191.07 [M]+.
IR (KBr): 3422, 3032, 2936, 1604, 1509, 1321, 1261, 1122, 1069,
745, 689 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.31 (t, J = 7.3 Hz, 2 H), 7.20 (m,
5 H), 6.70 (t, J = 7.3 Hz, 1 H), 6.61 (d, J = 7.7 Hz, 2 H), 3.65 (br s,
1 H), 3.40 (t, J = 7.0 Hz, 2 H), 2.91 (t, J = 7.0 Hz, 2 H).
N-Hexyl-4-methoxyaniline (3c)
IR (KBr): 3402, 2936, 2864, 1621, 1461, 1235, 1135, 1068, 815
cm–1.
1H NMR (400 MHz, CDCl3): d = 6.78 (d, J = 8.7 Hz, 2 H), 6.56 (d,
J = 8.1 Hz, 2 H), 3.74 (s, 3 H), 3.08 (br s, 3 H), 1.73–1.47 (m, 2 H),
1.46–1.17 (m, 6 H), 0.90 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 152.2, 142.8, 115.0, 114.3, 56.0,
45.1, 31.8, 29.9, 27.0, 22.8, 14.2.
13C NMR (100 MHz, CDCl3): d = 148.1, 139.4, 129.4, 128.9, 128.7,
126.5, 117.6, 113.1, 45.1, 35.6.
GC-MS (EI): m/z = 197.03 [M]+.
HRMS (EI): m/z [M]+ calcd for C14H15N: 197.1204; found:
197.1197.
GC-MS (EI): m/z = 207.15 [M]+.
Synthesis 2010, No. 8, 1280–1284 © Thieme Stuttgart · New York

PAPER
3-Acetylcoumarin as a Ligand for Copper-Catalyzed C–N Coupling Reactions
1283
4-Chloro-N-phenethylaniline (3j)16
GC-MS (EI): m/z = 174.04 [M]+.
IR (KBr): 3436, 2936, 2864, 1604, 1502, 1322, 1135, 1071, 811
HRMS (EI): m/z [M]+ calcd for C10H10N2O: 174.0793; found:
174.0784.
cm–1.
1H NMR (400 MHz, CDCl3): d = 7.31 (t, J = 7.3 Hz, 2 H), 7.24 (d,
J = 7.3 Hz, 1 H), 7.20 (d, J = 7.1 Hz, 2 H), 7.14–7.06 (m, 2 H), 6.51
(d, J = 8.8 Hz, 2 H), 3.66 (br s, 1 H), 3.36 (t, J = 6.9 Hz, 2 H), 2.89
(t, J = 7.0 Hz, 2 H).
1-[4-(1H-Imidazol-1-yl)phenyl]ethanone (3r)
IR (KBr): 3116, 1679, 1608, 1520, 1492, 1426, 1363, 1307, 1252,
1189, 1111, 1060, 956, 820 cm–1.
13C NMR (100 MHz, CDCl3): d = 146.7, 139.1, 129.2, 128.9, 128.8,
1H NMR (400 MHz, CDCl3): d = 8.09 (d, J = 8.7 Hz, 2 H), 7.96 (s,
1 H), 7.50 (d, J = 8.7 Hz, 2 H), 7.36 (s, 1 H), 7.25 (s, 1 H), 2.64 (s,
3 H).
13C NMR (100 MHz, CDCl3): d = 196.6, 140.9, 136.0, 135.5, 131.3,
130.5, 120.9, 117.9, 26.7.
126.6, 122.1, 114.1, 45.2, 35.5.
GC-MS (EI): m/z = 231.04 [M]+.
N-Benzylaniline (3k)
IR (KBr): 3430, 3032, 1605, 1510, 1493, 1450, 1329, 1276, 734,
GC-MS (EI): m/z = 186.04 [M]+.
HRMS (EI): m/z [M]+ calcd for C11H10N2O: 186.0793; found:
685 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.40–7.30 (m, 4 H), 7.27 (dd,
J = 8.1, 5.6 Hz, 1 H), 7.21–7.12 (m, 2 H), 6.71 (t, J = 7.3 Hz, 1 H),
6.63 (d, J = 7.7 Hz, 2 H), 4.32 (s, 2 H), 4.02 (br s, 1 H).
186.0788.
13C NMR (100 MHz, CDCl3): d = 148.3, 139.6, 129.4, 128.8, 127.6,
127.4, 117.7, 113.0, 48.5.
Acknowledgment
We are grateful to Open-end Funds of Jiangsu Key Laboratory of
Marine Biotechnology (No. 2009HS02), the Six Kinds of Professio-
nal Elite Foundation of Jiangsu Province (No. 07-A-024), the Natu-
ral Science Foundation of Jiangsu Education Department (No.
08KJB150002), and the Natural Science Foundation of Huaihai In-
stitute of Technology (No. Z2008024) for financial support.
GC-MS (EI): m/z = 183.08 [M]+.
HRMS (EI): m/z [M]+ calcd for C13H13N: 183.1048; found:
183.1041.
1-[4-(Hexylamino)phenyl]ethanone (3n)17
IR (KBr): 3436, 2936, 2851, 1665, 1594, 1510, 1391, 1358, 1262,
810 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.82 (d, J = 8.8 Hz, 2 H), 6.54 (d,
J = 8.6 Hz, 2 H), 4.16 (br s, 1 H), 3.18 (br s, 2 H), 2.49 (s, 3 H),
1.70–1.53 (m, 2 H), 1.45–1.23 (m, 6 H), 0.90 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): d = 196.4, 152.4, 130.9, 126.7, 111.4,
43.5, 31.7, 29.4, 26.9, 26.1, 22.7, 14.1.
GC-MS (EI): m/z = 219.06 [M]+.
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Chem. Soc. 2008, 130, 6586. (l) Bertrand, M. B.; Neukom,
J. D.; Wolfe, J. P. J. Org. Chem. 2008, 73, 8851.
1-Phenyl-1H-imidazole (3o)18
IR (KBr): 3112, 1602, 1510, 1305, 1260, 1057, 960, 903, 814, 757,
688, 655, 515 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.86 (s, 1 H), 7.52–7.44 (m, 2 H),
7.42–7.33 (m, 3 H), 7.28 (s, 1 H), 7.21 (s, 1 H).
13C NMR (100 MHz, CDCl3): d = 137.4, 135.6, 130.4, 129.9, 127.6,
121.6, 118.3.
GC-MS (EI): m/z = 144.04 [M]+.
1-(4-Tolyl)-1H-imidazole (3p)18
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Sevignon, M.; Gozzi, C.; Schulz, E.; Lemaire, M. Chem.
Rev. 2002, 102, 1359. (c) Ley, S. V.; Thomas, A. W. Angew.
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IR (KBr): 3126, 1523, 1460, 1301, 1243, 1110, 1053, 959, 899, 814,
731, 656, 525 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.82 (s, 1 H), 7.31–7.22 (m, 5 H),
7.19 (s, 1 H), 2.39 (s, 3 H).
13C NMR (100 MHz, CDCl3): d = 137.5, 135.7, 135.0, 130.4, 130.1,
121.5, 118.4, 20.9.
GC-MS (EI): m/z = 158.05 [M]+.
1-(4-Methoxyphenyl)-1H-imidazole (3q)
IR (KBr): 3118, 1613, 1520, 1461, 1303, 1269, 1243, 1061, 1029,
824 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.77 (s, 1 H), 7.30 (d, J = 8.9 Hz,
2 H), 7.19 (d, J = 9.5 Hz, 2 H), 7.03–6.92 (m, 2 H), 3.85 (s, 3 H).
13C NMR (100 MHz, CDCl3): d = 159.0, 135.9, 130.7, 130.0, 123.3,
118.9, 114.9, 55.6.
Synthesis 2010, No. 8, 1280–1284 © Thieme Stuttgart · New York

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Synthesis 2010, No. 8, 1280–1284 © Thieme Stuttgart · New York