CrCl3·6H2O/hydrogenated bis-Schiff base as a new efficient catalyst system for synthesis of bis(indoly) methane

Article abstract of DOI:10.1002/cjoc.201180362

CrCl₃·6H₂O/hydrogenated bis-Schiff base is found to be an effective catalyst system for synthesis of bis(indoly) methane via electrophilic addition reaction of indoles with aldehydes using acetonitrile as the solvent. The yields of i

Full text of DOI:10.1002/cjoc.201180362

FULL PAPER
CrCl3•6H2O/Hydrogenated Bis-Schiff Base as a New Efficient
Catalyst System for Synthesis of Bis(indoly) Methane
Yang, Yongleia,b(杨永磊)
Xie, Zhengfeng*,a(解正峰)
Wang, Jide*,b(王吉德)
a College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi, Xinjiang 830046, China
b Key Laboratory of Oil & Fine Chemicals of Education of Ministry, Xinjiang University,
Urumqi, Xinjiang 830046, China
CrCl3•6H2O/hydrogenated bis-Schiff base is found to be an effective catalyst system for synthesis of bis(indoly)
methane via electrophilic addition reaction of indoles with aldehydes using acetonitrile as the solvent. The yields of
isolated products are from good to excellent.
Keywords Schiff bases, indole, bis(indoly) methane, aldehydes
Introduction
amine N-atom. In order to develop a new method for
synthesis of BIM and overcome the problems on previ-
ous work, we use hydrogenated bis-Schiff base complex
as catalyst for such reaction of indoles with aldehydes.
In continuation of our ongoing interest,20 in this pa-
per, we report a simple procedure for the synthesis of
BIM via electrophilic substitution reaction of indoles
with aldehydes using acetonitrile as the solvent.
Indole derivatives are known for their various appli-
cations in material sciences, agrochemicals and phar-
maceuticals.1 Bis(indoly) methanes (BIM) and their
analogues compounds exhibit a wide range of biological
activities such as antibacterial and antitumor properties.2
Because of their wide occurrence as natural products
and various biological activities, synthesis of these
bis(indolyl) methanes has received an increasing atten-
tion in recent years. The simple method for the synthesis
of this class of compounds is via condensation of two
molecules of indoles with one molecule of aldehyde in
the presence of protic3 or Lewis acids.4 In view of that,
several synthetic methods for the preparation of BIMs
have been reported by using catalysts such as
ion-exchange resin,5 lanthanide triflate,6 tri-
Results and discussion
To assess the catalytic reactivity of ligands L1—L6,
they were used to catalyze the addition of indole to
benzaldehyde as the model reaction, and the results are
listed in Table 1. It was observed that the reaction could
be preceded in the presence of L6 (5 mol%) at room
temperature.
Then, several metal salts were investigated. All
metal salt with L4 could effectively catalyze the model
reaction. As shown in Table 2. When the L6 ＋
CrCl3•6H2O (5 mol%) was the catalyst, the yield of
BIM was obtained in high yield of 99% (Table 2, Entry
2). The product was just achieved in 63% yield when
the catalyst was only CrCl3•6H2O, and did not have sig-
nificant yield increase when the catalyst amount in-
creased from 5 mol% to 10 mol% (Table 2, Entries 7,
8).
With the optimal reaction conditions in hand, the ef-
fect of substituent in the aromatic ring of aldehyde was
investigated. The optimal conditions of BIM derivatives
were summarized in Table 3. The obtained results are
encouraging, we found aldehydes with both electron
donating and electron withdrawing groups can afford
BIM in high yields (up to 99%) as shown in Table 3.
chloro-1,3,5-triazine,7 ZrOCl2•8H2O/silica gel,8 hetero-
poly acids,9 ammonium chloride,2 InCl3,
I2,11
10
Sc(OTf)3,12 Zr(DS4),13 Cu(OTf)214 and gold.15 However,
these methods still have some disadvantages, since
many of these methods suffer from one or more disad-
vantage like the use of expensive reagents,6,10,12-15 com-
plicated manipulations9 or hazardous chemicals em-
ployed.
Due to these problems, development of an efficient
and versatile method for the preparation of BIM has still
been needed. Schiff base complex has received a great
deal of attention in catalysis domain.16-19 Compared to
the Schiff bases, the corresponding hydrogenated Schiff
bases are expected to be more stable and readily form
metal complexes. The hydrogen atom on the secondary
amine produced after the reduction of the azomethine
(CH＝N) fragment of the Schiff base is expected to be
significantly acidic due to metal ion coordination to the
*
E-mail: xiezhf72@yahoo.com.cn; awangjd@xju.edu.cn; Fax: 0086-991-8582807
Received April 18, 2011; revised June 2, 2011; accepted June 23, 2011.
Project Supported by the National Natural Science Foundation of China (Nos. 20962018, 20862015, 20762009 and 20562011).
Chin. J. Chem. 2011, 29, 2091— 2096
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2091

Yang, Xie & Wang
FULL PAPER
Table 1 Different ligand mediated reaction of indole with benzaldehyde
Isolate
Entry
1
Ligand (L)
Solvent
CH3CN
Time/h
yield/%
48
48
48
48
trace
2
3
4
CH3CN
CH3CN
CH3CN
trace
trace
trace
5
6
CH3CN
CH3CN
48
48
trace
40
To explain the actual role of hydrogenated bis-Schiff
base/CrCl3•6H2O system in the synthesis of bis(indolyl)
methanes, we explore probable mechanism of the reac-
tion.21 First, hydrogenated bis-Schiff base/CrCl3•6H2O
system activates the carbonyl group of the aromatic al-
dehyde to give intermediate 2, followed by indole at-
tacking 2 to give 3; after loss of H2O from 3 to afford 4,
while as an electrophile, intermediate 4 was attacked by
a second molecule of indole, the target products 5 were
formed to regenerate the catalyst (Figure 1).
In summary, we have demonstrated that hydrogen-
ated bis-Schiff base/CrCl3•6H2O system can act as an
efficient catalyst for the condensation reaction of indole
with aldehydes using acetonitrile as the solvent through
an environmentally acceptable process. The products
were obtained in high yields (up to 99%). Further work
is in progress to explore the bis-Schiff base/metal salt
catalytic system to other organic transformation.
Table 2 L6＋metal salt system catalyzed the reaction of indole
with benzaldehyde
Entry L6＋M (5 mol%)
Time/h Yield/%
1
2
3
4
5
6
7
8
L6＋Cu(CH3COO)2•H2O
15
15
15
15
15
15
30
30
75
99
46
80
76
68
63
62
L6＋CrCl3•6H2O
L6＋KCl
L6＋Cu(NO3)2•6H2O
L6＋NiCl2•2H2O
L6＋Mn(CH3COO)2•H2O
CrCl3•6H2O
CrCl3•6H2O 10 mol%
2092
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Chin. J. Chem. 2011, 29, 2091— 2096

CrCl3•6H2O/Hydrogenated Bis-Schiff Base as a New Efficient Catalyst System
Table 3 Scope of substrates
Experimental
Chemicals and apparatus
Melting points were determined in open capillaries
and are uncorrected. The completion of reactions was
monitored by TLC. Purification of reaction products
was carried out by column chromatography using
Qingdao silica gel (300—400 mesh). Analytical thin-
layer chromatography (TLC) was performed on silica
gel GF254 (Qingdao, China) with ethyl acetate and pe-
troleum ether (60—90 ℃) and detected by UV light or
iodine vapor. The IR spectrum was recorded on a
and 13C NMR spectra were recorded on a VARIAN
INOVA 400 MHz FT-NMR spectrometer. Elemental
analyses were performed on a Thermo Flash EA1112
elemental analyzer.
Entry R
Product Yield/%
m.p./℃
1
H
3a
3b
3c
3d
3e
3f
98
93
90
80
91
92
88
95
84
85
88
95
99
99
118—12010
235—23710
210—2121b
220—2221c
92—94
2
4-NO2
2-NO2
3-NO2
4-F
1
3
Bruker Equinox 55 FT-IR spectrophotometer. The H
4
5
6
4-Cl
4-Br
97—991b
7
3g
106—10710
147—14810
103—1042
132—13310
101—10310
106—1081d
185—18610
133—1357
General procedure for preparation of imines and
amine
8
2.4-Dichloride 3h
9
2-OH
4-OH
4-CH3
3i
2-Phenyl-2H-1,2,3-triazole-4-carbaldehyde
(10
mmol),22 amine (10 mmol) and chloroform (5 mL) were
mixed thoroughly with stirring under reflux. After stir-
ring for 2 h, the mixture was cooled to room tempera-
ture and filtered to give corresponding imine and several
(L3 and L5) can be reduced to amines (L4 and L6) in the
presence of sodium borohydride as the reducing reagent.
The solution was extracted with ethyl ether, dried over
magnesium sulfate, and the solvent was removed under
reduced pressure to give a crude product. Eventually,
both the pure imines and amine L1—L6 can be crystal-
lized from ethanol.
10
11
12
13
14
3j
3k
3-OCH3, 4-OH 3l
4-OCH3
2-OCH3
3m
3n
15
16
3o
78
95
111—11310
3p
3q
78—80
Spectroscopic data for products
5-Ethyl-4-[(2-phenyl-2H-1,2,3-triazol-4-yl)meth-
yleneamino]-4H-1,2,4-triazole-3-thiol (L1) Yellow
1
solid; m.p. 215—217 ℃; H NMR (DMSO, 400 MHz)
17
94
122—124
δ: 1.30 (t, J＝7.6 Hz, 3H), 2.84 (q, J＝7.6 Hz, 4H), 7.41
(t, J＝8.0 Hz, 1H), 7.53 (t, J＝8.0 Hz, 2H), 8.12 (d, J＝
8.0 Hz, 2H), 8.29 (s, 1H), 10.94 (s, 1H), 13.42 (br s, 1H);
13C NMR (DMSO, 100 MHz) δ: 10.5, 18.7, 118.9,
128.2, 129.3, 134.5, 139.2, 144.2, 150.1, 153.0, 161.9;
IR (KBr) v: 3421, 2972, 2252, 2126, 1658, 1452, 1379,
－
1
1027, 762 cm . Anal. calcd for C14H14N6S: C 56.36, H
4.73, N 28.17; found C 56.34, H 4.70, N 28.15.
5-Phenyl-4-[(2-phenyl-2H-1,2,3-triazol-4-yl)me-
thyleneamino]-4H-1,2,4-triazole-3-thiol (L2) Yellow
1
solid, m.p. 195—197 ℃; H NMR (DMSO, 400 MHz)
δ: 7.42 (t, J＝6.8 Hz, 1H), 7.48—7.56 (m, 5H), 7.93 (d,
J＝8.0 Hz, 2H), 8.13 (d, J＝8.0 Hz, 2H), 8.28 (s, 1H),
10.59 (s, 1H), 10.64 (s, 1H); 13C NMR (CDCl3, 100
MHz) δ: 119.2, 125.0, 128.4, 128.6, 128.8, 129.4, 131.0,
135.0, 139.3, 143.7, 150.1, 154.0, 163.0; IR (KBr) v:
3101, 2939, 2757, 1594, 1491, 1450, 1375, 1259, 934,
－
1
763, 687 cm . Anal. calcd for C18H14N6S: C 62.41, H
4.07, N 24.26; found C 62.38, H 4.01, N 24.23.
2-[(2-Phenyl-2H-1,2,3-triazol-4-yl)methylene-
amino]phenol (L3) Yellow solid, m.p. 225—227 ℃;
Figure
1
Proposed mechanism of synthesis of
bis(indoly)methane catalyzed by CrCl3•6H2O/hydrogenated
bis-Schiff bases.
Chin. J. Chem. 2011, 29, 2091— 2096
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Yang, Xie & Wang
FULL PAPER
1H NMR (DMSO, 400 MHz ) δ: 6.94 (t, J＝7.6 Hz, 1H),
7.04 (d, J＝8.0 Hz, 1H), 7.19 (br s, 1H, OH), 7.22 (d,
J＝7.2 Hz, 1H), 7.35—7.43 (m, 2H), 7.53 (t, J＝7.2 Hz,
2H), 8.13 (d, J＝8.4 Hz, 2H), 8.35 (s, 1H), 10.22 (s, 1H);
13C NMR (CDCl3, 100 MHz) δ: 115.4, 115.7, 119.0,
120.2, 128.1, 129.4, 129.8, 134.7, 134.8, 139.4, 147.3,
147.4, 152.4; IR (KBr) v: 3326, 1629, 1586, 1481, 1357,
1305, 1215, 962, 752 cm . Anal. calcd for C15H12N4O:
C 68.17, H 4.58, N 21.20.; found C 68.16, H 4.55, N
21.18.
(br s, 2H); IR (KBr) v: 3458, 3053, 2852, 1674, 1593,
－
1
1552, 1505, 1486, 1410, 1245, 1093, 744 cm . Anal.
calcd for C23H17N3O2: C 75.19, H 4.66, N 11.44; found
C 75.18, H 4.64, N 11.49.
3,3'-[(3-Nitrophenyl)methylene]bis(1H-indole)
(3d) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 5.99 (s,
1H), 6.49 (s, 2H), 7.03 (t, J＝8.0 Hz, 2H), 7.20 (t,
J＝7.2 Hz, 2H), 7.37 (t, J＝7.6 Hz, 4H), 7.44 (t, J＝7.6
Hz, 1H), 7.69 (d, J＝7.6 Hz, 1H), 7.97 (s, 2H), 8.08 (d,
J＝7.6 Hz, 1H), 8.21 (br s, 2H); IR (KBr) v: 3455, 3050,
2849, 1670, 1613, 1588, 1501, 1451, 1405, 1090, 741
－
1
2-[(2-Phenyl-2H-1,2,3-triazol-4-yl)methylamino]-
－
1
1
phenol (L4) Pink solid; m.p. 147—149 ℃; H NMR
cm . Anal. calcd for C23H17N3O2: C 75.19, H 4.66, N
(CDCl3, 400 MHz) δ: 4.53 (s, 2H), 4.90 (s, br 1H), 6.68
(t, J＝8.8 Hz, 1H), 6.77 (t, J＝8.8 Hz, 2H), 6.86 (t, J＝
8.8 Hz, 1H), 7.34 (t, J＝7.6 Hz, 1H), 7.48 (t, J＝7.6 Hz,
2H), 7.73 (s, 1H), 8.05 (d, J＝7.6 Hz, 2H); 13C NMR
(CDCl3, 100 MHz) δ: 40.3, 113.1, 114.5, 118.6, 118.7,
121.7, 127.4, 129.3, 134.3, 136.2, 143.9, 148.0; IR (KBr)
11.44; found C 75.14, H 4.63, N 11.56.
3,3'-[(4-Fluorophenyl)methylene]bis(1H-indole)
(3e) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 5.87 (s,
1H), 6.62 (s, 2H), 6.96 (t, J＝8.0 Hz, 2H), 7.02 (t, J＝
8.0 Hz, 2H), 7.19 (t, J＝7.2 Hz, 2H), 7.28—7.31 (m,
2H), 7.36 (t, J＝7.2 Hz, 4H), 7.89 (br s, 2H); IR (KBr) v:
3410, 3052, 2920, 1617, 1510, 1455, 1337, 1901, 743
－
1
v: 3420, 3320, 1629, 1586, 1357, 1215, 942, 752 cm .
Anal. calcd for C15H14N4O: C 67.65, H 5.30, N 21.04;
found C 67.63, H 5.25, N 21.02.
－
1
cm . Anal. calcd for C23H17FN2: C 81.16, H 5.03, N
8.23; found C 81.14, H 4.99, N 8.20.
N1,N3-Bis[(2-Phenyl-2H-1,2,3-triazol-4-yl)methyl-
ene]propane-1,3-diamine (L5) White solid; m.p. 107
3,3'-[(4-Chlorophenyl)methylene]bis(1H-indole)
(3f) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 5.86 (s,
1H), 6.66 (s, 2H), 7.02 (t, J＝8.2 Hz, 2H), 7.18 (t, J＝
7.8 Hz, 2H), 7.23—7.28 (m, 4H), 7.36 (d, J＝7.2 Hz,
4H), 7.93 (br s, 2H); IR (KBr) v: 3411, 3054, 2922,
1
—108 ℃; H NMR (CDCl3, 400 MHz) δ: 2.14—2.22
(m, 2H), 3.79 (t, J＝8.0 Hz, 4H), 7.36—8.10 (m, 10H),
8.20 (s, 2H), 8.54 (s, 2H); IR (KBr) v: 3065, 2896, 1622,
－
－
1
1
1596, 1489, 962, 743 cm . Anal. calcd for C21H20N8: C
65.61, H 5.24, N 29.15; found C 65.73, H 5.13, N 29.14.
N1,N3-Bis[(2-Phenyl-2H-1,2,3-triazol-4-yl)me-
1617, 1509, 1454, 1336, 1901, 741 cm . Anal. calcd
for C23H17ClN2: C 77.41, H 4.80, N 7.85; found C 77.39,
H 4.87, N 7.81.
1
thyl]propane-1,3-diamine (L6) Yellow liquid; H
3,3'-[(4-Bromophenyl)methylene]bis(1H-indole)
(3g) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 5.85 (s,
1H), 6.62 (s, 2H), 7.03 (t, J＝8.0 Hz, 2H), 7.18—7.23
(m, 4H), 7.35—7.42 (m, 6H), 7.86 (br s, 2H); IR (KBr)
v: 3412, 3056, 1618, 1550, 1485, 1417, 1338, 1217,
NMR (CDCl3, 400 MHz) δ: 0.84 (m, 2H), 1.26 (t, J＝
8.0 Hz, 4H), 2.51 (br s, 2H), 4.86 (s, 4H), 7.29 (t, J＝8.4
Hz, 2H), 7.48 (t, J＝8.4 Hz, 4H), 7.76 (s, 2H), 8.01 (d,
J＝7,6 Hz, 4H); 13C NMR (CDCl3, 100 MHz) δ: 10.33,
22.08, 56.6, 118.7, 127.5, 129.2, 134.1, 139.6, 149.0; IR
(KBr) v: 3235, 2940, 1743, 1689, 1595, 1491, 1352,
－
1
1093, 740 cm . Anal. calcd for C23H17BrN2: C 68.84,
H 4.27, N 6.98; found C 68.93, H 4.28, N 6.89.
－
1
1229, 963, 759, 658 cm . Anal. calcd for C21H24N8: C
64.93, H 6.23, N 28.84; found C 64.92, H 6.20, N 28.80.
3,3'-[(2,4-Dichlorophenyl)methylene]bis(1H-
indole) (3h) Red solid; 1H NMR (CDCl3, 400 MHz) δ:
6.28 (s, 1H), 6.59 (s, 2H), 7.06 (t, J＝8.2 Hz, 3H), 7.15
(d, J＝8.2 Hz, 1H), 7.20 (t, J＝7.2 Hz, 2H), 7.35—7.40
(m, J＝9.6 Hz, 4H), 7.45 (s, 1H), 7.87 (br s, 2H); IR
(KBr) v: 3413, 3059, 2870, 1617, 1580, 1487, 1456,
1416, 1337, 1216, 1095, 745 cm－ 1. Anal. calcd for
C23H16Cl2N2: C 70.60, H 4.12, N 7.16; found C 70.50, H
4.13, N 7.24.
2-[Di(1H-indol-3-yl)methyl]phenol (3i) Red solid;
1H NMR (CDCl3, 400 MHz) δ: 6.18 (s, 1H), 6.91 (s,
2H), 7.03 (t, J＝7.8 Hz, 2H), 7.19 (t, J＝7.8 Hz, 2H),
7.31 (t, J＝6.8 Hz, 1H), 7.37 (d, J＝7.8 Hz, 2H), 7.42—
7.51 (m, 4H), 8.00 (br s, 2H), 8.06 (d, J＝7.6 Hz, 2H);
IR (KBr) v: 3413, 3058, 2935, 1672, 1602, 1521, 1459,
1339, 1275, 1214, 1122, 743 cm－ 1. Anal. calcd for
C23H18N2O: C 81.63, H 5.36, N 8.28; found C 81.60, H
5.33, N 8.30.
3,3'-(Phenylmethylene)bis(1H-indole)
(3a)
1
Colorless solid; H NMR (CDCl3, 400 MHz) δ: 5.87 (s,
1H), 6.65 (s, 2H), 7.00 (t, J＝6.8 Hz, 2H), 7.13—7.23
(m, 3H), 7.26—7.30 (m, 2H), 7.33—7.43 (m, 6H), 7.91
(br s, 2H); IR (KBr) v: 3424, 3077, 2852, 1674, 1631,
－
1
1528, 1473, 1436, 1355, 1260, 1112 ,1030, 750 cm .
Anal. calcd for C23H18N2: C 85.68, H 5.63, N, 8.69;
found C 85.57, H 5.59, N 8.77.
3,3'-[(4-Nitrophenyl)methylene]bis(1H-indole)
(3b) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 5.99 (s,
1H), 6.69 (s, 2H), 7.03 (t, J＝8.0 Hz, 3H), 7.34 (d, J＝
8.0 Hz, 2H), 7.40 (d, J＝8.0 Hz, 2H), 7.52 (d, J＝8.8 Hz,
2H) 8.01 (br s, 2H), 8.14 (d, J＝8.8 Hz, 2H); IR (KBr) v:
3459, 3054, 2852, 1674, 1592, 1505, 1456, 1410, 1336,
－
1
1245, 1093, 744 cm . Anal. calcd for C23H17N3O2: C
75.19, H 4.66, N 11.44; found C 75.28, H 4.63, N 11.49.
3,3'-[(2-Nitrophenyl)methylene]bis(1H-indole) (3c)
4-[Di(1H-indol-3-yl)methyl]phenol (3j) Red solid;
1H NMR (CDCl3, 400 MHz) δ: 4.60 (s, 1H), 5.83 (s,
1H), 6.66 (s, 2H), 6.75 (d, J＝8.4 Hz, 2H), 7.01 (t, J＝
8.4 Hz, 3H), 7.15—7.22 (m, 4H), 7.36—7.40 (m, 4H),
1
Red solid; H NMR (CDCl3, 400 MHz) δ: 6.67 (s, 1H),
6.68 (s, 2H), 7.03 (t, J＝8.0 Hz, 2H), 7.18 (t, J＝8.0 Hz,
2H), 7.35—7.43 (m, 7H), 7.85 (d, J＝7.6 Hz, 1H), 7.96
2094
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Chin. J. Chem. 2011, 29, 2091— 2096

CrCl3•6H2O/Hydrogenated Bis-Schiff Base as a New Efficient Catalyst System
－
1
7.92 (br s, 2H); IR (KBr) v: 3412, 3058, 2870, 1614,
cm . Anal. calcd for C25H19N5: C 77.10, H 4.92, N
17.98; found C 77.09, H 4.90, N 17.97.
－
1
1579, 1487, 1456, 1416, 1336, 1216, 1095, 744 cm .
Anal. calcd for C23H18N2O: C 81.63, H 5.36, N 8.28;
found C 81.59, H 5.38, N 8.16.
3,3'-[(4-Methyl-1-phenyl-1H-pyrazol-3-yl)methyl-
ene]bis(1H-indole) (3q)
Yellow solid; 1H NMR
3,3'-(p-Tolylmethylene)bis(1H-indole) (3k) Red
solid; 1H NMR (CDCl3, 400 MHz) δ: 2.32 (s, 3H), 5.85
(s, 1H), 6.65 (s, 2H), 7.02 (t, J＝7.0 Hz, 2H), 7.08 (d,
J＝7.0 Hz, 2H), 7.17 (t, J＝7.2 Hz, 3H), 7.23 (d, J＝8.0
Hz, 2H), 7.34 (d, J＝7.0 Hz, 2H), 7.39 (d, J＝7.0 Hz,
2H), 7.88 (br s, 2H); IR (KBr) v: 3412, 3057, 1603,
(CDCl3, 400 MHz) δ: 2.05 (s, 3H), 5.93 (s, 1H), 6.78 (s,
2H), 7.05 (t, J＝7.6 Hz, 2H), 7.19 (t, J＝7.6 Hz, 2H),
7.35—7.46 (m, 7H), 7.58 (d, J＝8.4 Hz, 2H), 8.0 (br s,
2H); 13C NMR (DMSO, 100 MHz) δ: 13.5, 29.9, 116.8,
119.3, 119.7, 122.0, 123.4, 124.8, 126.9, 128.9, 136.6,
149.0; IR (KBr) v: 3404, 2943, 1650, 1518, 1440, 1001,
－
－
1
1
1549, 1506, 1456, 1338, 1217, 1156, 1094, 746 cm .
Anal. calcd for C24H20N2: C 85.68, H 5.99, N 8.33;
found C 85.69, H 5.87, N 8.42.
748 cm . Anal. calcd for C27H21ClN4: C 74.22, H 4.84,
N 12.82; found C 74.18, H 4.90, N 12.79.
4-[Di(1H-indol-3-yl)methyl]-2-methoxyphenol (3l)
Red solid; H NMR (CDCl3, 400 MHz) δ: 3.76 (s, 3H),
References
1
1
(a) Lo, K. K.-W.; Tsang, K. H.-K.; Hui, W.-K.; Zhu, N.
Chem. Commun. 2003, 21, 2704.
5.51 (br s, 1H), 5.82 (s, 1H), 6.65 (s, 2H), 6.82 (s, H),
6.89 (s, 1H), 7.01 (t, J＝7.2 Hz, 2H), 7.17 (t, J＝7.2 Hz,
2H), 7.35 (d, J＝8.0 Hz, 2H), 7.40 (d, J＝8.0 Hz, 2H),
7.91 (br s, 2H); IR (KBr) v: 3411, 2929, 2849, 1670,
(b) Sobhani, S.; Safaei, E.; Hasaninejad, A. R.; Rezazadeh,
S. J. Organomet. Chem. 2009, 694, 3027.
(c) Li, J. T.; Dai, H. G.; Xu, W. Z.; Li, T. S. Ultrason.
Sonochem. 2006, 13, 24.
－
1
1599, 1509, 1456, 1338, 1270, 1032, 743 cm . Anal.
calcd for C24H20N2O2: C 78.24, H 5.47, N 7.60; found C
78.21, H 5.42, N 7.57.
(d) Sadaphal, S. A.; Kategaonkar, A. H.; Labade, V. B.;
Shingare, M. S. Chin. Chem. Lett. 2010, 21, 39.
Azizian, J.; Teimouri, F.; Mohammadizadeh, M. R. Catal.
Commun. 2007, 8, 1117.
(a) Ma, S. M.; Yu, S. C. Org. Lett. 2005, 7, 5063.
(b) Noland, W. E.; Venkiteswaran, M. R.; Richards, C. G. J.
Org. Chem. 1961, 26, 4241.
3,3'-[(4-Methoxyphenyl)methylene]bis(1H-indole)
1
2
3
(3m) Red solid; H NMR (CDCl3, 400 MHz) δ: 5.84
(s, 1H), 6.64 (s, 2H), 6.82 (d, J＝8.8 Hz, 2H), 6.99 (t,
J＝7.2 Hz, 2H), 7.16 (t, J＝7.2 Hz, 2H), 7.25 (d, J＝8.8
Hz, 2H), 7.34 (d, J＝7.6 Hz, 2H), 7.38 (d, J＝7.6 Hz,
2H), 7.89 (br s, 2H); IR (KBr) v: 3403, 2947, 1654,
－
1
4
(a) He, X.; Hu, S.; Liu, K.; Guo, Y.; Xu, J.; Shao, S. Org.
Lett. 2006, 8, 333.
1611, 1587, 1509, 1455, 1336, 1243, 1010, 740 cm .
Anal. calcd for C24H20N2O: C 81.79, H 5.72, N 7.95;
found C 81.77, H 5.69, N 7.71.
(b) Chen, D. P.; Yu, L.; Wang, B. P. G. Tetrahedron Lett.
1996, 37, 4467.
(c) Yadav, J. S.; Subba Reddy, B. V.; Satheesh, G. Tetrahe-
dron Lett. 2004, 45, 3673.
3,3'-[(2-Methoxyphenyl)methylene]bis(1H-indole)
(3n) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 3.83 (s,
3H), 6.36 (s, 1H), 6.66 (s, 2H), 6.93—7.02 (m, 4H),
7.13—7.18 (m, 4H), 7.37 (d, J＝8.0 Hz, 2H), 7.41 (d,
J＝8.0 Hz, 2H), 7.99 (br s, 2H); IR (KBr) v: 3411, 2931,
5
6
7
8
9
Feng, X. L.; Guan, C. J.; Zhao, C. X. Synth. Commun. 2004,
34, 487.
Chen, D.; Yu, L.; Wang, P. G. Tetrahedron Lett. 1996, 37,
4467.
Sharma, G. V. M.; Reddy, J. J.; Lakshmi, P. S.; Krishna, P.
R. Tetrahedron Lett. 2004, 45, 7729.
Firouzabadi, H.; Iranpoor, N.; Jafarpour, M.; Ghaderi, A. J.
Mol. Catal. A: Chem. 2006, 253, 249.
－
1
1617, 1597, 1488, 1456, 1337, 1241, 1091, 741 cm .
Anal. calcd for C24H20N2O: C 81.79, H 5.72, N 7.95;
found C 81.75, H 5.69, N 7.79.
4-[Di(1H-indol-3-yl)methyl]-N,N-dimethylaniline
(3o) Red solid; 1H NMR (CDCl3, 400 MHz) δ: 2.91 (s,
6H), 5.80 (s, 1H), 6.67 (m, 4H), 6.99 (t, J＝8.4 Hz, 2H),
7.15 (t, J＝8.0 Hz, 2H), 7.20 (d, J＝8.4 Hz, 2H,), 7.35
(d, J＝8.0 Hz, 2H), 7.41 (d, J＝8.0 Hz, 2H), 7.89 (br s,
2H); IR (KBr) v: 3406, 2923, 1774, 1725, 1612, 1517,
1456, 1339, 1217, 1010, 744 cm－ 1. Anal. calcd for
C25H23N3: C 82.16, H 6.34, N 11.50; found C 82.11, H
6.30, N 11.45.
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Kunwar, A. C. Tetrahedron Lett. 2003, 44, 2221.
11 Bandgar, B. P.; Shaikh, K. A. Tetrahedron Lett. 2003, 44,
1959.
12 Sato, S.; Sato, T. Carbohydr. Res. 2005, 340, 2251.
13 Zolfigol, M. A.; Salehi, P.; Shiri, M.; Tanbakouchian, Z.
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Lett. 2010, 51, 1213.
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3,3'-[(2-Phenyl-2H-1,2,3-triazol-4-yl)methylene]-
1
bis(1H-indole) (3p) Red solid; H NMR (CDCl3, 400
MHz,) δ: 6.18 (s, 1H), 6.92 (s, 2H), 7.03 (t, J＝7.2 Hz,
2H), 7.18 (t, J＝7.6 Hz, 2H), 7.32 (t, J＝7.2 Hz, 1H),
7.37 (d, J＝8.4 Hz, 2H), 7.43—7.52 (m, 4H), 7.58 (s,
1H), 8.00 (br s, 2H), 8.05 (d, J＝8.0 Hz, 2H); 13C NMR
(CDCl3, 100 MHz) δ: 40.38, 111.24, 116.93, 119.43,
119.89, 120.14, 122.12, 123.82, 126.34, 127.27, 128.43,
128.93, 132.23, 136.87, 144.19; IR (KBr) v: 3411, 3057,
2926, 1722, 1618, 1598, 1457, 1338, 1095, 967, 742
16 Patel, S. A.; Sinha, S.; Mishra, A. N.; Kamath, B. V.; Ram,
R. N. J. Mol. Catal. A: Chem. 2003, 192, 53.
17 Kureshy, R. I.; Khan, N. H.; Abdi, S. H. R.; Patel, S. T.;
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© 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
2095

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FULL PAPER
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(E1104181 Lu, Y.)
2096
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© 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2011, 29, 2091— 2096