Synthesis and crystal structure of 4,7-diaryl-5-oxo-4H-benzo[b]pyran derivatives

Article abstract of DOI:10.1002/jhet.895

A green and convenient approach to the synthesis of a series of 4,7-diaryl-5-oxo-4H-benzo[b]pyran derivatives from appropriate aromatic aldehydes and 5-aryl-1,3-cyclohexanedione with malononitrile in the presence of dilute HCl as catalyst (30 mmol/L) is described. This method provides several advantages such as environmental friendliness, low cost, high yields, and simple work up procedure. The structures of all compounds were characterized by infrared (IR), mass spectrometry (MS), ¹H NMR, and elemental analysis. The crystal structure of trans/cis-2-amino-3-cyano-7-(4'-methoxo- phenyl)-4-phenyl-5-oxo-4H-benzo[b]pyran, g, was determined by single crystal X-ray diffraction analysis. The crystal of compound g belongs to monoclinic with space group P 21/c, a = 8.477(3) nm, b = 18.948(6) nm, c = 24.915(7) nm, α = 90.00°, β = 107.388(11)°, γ= 90.00°, Z = 8, V = 3.819(2) nm³, R₁ = 0.0754, wR₂ = 0.2042.

Full text of DOI:10.1002/jhet.895

900
Synthesis and Crystal Structure of 4,7-Diaryl-5-oxo-4H-
benzo[b]pyran Derivatives
Vol 49
*
Bin Cui, Li-Zhuang Chen, Xiao-Lei Hu, Ming Wang, and Guang-Fan Han
Applied Chemistry, School of Biological and Chemical Engineering, Jiangsu University of Science and Technology,
Zhenjiang, Jiangsu 212003, China
*
E-mail: gf552002@yahoo.com.cn
Received January 19, 2011
DOI 10.1002/jhet.895
View this article online at wileyonlinelibrary.com.
O
R
R
CN
CN
O
O
H2O
H
CHO
H
+
+
+
CN
NH2
R
CN
NH2
dilute HCl
O
Ar
Ar
O
H
O
H
Ar
2
5a~5p
1
3
4a~4p
A green and convenient approach to the synthesis of a series of 4,7-diaryl-5-oxo-4H-benzo[b]pyran
derivatives from appropriate aromatic aldehydes and 5-aryl-1,3-cyclohexanedione with malononitrile in
the presence of dilute HCl as catalyst (30 mmol/L) is described. This method provides several advantages
such as environmental friendliness, low cost, high yields, and simple work up procedure. The structures
1
of all compounds were characterized by infrared (IR), mass spectrometry (MS), H NMR, and elemental
analysis. The crystal structure of trans/cis-2-amino-3-cyano-7-(40-methoxo-phenyl)-4-phenyl-5-oxo-4H-
benzo[b]pyran, g, was determined by single crystal X-ray diffraction analysis. The crystal of compound
g belongs to monoclinic with space group P 21/c, a = 8.477(3) nm, b = 18.948(6) nm, c = 24.915(7)
nm, a = 90.00ꢀ, b = 107.388(11)ꢀ, g= 90.00ꢀ, Z = 8, V = 3.819(2) nm3, R1 = 0.0754, wR2 = 0.2042.
J. Heterocyclic Chem., 49, 900 (2012).
INTRODUCTION
HCl (30 mmol/L) as a reusable, inexpensive, and effi-
cient catalyst in a solvent-free media.
Benzopyran, as the parent ring of many natural
products, is widely found in the nature. Its derivatives
have been approved to possess good biological activity
and also exhibit antitumoractivity, desensitization,
antispasmodic, diuresis, and so on. In addition, benzo-
pyran derivatives could serve as the moderators for the
potassium ion channel [1–3].
Recently, the synthesis of benzopyran has received
much more attention. Various methods have been
reported for the synthesis of benzopyran, among which
the conventional method for the synthesis of benzopyran
is the azeotropic removal of water by refluxing aromatic
aldehydes and 5,5-dimethyl-1,3-cyclohexanedione with
malononitrile [4]. Several other improved methods for
the preparation of benzopyran have been reported to use
microwaves [5,6] in distinct solution including Ac2O
[7], Acetonitrile–Ac2O [8], toluene [9], dichloromethane
[10], and so on.
However, most of the methods suffer from certain
drawbacks such as long reaction time, unsatisfactory
yields, expensive catalysts, hazardous solvents, complex
process, low selectivity, co-occurrence of several
side reactions, and needing of chromatography for puri-
fication of adducts. In this article, we report here, a
simple procedure and high efficient synthesis of
benzopyran starting from 5-aryl-1,3-cyclohexanedione
and aromatic aldehydes with malononitrile using dilute
RESULT AND DISCUSSION
The synthetic route was shown in Scheme 1. A series
of 4,7-diaryl-5-oxo-4H-benzo[b]pyran derivatives were
prepared from appropriate aromatic aldehydes and 5-
aryl-1,3-cyclohexanediones with malononitrile in the
presence of dilute HCl as catalyst in water. As shown in
Table 1, the reaction proceeded smoothly to afford the
corresponding products in good yields. Most importantly,
aromatic aldehydes bearing either electron-donating or
electron-withdrawing substituents reacted very well to
afford the corresponding 4H-benzo[b]pyran derivatives
in moderate to excellent yields with high purity.
To optimize the effect of the catalyst on the reaction, we
increased the amount of catalyst gradually. It was found
that the reaction was difficult to carry out without the cata-
lyst, and while using two drops of concentrated HCl (about
0.1 mL) in 40 mL of water at 70–80ꢀC for 2 h, the reaction
could afford the corresponding products in good yields.
But with the catalyst increased, the yields show a decreas-
ing trend. These data indicated that two drops of concen-
trated HCl in 40 mL of water is quite suitable for this
reaction.
Each of the compounds should be as a diastereomeric
mixture because of the two chiral carbon atoms 4-C and
© 2012 HeteroCorporation

July 2012
Synthesis and Crystal Structure of 4,7-Diaryl-5-oxo-4H-benzo[b]pyran Derivatives
901
Scheme 1
O
O
O
NaOH
H+
CH2(COOEt)2
NaOEt ,
Ar CHO
O
+
Ar
O
Ar
R
R
CN
CN
O
O
H2O
dilute HCl
H
CHO
H
+
+
+
CN
R
CN
NH2
O
Ar
Ar
O
NH2
H
O
H
Ar
2
5a~5p
1
3
4a~4p
a: Ar=C6H5, R=H;
b: Ar=C6H5, R=4-Cl;
e: Ar=C6H5, R=3-NO2;
h: Ar=4-OCH3C6H4, R=4-Cl;
k: Ar=4-OCH3C6H4, R=2-Cl;
n: Ar=2-furyl, R=3,4-(OCH3)2;
c: Ar=C6H5, R=3,4-(OCH3)2;
f: Ar=C6H5, R=4-Cl;
i: Ar=4-OCH3C6H4, R=3,4-(OCH3)2;
l: Ar=4-OCH3C6H4, R=3-NO2;
o: Ar=2-furyl, R=2-Cl;
d: Ar=C6H5, R=4-OCH3;
g: Ar=4-OCH3C6H4, R=H;
j: Ar=4-OCH3C6H4, R=4-OCH3;
m: Ar=2-furyl, R=H;
p: Ar=2-furyl, R=4-OCH3;
1
7-C. The data of H NMR, MS, and IR as shown in the
experimental section are in accordance with the chemical
structures of the target compounds. All standard adducts
comprised a pair of epimers such as 4a and 5a and their
certain chemical shifts appeared in pairs in distinct intensi-
ties. In the 1H NMR spectrum of compounds 4a and 5a, the
two broad single proton peaks at 4.65 and 4.68, which are
equal to two H and disappeared after D2O exchanging,
were attributed to the two N―H of the amino group. The
chemical shifts of the protons linked in C4-position were
found at d 4.46 and 4.48 ppm, whereas the two gem-carbon
protons of C6- and C8-position appeared at d2.80–2.99
and 2.54–2.71 ppm, respectively. The two heptet peaks at
3.48–3.53 are equal to one H corresponding to the proton
attached to C7-position. According to this dates, we
concluded that the compounds should be as a diastereo-
meric mixture.
The structures of these compounds were further sup-
ported by their IR spectra. Several typical absorption bands
at 1604 cmꢁ1 for (C¼O), 2196 cmꢁ1 for (CꢂN), and 3383
cmꢁ1 for (N―H) were observed, respectively.
CRYSTAL STRUCTURE
A summary of the crystal data and structure refinement
is presented in Table 2. A perspective view of compound
g with atomic numbering scheme was shown in Figure 1.
In the crystal structure of compound g, the central cyclo-
hexyl ring in the chromene core shows a half-boat confor-
mation. Because of the two chiral carbon atoms [C(7) or
Table 1
Synthesis of 4,7‐diaryl‐5‐oxo‐4H‐benzo[b]pyran derivatives.
Entry
Ar
R
M.P. (°C)
Yield (%)
Approximate ratio (4:5)a
4a+5a
4b+5b
4c+5c
4d+5d
4e+5e
4f+5f
4g+5g
4h+5h
4i+5i
4j+5j
4k+5k
4l+5l
4m+5m
4n+5n
4o+5o
4p+5p
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
4‐OCH3C6H4
4‐OCH3C6H4
4‐OCH3C6H4
4‐OCH3C6H4
4‐OCH3C6H4
4‐OCH3C6H4
2‐furyl
H
4‐Cl
3,4‐(OCH3)2
4‐OCH3
3‐NO2
2‐Cl
178–180
202–204
188–189
212–214
194–196
176–178
199–201
236–238
212–213
168–170
170–172
222–224
180–182
192–194
198–200
202–204
85
82
91
87
80
85
89
79
83
84
82
90
82
85
86
88
55:45
67:33
65:35
62:38
47:53
58:42
54:46
64:36
61:39
57:43
58:42
45:55
52:48
63:37
61:39
60:40
H
4‐Cl
3,4‐(OCH3)2
4‐OCH3
2‐Cl
3‐NO2
H
3,4‐(OCH3)2
2‐Cl
4‐OCH3
2‐furyl
2‐furyl
2‐furyl
1
aIt was speculated from the integration area of the special position H in the H NMR spectrum.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

902
B. Cui, L.-Z. Chen, X.-L. Hu, M. Wang, and G.-F. Han
Vol 49
Table 2
Crystallographic data for complex g.
CONCLUSION
In summary, we described an efficient, environmentally
friendly, and convenient method for the synthesis of
benzopyran by treatment of 5-aryl-1,3-cyclohexanedione,
aromatic aldehydes, and malononitrile with dilute HCl
(30 mmol/L) as catalyst in a solvent-free media. Moreover,
the procedure possesses several advantages such as high
yields, low cost, simple operation, clean reactions, and
minimal environmental effects. We expect the procedure
to be used for large-scale, eco-friendly preparation for
these compounds.
Empirical formula
Formula weight
C23H20N2O3
372.41
Wavelength (nm)
0.071073
Crystal system
Monoclinic
Space group
a (nm)
b (nm)
P 21/c
8.477 (3)
18.948 (6)
24.915 (7)
90.00
107.388 (11)
90.00
3.819 (2)
c (nm)
a (ꢀ)
b (ꢀ)
g (ꢀ)
Volume (nm3)
Z
8
EXPERIMENTAL
Calculated density (g cmꢁ3
)
1.295
0.087
Absorption coefficient (mmꢁ1
)
Melting points were determined on an electrothermal apparatus
and uncorrected. Microanalysis was performed on Perkin-Elmer
2400 Microanalytical Service. IR spectra were recorded on a
Perking-Elmer 1700 spectrophotometer. The 1H NMR was
obtained (CDCl3, d 7.27ppm) from a Bruker ARX-300 spectrom-
eter. Mass spectra were recorded on JMS-DX300 at 70 eV.
All chemical reagents were commercially available and
purified with standard operation before use. Solvents were dried
in routine ways and redistilled. 5-Aryl-1,3-cyclohexanedione
was obtained from aromatic aldehyde, acetone, and diethyl
malonate, according to the literature [11] method with slight
modification.
F (000)
1568
Final R indices [I > 2 sigma(I)]
R indices (all data)
R1 = 0.0754, wR2 = 0.2042
R1 = 0.1456, wR2 = 0.2338
C(30), C(13), or C(36)] in the molecules, there exist two
isomer molecules in an asymmetric unit. In one molecule,
the configurations of C(7) and C(13) are Sinister and
Rectus, respectively, and the dihedral angles between
the cyclohexyl ring and the two outer phenyl rings
are 87.32 (11)ꢀ and 52.64 (10)ꢀ. However, the
configurations of C(30) and C(36) in the other molecular
are Rectus and Sinister, respectively, and its dihedral
angles are 72.48 (11)ꢀ and 53.56 (13)ꢀ. The packing
diagram of the g in a unit cell was shown in Figure 2.
X-ray analysis reveals that there are intramolecular and
intermolecular hydrogen bonds in the crystal. The length
of intermolecular hydrogen bonds, N(1)-H(1BꢃꢃꢃN(4), N(1)-
H(1CꢃꢃꢃO(3), N(3)-H(3BꢃꢃꢃN(2), and N(3)-H(3CꢃꢃꢃO(2)
are 2.16 Å, 2.37 Å, 2.30 Å, and 3.030 Å, respectively.
The structural analysis indicates that these molecular
interactions play the role of further stabilizing the
structure. The bond lengths and bond angles of primary
hydrogen bonds were listed in Table 3.
General procedure. A mixture of aromatic aldehydes (1, 5
mmol), 5-aryl-1,3-cyclohexanedione (2, 5 mmol), malononitrile
(3, 5 mmol), and 30 mmol/L dilute hydrochloric acid (40 mL)
was stirred at 70–80ꢀC for 2 h. Then the mixture was cooled to
room temperature and then the solid was collected and washed
with water. The crude products were recrystallized from ethanol
(95%).
Data of compounds are shown below.
4a+5a 1H NMR
(CDCl3, 300 MHz) d: 2.54–2.71 (m, 2H, 8-H), 2.80–2.99 (m,
2H, 6-H), 3.48–3.53 (m, 1H, 7-H), 4.46 and 4.48 (each s, 1H,
4-H), 4.65 and 4.68 (each s, 2H, N―H), 7.17–7.37 (m, 10H,
Ph-H). IR (KBr) n: 3383, 3255, 2196, 1683, 1604, 1489, 1454
cmꢁ1; MS (70 eV) m/z (%): 343.2(M++1, 100). Anal. calcd for
C22H18N2O2: C 77.17, H 5.30, N 8.18; found C 77.27, H 5.35,
N 8.24.
1
4b+5b H NMR (CDCl3, 300 MHz) d: 2.58–2.73 (m, 2H, 8-
H), 2.83–2.98 (m, 2H, 6-H), 3.35–3.58 (m, 1H, 7-H), 4.43 and
4.44 (each s, 1H, 4-H), 4.64 and 4.66 (each s, 2H, N―H),
7.10–7.46 (m, 9H, Ph-H). IR (KBr) n: 3395, 3251, 2200, 1670,
1604, 1492, 1413cmꢁ1. MS (70 eV) m/z (%): 399.6 (M++Na,
100). Anal. calcd for C22H17ClN2O2: C 70.12, H 4.55, N 7.43;
found C 70.07, H 4.45, N 7.35.
4c+5c 1H NMR (CDCl3, 300 MHz) d: 2.54–2.72 (m, 2H, 8-H),
2.83–2.90 (m, 2H, 6-H), 3.32–3.49 and 3.50–3.59 (each m, 1H, 7-
H), 3.84 and 3.86 (each s, 3H, OCH3), 3.95 and 3.99 (each s, 3H,
OCH3), 4.43 and 4.45 (each s, 1H, 4-H), 4.55 and 4.57 (each s,
2H, N―H), 6.69–7.17 (m, 8H, Ph-H). IR (KBr) n: 3376, 3259,
2195, 1681, 1605, 1480, 1456 cmꢁ1. MS (70eV) m/z (%): 425.7
(M++Na, 100). Anal. calcd for C24H22N2O4: C 71.63, H 5.51, N
6.96; found C 71.57, H 5.44, N 7.04.
4d+5d 1H NMR (CDCl3, 300 MHz) d: 2.53–2.72 (m, 2H, 8-H),
2.75–2.95 (m, 2H, 6-H), 3.28–3.37 and 3.46–3.52 (each m, 1H,
Figure 1. Packing diagram of compound g in unit-cell.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

July 2012
Synthesis and Crystal Structure of 4,7-Diaryl-5-oxo-4H-benzo[b]pyran Derivatives
903
Figure 2. Molecular structure of compound g.
Table 3
Intermolecular and intramolecular interaction distances (Å) and the bond angle (°) of compound g.
D–H···A
D–H
H···A
D···A
D–H···A
Symmetry
N(1)‐H(1B)···N(4)
0.86
0.86
0.86
0.86
2.16
2.37
2.30
2.14
2.943(5)
3.030(4)
3.039(5)
2.980(4)
151.0
134.2
143.8
165.6
−x+1, y−1/2, −z+1/2
−x+1, −y+1, −z; c−x+1
−x+1, y+1/2, −z+1/2
x, −y+1/2, z+1/2
N(1)‐H(1C)···O(3)
N(3)‐H(3B)···N(2)
N(3)‐H(3C)···O(2)
4h+5h 1H NMR (CDCl3, 300 MHz) d: 2.63–2.92 (m, 4H, 8-H
+6-H), 3.18–3.31 (m, 1H, 7-H), 3.69 and 3.70 (each s, 3H,
OCH3), 4.23 and 4.25 (each s, 1H, 4-H), 4.49 and 4.51 (each s,
2H, N―H), 7.12–7.39 (m, 8H, Ph-H). IR (KBr) n: 3301, 3242,
2188, 1608, 1512, 1458 cmꢁ1. MS (70 eV) m/z (%): 406.1 (M+,
100). Anal. calcd for C29H19ClN2O3: C 67.90, H 4.71, N 8.71;
found C 67.81, H 4.78, N 8.64.
7-H), 3.78 and 3.79(each s, 3H, OCH3), 4.42 and 4.44 (each s, 1H,
4-H), 4.58 and 4.61 (each s, 2H, N―H), 6.79–7.33 (m, 9H, Ph-H).
IR (KBr) n: 3366, 3212, 2185, 1681, 1625, 1490, 1436 cmꢁ1. MS
(70 eV) m/z (%): 373.1 (M++1, 100). Anal. calcd for C23H20N2O3:
C 74.18, H 5.41, N 7.52; found C 74.27, H 5.35, N 7.43.
4e+5e 1H NMR (CDCl3, 300 MHz) d: 2.56–2.70 (m, 2H, 8-H),
2.75–2.87 (m, 2H, 6-H), 3.33–3.49 (m, 1H, 7-H), 4.58 and 4.60
(each s, 1H, 4-H), 4.76 and 4.78 (each s, 2H, N―H), 7.16–8.10
(m, 9H, Ph-H). IR (KBr) n: 3376, 3259, 2195, 1681, 1605,
1480, 1456 cmꢁ1. MS (70 eV) m/z (%): 388.1 (M++1, 100). Anal.
calcd for C22H17N3O4: C 68.21, H 4.42, N 10.85; found C 68.29,
H 4.34, N 10.78.
4f+5f 1H NMR (CDCl3, 300 MHz) d: 2.54–2.71 (m, 2H, 8-H),
2.76–2.91 (m, 2H, 6-H), 3.34–3.41 and 3.42–3.53 (each m, 1H, 7-
H), 4.63 and 4.65 (each s, 1H, 4-H), 4.90 and 4.92 (each s, 2H,
N―H), 7.14–7.40 (m, 9H, Ph-H). IR (KBr) n: 3406, 3249,
2175, 1688, 1623, 1476, 1422 cmꢁ1. MS (70 eV) m/z (%):
377.1 (M++1, 100). Anal. calcd for C22H17ClN2O2: C 70.12, H
4.55, N 7.43; found C 70.19, H 4.62, N 7.36.
4g+5g 1H NMR (CDCl3, 300 MHz) d: 2.60–2.95 (m, 4H, 8-H
+6-H), 3.20–3.35and 3.38–3.55 (m, 1H, 7-H), 3.67 and 3.68
(each s, 3H, OCH3), 4.25 and 4.66 (each s, H, 4-H), 4.45 and
4.47 (each s, 2H, N―H), 6.87 (m, 9H, Ph-H). IR (KBr) n:
3413, 3315, 2176, 1659, 1610, 1511, 1504 cmꢁ1. MS (70 eV)
m/z (%): 372.4 (M+, 100). Anal. calcd for C23H20N2O3: C
74.18, H 5.41, N 7.52; found C 74.27, H 5.35, N 7.46.
1
4i+5i H NMR (CDCl3, 300 MHz) d: 2.65–2.99 (m, 4H, 8-H
+6-H), 3.23–3.45 (m, 1H, 7-H), 3.66 and 3.68 (each s, 3H,
OCH3), 3.71 and 3.73 (each s, 3H, OCH3), 3.73 and 3.75 (each
s, 3H, OCH3), 4.16 and 4.18 (each s, 1H, 4-H), 4.53 and 4.56
(each s, 2H, N―H), 6.57–7.32 (m, 7H, Ph-H). IR (KBr) n:
3314, 3259, 2194, 1605, 1517, 1456 cmꢁ1. MS (70 eV) m/z
(%): 455.8 (M++Na, 100). Anal. calcd for C25H24N2O5:
C 69.43, H 5.59, N 6.48; found C 69.36, H 5.52, N 6.56.
1
4j+5j H NMR (CDCl3, 300 MHz) d: 2.49–2.90 (m, 4H, 8-H
+6-H), 3.28–3.39 and 3.40–3.49 (m, 1H, 7-H), 3.75 and 3.77
(each s, 3H, OCH3), 3.80 and 3.82 (each s, 3H, OCH3), 4.42
and 4.43 (each s, 1H, 4-H), 4.59 and 4.62 (each s, 2H, N―H),
6.58–7.21 (m, 8H, Ph-H). IR (KBr) n: 3352, 3275, 2176, 1665,
1607, 1521, 1502 cmꢁ1. MS (70 eV) m/z (%): 403.2 (M++1,
100). Anal. calcd for C24H22N2O4: C 71.63, H 5.51, N 6.96;
found C 71.57, H 5.45, N 7.03.
4k+5k 1H NMR (CDCl3, 300 MHz) d: 2.49–2.86 (m, 4H, 8-H
+6-H), 3.27–3.49 (m, 1H, 7-H), 3.80 and 3.81 (each s, 3H,
OCH3), 4.62 and 4.63 (each s, 1H, 4-H), 4.89 and 4.91 (each s,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

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B. Cui, L.-Z. Chen, X.-L. Hu, M. Wang, and G.-F. Han
Vol 49
2H, N—H), 6.85–7.31 (m, 8H, Ph-H). IR (KBr) n: 3401, 3282,
2208, 1623, 1522, 1468 cmꢁ1. MS (70 eV) m/z (%): 407.1
(M++1, 100). Anal. calcd for C29H19ClN2O3: C 67.90, H 4.71,
N 8.71; found C 67.98, H 4.78, N 8.65.
3H, OCH3), 4.45 and 4.46 (each s, 1H, 4-H), 4.67 and 4.70
(each s, 1H, N—H), 5.92–5.93 (d, J = 3.21 Hz, 1H, Furyl-
H), 6.32–6.33(d, J = 1.86 Hz, 1H, Furyl-H), 7.073–7.079(d,
J = 1.71 Hz, 1H, Furyl-H), 7.07–7.36 (m, 4H, Ph-H). IR
(KBr) n: 3295, 3212, 2166, 1601, 1508, 1433 cmꢁ1. MS (70
eV) m/z (%): 363.1 (M++Na, 100). Anal. calcd for
C21H18N2O4: C 69.60, H 5.01, N 7.73; found C 69.67, H
4.95, N 7.80.
Determination of crystal structure. A colorless transparent
crystal of size 0.30 ꢄ 0.20 ꢄ 0.20 mm3 was selected for the
crystal structure measurement. The X-ray diffraction intensities
were recorded on a Bruker SMART APEX CCD automatic
diffractometer with graphite-monochromatized Mo Ka radiation
(l = 0.071073 nm) at 291(2)K. In the range of 2.05 < θ <
25.99, 2049 independent reflections were obtained. The
structures were solved by direct methods using SHELXL-97
program. All the nonhydrogen atoms were refined on F2
anisotropically with the full-matrix least squares method.
Hydrogen atoms were added according to the theoretical
methods.
1
4l+5l H NMR (CDCl3, 300 MHz) d: 2.54–2.98 (m, 4H, 8-H
+6-H), 3.27–3.39 and 3.40–3.49 (m, 1H, 7-H), 3.79 and 3.81
(each s, 3H, OCH3), 4.58 and 4.60 (each s, 1H, 4-H), 4.67 and
4.69 (s, 2H, N—H), 6.82–8.11 (m, 8H, Ph-H). IR (KBr) n:
3324, 3253, 2182, 1611, 1526, 1465 cmꢁ1. MS (70 eV) m/z
(%): 418.2 (M++1, 100). Anal. calcd for C23H19N3O5: C 66.18,
H 4.59, N 10.07; found C 66.27, H 4.55, N 10.01.
4m+5m 1H NMR (CDCl3, 300 MHz) d: 2.59–2.97 (m, 4H, 8-
H+6-H), 3.57–3.67 (m, 1H, 7-H), 4.53 and 4.54 (each s, 1H, 4-
H), 4.90 and 4.91 (each s, 2H, N—H), 5.94–5.95(d, J = 3.18
Hz, 1H, Furyl-H), 6.27–6.29(t, J = 2.43 Hz, 1H, Furyl-H),
6.92–6.95(d, J = 4.47 Hz, 1H, Furyl-H), 6.92–7.30 (m, 5H, Ph-
H). IR (KBr) n: 3403, 3333, 2167, 1655, 1601, 1515, 1503
cmꢁ1. MS (70 eV) m/z (%): 333.1 (M++1, 100). Anal. calcd for
C20H16N2O3: C 72.28, H 4.85, N 8.43; found C 72.35, H 4.80,
N 8.37.
4n+5n 1H NMR (CDCl3, 300 MHz) d: 2.52–2.98 (m, 4H, 8-H
+6-H), 3.40–3.51 (m, 1H, 7-H), 3.82 and 3.83 (each s, 3H,
OCH3), 3.88 and 3.89 (each s, 3H, OCH3), 4.20 and 4.18 (each
s, 1H, 4-H), 4.57 and 4.62 (each s, 2H, N—H), 6.07–6.08 (d,
J = 3.12 Hz, 1H, Furyl-H), 6.31–6.33 (t, J = 2.16 Hz, 1H,
Furyl-H), 6.68–6.69 (d, J = 1.89 Hz, 1H, Furyl-H), 6.70–7.36
(m, 3H, Ph-H). IR (KBr) n: 3331, 3232, 2178, 1609, 1515,
1455 cmꢁ1. MS (70 eV) m/z (%): 393.1 (M++1, 100). Anal. calcd
for C22H20N2O5: C 67.34, H 5.14, N 7.14; found C 67.27, H 5.20,
N 7.20.
REFERENCES AND NOTES
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[4] Bao, Z. J.; Ji, S. J.; Lu, J. Chin J Synth Chem 2007, 15, 630.
[5] Tu, S. J.; Gao, Y.; Guo, C. Synth Commun 2002, 14, 2137.
[6] Jpsita, D.; Pulak, J. Tetrahedron Lett 2004, 45, 8625.
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Orga Khim 1976, 12, 663.
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4o+5o 1H NMR (CDCl3, 300 MHz) d: 2.59–2.97 (m, 4H, 8-H
+6-H), 3.49–3.61 (m, 1H, 7-H), 4.53 and 4.54 (each s, 1H, 4-H),
4.90 and 4.91 (each s, 2H, N—H), 5.93–5.94 (d, J = 3.24 Hz, 1H,
Furyl-H), 6.27–6.29 (t, J = 2.22 Hz, 1H, Furyl-H), 6.92–6.93 (d,
J = 4.80 Hz, 1H, Furyl-H), 7.10–7.35 (m, 4H, Ph-H). IR (KBr) n:
3345, 3223, 2149, 1605, 1551, 1435 cmꢁ1. MS (70 eV) m/z (%):
367.1 (M++1, 100). Anal. calcd for C20H15ClN2O3: C 65.49,
H 4.12, N 7.64; found C 65.57, H 4.19, N 7.70.
4p+5p 1H NMR (CDCl3, 300 MHz) d: 2.52–2.97 (m, 4H,
8-H+6-H), 3.35–3.51 and 3.52–3.70 (m, 4H, 7-H), 3.47 (s,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet