Synthesis of the first nano ionic liquid 1-methylimidazolium trinitromethanide {[HMIM]C(NO2)3} and its catalytic use for Hanztsch four-component condensation

Article abstract of DOI:10.1039/c4ra09117e

A novel, green and reusable nano ionic liquid and catalyst, namely 1-methylimidazolium trinitromethanide {[HMIM]C(NO₂)₃}, was designed and fully characterized by ¹H NMR, ¹³C NMR, IR, mass, X-ray diffraction patt

Full text of DOI:10.1039/c4ra09117e

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ARTICLE TYPE
Synthesis of the first nano ionic liquid 1-methylimidazolium
trinitromethanide {[HMIM]C(NO2)3} and its catalytic use for Hanztsch
four-component condensation
Mohammad Ali Zolfigol,*a Saeed Baghery,a Ahmad Reza Moosavi-Zare,*b Seyed Mohammad Vahdat,c
Heshmatollah Alinezhadd and Mohammad Norouzid
5
Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
that 1,4-DHP exhibit ions some medicinal applications
which contain cerebral anti chemic activity in the
treatment of Alzheimer’s disease,16 platelet anti
A novel, green and reusable nano ionic liquid and catalyst namely
1-Methyl imidazolium trinitromethanide {[HMIM]C(NO2)3} was
designed and fully characterized by 1H NMR, 13C NMR, IR, 10
mass, x-ray diffraction patterns (XRD) and Transmission electron
microscopy (TEM) analysis. The catalytic application of the
presented catalyst was successfully tested on the Hantzsch four-
component reaction of various aromatic aldehydes, 1,3-dione, β-
ketoester and ammonium acetate at room temperature under 15
solvent-free and mild conditions to give the polyhydroquinoline
derivatives in good to excellent yields. In the presented work,
some of products have been reported for the first time.
aggregators activity,17 neuro protectant18 and chemo 50
sensitizer acting in tumor therapy.19 Recently, these
compounds have been synthesized in the presence of
[pyridine‐SO3H]Cl,20 [Dsim]HSO4,21 TiO2 NPs,22 SnO2
NPs,23 [2-MPyH]OTf,24 Ni-nanoparticle,25 Baker's yeast,26
L-proline,27 [bmim]BF4,28 solvent-free conditions on 55
grinding,29 1-vinyl-3-ethylimidazolium iodide.30 Although
several catalysts for this transformation are known, newer
catalysts continue to attract attention for their difference
with the others, high novelty and effectiveness.
Introduction
In continuation to our studies involving the synthesis of 60
1,4-dihydropyridine,31-34 preparation and applications of
Ionic liquids (ILs) have received considerable attention in 20
the last decade, due to their specific properties1 and their
applications in chemistry2 including liquid-liquid
separations,3 nano materials synthesis,4 biocatalysis,5
polymerization reactions,6 extraction7 and dissolution
processes,8 catalysis9 and electrochemistry.10 Ionic liquids 25
mainly have low vapour pressure, non-volatility, high
polarity, solubility with certain organic solvents and/or
water and good solubility in organic and inorganic
materials.11
ionic liquids in organic synthesis,13,
we have
20, 35, 36
prepared
a
novel ionic liquid and catalyst namely
trinitromethanide
1-methylimidazolium
{[HMIM]C(NO2)3} and employed it for the preparation of 65
polyhydroquinoline derivatives under solvent-free reaction
conditions (Scheme 1 and 2).
Multi-component reactions (MCRs) play an important role 30
in combinatorial chemistry due of their capability to
preparation of target molecules with atomic economy and
high efficiency by the reaction of three or more starting
materials together in a single step. Furthermore, this
technique increases synthetic efficacy and simplicity of 35
the reaction with respect to the conventional organic
transformations.12, 13
Scheme 1. The synthesis of 1-methylimidazolium trinitromethanide as a nano
ionic liquid and catalyst.
R4
O
R2
O
O
1
OR3
2
O
O
Recently, much attention has been focused on the multi-
component synthesis of 1,4-dihydropyridine compounds
(1,4-DHP) because of their variation in biological 40
activities such as Ca2+ channel blockers.14 Furthermore,
they also have communal types of several bio active
compounds such as bronchodilators, hepatoprotective,
vasodilators, anti-tumor, anti-atherosclerotic and anti-
diabetic agents for the behavior of cardiovascular diseases 45
including hypertension.15 The recent investigations reveal
H
+
Nano ionic liquid catalyst (0.5 mol%)
Solvent-free, r.t.
R1
OR3
3
R4
O
R1
R1
NH4OAc
N
H
R5
N
H
R1
N
4
5, 6, 7
Me
C(NO2)3
1-Methylimidazolium trinitromethanide
R1= H or Me
R1= H or Me
2a: R2= COMe, R3= Me
2b: R2= COMe, R3= Et
2c: R2= CN, R3= Et
5: R3= Me, R5= Me
6: R3= Et, R5= Me
7: R3= Et, R5= NH2
Scheme 2. The synthesis of polyhydroquinoline derivatives catalyzed by 70
{[HMIM]C(NO2)3} as nano ionic liquid as a novel catalyst.
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Results and discussion
Characterization
of
1-methylimidazolium
trinitromethanide {[HMIM]C(NO2)3}
The structure of 1-methylimidazolium trinitromethanide as
a novel nano ionic liquid and catalyst was prepared and
identified by FT-IR, 1H NMR, 13C NMR, mass, TG, DTG,
XRD and TEM analysis.
5
The IR spectrum of the nano ionic liquid indicated an
abroad peak at 3144 cm−1 which can be related to N–H
stretching group on imidazolium ring. Additionally, the 10
two peaks observed at 1584 cm−1 and 1383 cm−1
correspond to vibrational modes of NO2 bonds (Fig. 1).
Fig. 3. The 13C NMR spectrum of the 1-methylimidazolium 25
trinitromethanide as an ionic liquid catalyst.
Thermal
gravimetric
analysis
(TGA)
of
1-methylimidazolium trinitromethanide as a novel nano
ionic liquid catalyst was also studied. The constant
illustrations are revealed in Fig. 4 and Fig. 5. The thermo 30
gravimetry (TG) and derivative thermo gravimetry (DTG)
illustrations of the ionic liquid catalyst exhibited weight
losses in one step, and decomposition after about 150 °C.
Fig. 1. The IR spectrum of 1-methylimidazolium trinitromethanide (a);
trinitromethane (b); 1-methylimidazole (c).
Furthermore, the 1H NMR and 13C NMR spectra of the 15
1-methylimidazolium trinitromethanide in DMSO-d6 are
displayed in Figures 2 and 3. As Figures 2 and 3, indicates
1
that, the important peak of H NMR spectra of nano ionic
liquid catalyst is linked to the acidic hydrogen (NH group
on imidazolium ring) which is observed in δ = 14.22 ppm. 20
Fig. 4. The thermogravimetry (TG) illustrations of nano ionic liquid catalyst.
Fig. 2. The 1H NMR spectrum of the novel nano ionic liquid as a catalyst.
Fig. 5. The derivative thermogravimetry (DTG) illustrations ofnano ionic 35
liquid catalyst.
2
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Size, shape and morphology of the nano ionic liquid
catalyst were investigated using X-ray diffraction (XRD)
pattern sand transmission electron microscopy (TEM)
imaging techniques. XRD patterns of the catalyst
{[HMIM]C(NO2)3} was studied in a domain of 10-90
degree (Figure 6). As shown at Figure 6, XRD patterns
exhibited diffraction lines of a high crystalline nature at 2θ
≈ 16.70◦, 19.70◦, 26.60◦, 29.70◦, 37.10◦ and 40.00◦. Peak
width (FWHM), size and inter planer distance studies of
reaction was achieved in the presence of 0.5 mol% of nano
ionic liquid catalyst at room temperature (Table 2, entry 40
3). No improvement in the reaction results was observed
by increasing the amount of the catalysts and the
temperature (Table 2, entries 4-11).
5
the catalyst could be worked out in the 16.70 to 40.00 10
degree and results have been summarized in Table 1. As
example, calculations for the highest diffraction line
19.70◦ confirmed that an FWHM of 0.22 a crystallite size
of the catalyst of ca. 36.67 nm via the Scherrer equation
[D =Kλ/(βcosθ)] and an inter planer distance of 0.450109 15
nm (sing the same highest diffraction line at 19.70◦) was
calculated to be via the Bragg equation: dhkl = λ/(2sinθ),
(λ : Cu radiation (0.154178 nm) were obtained. Most
importantly, crystallite sizes as obtained from the various
diffraction lines using the Scherrer equation were found to 20
be in the nanometer range (36.67-62.45 nm), which is
fundamentally in a good accordance with the transmission
electron microscopy (TEM) (Fig.7).
Fig. 7. Transmission electron microscopy (TEM) of the nano ionic liquid
catalyst.
45
Table 2. Effect of amount of the catalyst and temperature on the
condensation of between 2,5-dimethoxybenzaldehyde, dimedone, methyl
acetoacetate and ammonium acetate under solvent-free conditions.
Entry Catalyst amount (mol%) Temperature (oC) Time (min)
Yield (%)
1
2
—
0.2
0.5
0.5
0.5
0.5
0.5
1
25
25
60
30
7
—
53
97
97
97
87
81
97
97
95
95
3
25
4
50
7
5
75
7
6
100
125
25
10
15
7
7
8
9
2
25
7
Fig. 6. The XRD pattern of the nano ionic liquid catalyst.
10
11
5
25
10
10
Table 1. XRD data for the nano ionic liquid catalyst.
25
10
25
Peak width [FWHM]
(degree)
Size
[nm]
Inter planer distance
[nm]
Entry
2θ
To compare the efficiency of the solution versus solvent-
free conditions, a mixture of 2,5-dimethoxybenzaldehyde, 50
dimedone, methyl acetoacetate and ammonium acetate, as
model reaction, in the presence of 0.5 mol% of nano ionic
liquid catalyst in some various solvents such as C2H5OH,
H2O, CH2Cl2, CH3CN and CH3CO2Et was studied at room
temperature. The results are summarized in Table 3. As it 55
can be realized in Table 3, solvent-free condition was the
best conditions in this reaction.
1
17.60
0.18
44.68
0.503314
2
3
4
19.70
26.60
29.70
0.22
0.18
0.25
36.67
45.37
62.45
0.450109
0.334710
0.089457
5
6
37.10
40.00
0.21
0.19
39.51
44.68
0.242037
0.225132
Application of 1-methylimidazolium trinitromethanide as
an ionic liquid catalyst
After
the
synthesis
of
1-methylimidazolium
Table 3. The effect of various solvents on the reaction of between 2,5-
dimethoxybenzaldehyde, dimedone, methyl acetoacetate and ammonium
acetate catalyzed by 0.5 mol% of nano ionic liquid at room temperature. 60
trinitromethanide as a novel nano ionic liquid catalyst, to
optimize the reaction conditions, we have tested the 30
efficiency of the catalyst in the synthesis of
polyhydroquinoline derivatives (Scheme 1). For this
Entry
Solvent
Time (min)
Yield (%)
1
2
3
4
5
6
—
7
97
95
95
92
87
82
purpose, as
a
model, the condensation reaction of
dimedone, methyl
H2O
10
12
20
33
45
2,5-dimethoxybenzaldehyde,
C2H5OH
CH3CN
CH2Cl2
CH3CO2Et
acetoacetate and ammonium acetate was investigated 35
using different amounts of the catalyst at range of 25–125
°C under solvent-free conditions (Table 2). As Table 2,
indicates that, the best results were obtained when the
Stimulated by the significant results, and in order to
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confirmation of generalization and scope of this new
procedure, various polyhydroquinoline derivatives were
H2O. It should be mentioned that in the mentioned steps, 35
{[HMIM]C(NO2)3} gives a proton for the activation of
carbonyl groups and then the proton is transferred to the
catalyst in another steps. The mechanism is confirmed by
the literature.20, 21
synthesized
from
the
Hantzsch
four-component
condensation reaction of different aromatic aldehydes,
1,3-dione, β-ketoester and ammonium acetate in the
presence of a catalytic amount of 1-methylimidazolium
trinitromethanide {[HMIM]C(NO2)3} as a nano ionic
liquid catalyst under solvent-free reaction conditions. The
results have been depicted in Table 4. All aromatic
5
40
aldehydes including benzaldehyde and aldehydes 10
containing electron-releasing substituents, electron-
withdrawing substituents and halogens on their aromatic
ring afforded the analogous products in high to excellent
yields in short reaction times. The reaction times of
aromatic aldehydes having electron withdrawing groups 15
were rather faster than electron donating groups. However
meta- and para- substituted aromatic aldehydes offered
excellent results, ortho-substituted aromatic aldehydes
provided slightly lower yields due to the steric effects.
Table 4. Synthesis of polyhydroquinoline derivatives using 20
1-methylimidazolium trinitromethanide.
45
50
55
Entry
Aldehyde
R1 Time (min) Yield (%) M.p (oC)Ref.
5a 2,5-Dimethoxybenzaldehyde
H
H
10
20
96
94
238-240
224-22630
5b
5c
4-Hydroxy-3-
methoxybenzaldeyhe
4-N,N-
H
15
95
253-255
60
Dimethylaminobenzaldehyde
Biphenyl-4-carbaldehyde
Terephthaldehyde
Scheme 3. The suggested mechanism for the synthesis of
5d
5e
Me
Me
5
98
92
97
91
95
256-258
343-345
193-195
193-195
273-275
18
7
polyhydroquinoline
in
the
presence
of
1-methylimidazolium
5f 2,5-Dimethoxybenzaldehyde Me
trinitromethanide as a nano ionic liquid and catalyst.
5g
5h
α-Methylcinnamaldehyde
4-Hydroxy-3-
Me
Me
23
15
Additionally, recyclability of the catalyst was tested upon
the condensation of between 2,5-dimethoxybenzaldehyde, 65
dimedone, methyl acetoacetate and ammonium acetate. At
the end of the reaction, ethyl acetate was added to the
reaction mixture and heated to extract product and
remained starting materials. This solution was washed
with water to separate catalyst from the other materials 70
(the product is soluble in hot ethyl acetate and nano ionic
liquid catalyst is soluble in water). The aqueous layer was
decanted, separated and used for alternative reaction after
removing of water. We have been observed that the
catalytic activity of the catalyst was restored within the 75
limits of the experimental errors for six continuous runs
(Fig. 8).
methoxybenzaldeyhe
4-N,N-
5i
Me
12
95
228-23029
Dimethylaminobenzaldehyde
6a 2,5-Dimethoxybenzaldehyde
H
13
8
95
98
92
96
90
98
93
197-199
196-198
367-36920
191-193
218-220
247-249
211-213
6b
6c
Biphenyl-4-carbaldehyde
Terephthaldehyde
Me
Me
25
9
6d 2,5-Dimethoxybenzaldehyde Me
6e
7a
7b
α-Methylcinnamaldehyde
2,4-Dinirobenzaldehyde
4-Hydroxy-3-
Me
H
27
10
25
H
methoxybenzaldeyhe
4-N,N-
7c
H
18
93
259-261
Dimethylaminobenzaldehyde
Biphenyl-4-carbaldehyde
Terephthaldehyde
7d
7e
Me
Me
11
31
12
33
18
97
91
96
90
94
191-193
248-250
182-184
127-129
281-283
7f 2,5-Dimethoxybenzaldehyde Me
7g
7h
α-Methylcinnamaldehyde
4-Hydroxy-3-
Me
Me
methoxybenzaldeyhe
80
In a proposed mechanism (Scheme 3), we suggest that at
first dimedone is converted to its enol form using
{[HMIM]C(NO2)3} and reacted to activated aldehyde (by 25
{[HMIM]C(NO2)3} to give intermediate I. On the other
hand, the activated β-ketoester (by the catalyst) and
ammonia (resulted from ammonium acetate) affords
enamine II. Afterward, the intermediate I and enamine II
react with each other to give intermediate III. III is 30
converted to IV by tautomerization, and intermediate IV
affords V by intramolecular nucleophilic attack of the NH2
group to the activated carbonyl group. Finally,
polyhydroquinonine forms by removing one molecule
85
90
Fig. 8. Reusability of the nano ionic liquid catalyst in 7 minutes.
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water). The aqueous layer was decanted and catalyst 60
separated after removing of water. The remained catalyst
was used for alternative reaction. The solvent of organic
layer was evaporated and the crude product was purified
by recrystallization from ethanol (95%). In this study,
nano ionic liquid catalyst was recycled and reused for six 65
times without significant loss of its catalytic activity.
Spectral data:
1
The reused catalyst was also characterized by H NMR and
13C NMR spectra after its application in the reaction. These
spectra were same as those of the fresh catalyst (Fig. S4 and
S5). Also the size of the catalyst was studied after the
recovery process by transmission electron microscopy (TEM)
analysis. This study was showed that the catalyst was
recovered in Nano size. The related pictures were added in
Figure S6.
5
10
Methyl
4-(2,5-dimethoxyphenyl)-2-methyl-5-oxo-
(5a):
Conclusions
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
o
In this work, a novel, green and reusable catalyst namely
1-Methyl imidazolium trinitromethanide {[HMIM]C(NO2)3}
was designed and fully characterized by 1H NMR, 13C NMR,
IR, mass, x-ray diffraction patterns (XRD) and Transmission 15
electron microscopy (TEM) analysis. Catalytic application of
Yellow solid; M.p: 238-240 C; Yield: 96% (0.343 g); IR 70
(KBr): υ 3434, 3287, 3211, 3074, 2991, 1692 cm-1; 1H
NMR (400 MHz, DMSO-d6): δ 1.88-2.18 (m, 6H, —CH2),
2.48 (s, 3H, —CH3), 3.51 (s, 3H, —CH3), 3.63 (s, 3H, —
CH3), 3.66 (s, 3H, —CH3), 5.04 (s, 1H, —CH), 6.56 (d,
1H, J = 3.2 Hz, ArH), 6.65 (d, 1H, J = 3.2 Hz, ArH), 6.79 75
(s, 1H, ArH), 9.05 (s, 1H, —NH); 13C NMR (100 MHz,
DMSO-d6): δ 18.2, 21.4, 26.7, 32.6, 37.3, 50.9, 55.5, 56.8,
103.8, 110.0, 111.1, 113.1, 116.5, 137.0, 143.8, 152.0,
152.5, 153.3, 168.3, 194.7; MS: m/z = 357 [M]+.
{[HMIM]C(NO2)3} was studied on the
synthesis of
polyhydroquinoline derivatives by the four-component
reaction of various aromatic aldehydes, 1,3-dione, β-ketoester
and ammonium acetate at room temperature under solvent- 20
free and mild conditions. Additional investigations showed
that the nano ionic liquids acidity plays a key role in the acid-
catalyzed reactions. Some important advantages of this work
are low cost, cleaner reaction profile, relatively short reaction
time, high yield, ease of product isolation, recyclability of the 25
catalyst and compliance with the green chemistry protocols.
Methyl
4-(4-hydroxy-3-methoxyphenyl)-2-methyl-5-oxo- 80
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (5b): White
o
solid; M.p: 224-226 C; Yield: 94% (0.323 g); IR (KBr): υ
1
3394, 3313, 3228, 3076, 2951, 1682 cm-1; H NMR (400
MHz, DMSO-d6): δ 2.08-2.16 (m, 1H, —CH2), 2.20 (t,
2H, J = 8.0 Hz, —CH2), 2.26 (s, 3H, —CH3), 2.33-2.40 85
(m, 1H, —CH2), 2.47 (t, 2H, J = 8.4 Hz, —CH2), 3.55 (s,
3H, —CH3), 3.68 (s, 3H, —CH3), 4.81 (s, 1H, —CH),
6.48 (d, 1H, J = 2.0 Hz, ArH), 6.59 (s, 1H, ArH), 6.70 (d,
1H, J = 2.0 Hz, ArH), 8.63 (s, 1H, —OH), 9.10 (s, 1H, —
NH); 13C NMR (100 MHz, DMSO-d6): δ 18.7, 21.3, 26.6, 90
35.0, 37.2, 51.1, 55.9, 111.7, 112.2, 115.5, 119.6, 139.3,
144.5, 145.0, 145.1, 147.3, 151.6, 168.0, 195.2; MS: m/z =
343 [M]+.
Experimental
General procedure for the preparation of nano ionic liquid
catalyst: 1-methylimidazolium trinitromethanide
To
a round-bottomed flask (100 mL) containing 1- 30
methylimidazole (3 mmol; 0.246 g) in CH3CN (10 mL),
was added trinitromethane (3.1 mmol; 0.468 g) drop wise
o
and heated over a period of 120 min at 80 C. Afterward
the solvent was removed by distillation under reduced
o
pressure, the product was dried under vacuum at 80 C for 35
Methyl
4-(4-(dimethylamino)phenyl)-2-methyl-5-oxo-
(5c): 95
3 h. A yellow solid was formed (Scheme 2) quantitatively.
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
1-Methylimidazolium
trinitromethanide
o
o
Yellow solid; M.p: 253-255 C; Yield: 95% (0.322 g); IR
(KBr): υ 3283, 3213, 3074, 2949, 1696 cm-1; 1H NMR
(400 MHz, DMSO-d6): δ 1.73-1.80 (m, 2H, —CH2), 1.89
(t, 2H, J = 8.8 Hz, —CH2), 2.20 (t, 2H, J = 5.0 Hz, —
CH2), 2.27 (s, 3H, —CH3), 2.44 (s, 3H, —CH3), 2.78 (s, 100
3H, —CH3), 2.80 (s, 3H, —CH3), 4.78 (s, 1H, —CH),
6.56 (d, 2H, J = 8.4 Hz, ArH), 6.95 (d, 2H, J = 8.8 Hz,
ArH), 9.37 (s, 1H, —NH); 13C NMR (100 MHz, DMSO-
d6): δ 18.7, 21.3, 26.6, 26.8, 31.3, 34.6, 37.2, 37.3, 128.2,
128.4, 136.3, 136.5, 145.0, 149.0, 149.2, 151.2, 151.3, 105
168.1, 195.2, 195.3; MS: m/z = 340 [M]+.
{[HMIM]C(NO2)3}: M.p: 54-56 C; Yield: 97% (0.679 g);
Spectral data: IR (KBr): υ 3433, 3144, 1584, 1383 cm-1;
1H NMR (400 MHz, DMSO-d6): δ 3.87 (s, 3H, —CH3), 40
7.68 (d, 1H, J = 3.2 Hz, —CH); 7.71 (d, 1H, J = 3.2 Hz,
—CH), 9.08 (s, 1H, —CH), 14.23 (brs, 1H, —NH); 13C
NMR (100 MHz, DMSO-d6): δ 35.8, 46.5, 120.2, 123.6,
136.3; MS: m/z = 233 [M]+, 234 [M+H]+.
General procedure for the synthesis of polyhydroquinoline 45
derivatives
To a mixture of 1,3-dione (1mmol), aromatic aldehyde
(1mmol), β-ketoester (1mmol) and ammonium acetate
(1mmol) in a test tube, was added 1-methylimidazolium
trinitromethanide as a novel nano ionic liquid catalyst (0.5 50
mol%), and the resulting mixture was firstly stirred
magnetically under solvent-free conditions at room
temperature. After completion of the reaction, as
monitired by TLC (n-hexane/ethyl acetate: 4/1) ethyl
acetate (10 mL) was added to reaction mixture, stirred and 55
refluxed for 3 min, and then was washed with water (10
mL) and decanted to separate catalyst from the other
materials (the reaction mixture was soluble in hot ethyl
acetate and nano ionic liquid catalyst was soluble in
Methyl
4-(biphenyl-4-yl)-2,7,7-trimethyl-5-oxo-
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (5d): White
o
solid; M.p: 256-258 C; Yield: 98% (0.392 g); IR (KBr): υ
1
3289, 3219, 3077, 2958, 1703 cm-1; H NMR (400 MHz, 110
DMSO-d6): δ 0.87 (s, 3H, —CH3), 1.01 (s, 3H, —CH3),
2.03 (d, 1H, J = 8.2 Hz, —CH2), 2.21 (d, 1H, J = 8.0 Hz,
—CH2), 2.30 (s, 3H, —CH3), 2.33 (d, 1H, J = 5.0 Hz, —
CH2), 2.46 (d, 1H, J = 8.6 Hz, —CH2), 3.55 (s, 3H, —
CH3), 4.91 (s, 1H, —CH), 7.23 (d, 2H, J = 8.0 Hz, ArH), 115
7.33 (t, 1H, J = 7.4 Hz, ArH), 7.42 (d, 2H, J = 7.6 Hz,
ArH), 7.50 (d, 2H, J = 8.0 Hz, ArH), 7.60 (d, 2H, J = 7.6
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DOI: 10.1039/C4RA09117E
Hz, ArH), 9.14 (s, 1H, —NH); 13C NMR (100 MHz,
DMSO-d6): δ 18.8, 27.1, 29.5, 32.7, 35.8, 50.7, 51.2,
103.5, 110.3, 126.7, 126.9, 127.5, 128.3, 129.3, 138.1,
140.6, 145.9, 147.2, 150.1, 167.8, 194.8; MS: m/z = 401
[M]+.
6.50 (d, 1H, J = 2.0 Hz, ArH), 6.58 (s, 1H, ArH), 6.70 (d,
1H, J = 1.6 Hz, ArH), 8.63 (s, 1H, —OH), 9.03 (s, 1H, — 60
NH); 13C NMR (100 MHz, DMSO-d6): δ 18.7, 26.8, 32.6,
35.2, 51.1, 55.9, 112.2, 115.4, 119.7, 127.3, 129.0, 139.3,
145.0, 145.2, 145.9, 147.3, 149.7, 168.0, 184.7, 194.9;
MS: m/z = 371 [M]+.
5
Dimethyl
4,4'-(1,4-phenylene)bis(2,7,7-trimethyl-5-oxo-
(5e):
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate)
Methyl
4-(4-(dimethylamino)phenyl)-2,7,7-trimethyl-5- 65
(5i):
o
Yellow solid; M.p: 343-345 C; Yield: 92% (0.526 g); IR
(KBr): υ 3431, 3284, 3212, 3085, 2956, 1704 cm-1; 1H
oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
o
Yellow solid; M.p: 228-230 C; Yield: 95% (0.349 g); IR
(KBr): υ 3280, 3202, 3072, 2961, 1699 cm-1; 1H NMR
(400 MHz, DMSO-d6): δ 0.86 (s, 3H, —CH3), 1.00 (s, 3H,
—CH3), 1.99 (d, 1H, J = 8.8 Hz, —CH2), 2.18 (d, 1H, J = 70
8.0 Hz, —CH2), 2.26 (s, 3H, —CH3), 2.28 (d, 1H, J = 5.0
Hz, —CH2), 2.42 (d, 1H, J = 8.4 Hz, —CH2), 2.80 (s, 6H,
—CH3), 3.52 (s, 3H, —CH3), 4.73 (s, 1H, —CH), 6.55 (d,
2H, J = 8.8 Hz, ArH), 6.95 (d, 2H, J = 8.8 Hz, ArH), 9.00
(s, 1H, —NH); 13C NMR (100 MHz, DMSO-d6): δ 18.7, 75
27.0, 29.6, 32.6, 35.4, 50.8, 51.1, 110.7, 112.6, 121.4,
128.2, 137.0, 145.1, 149.6, 195.1; MS: m/z = 368 [M]+.
Ethyl 4-(2,5-dimethoxyphenyl)-2-methyl-5-oxo-1,4,5,6,7,8-
hexahydroquinoline-3-carboxylate (6a): Yellow solid;
NMR (400 MHz, DMSO-d6): δ 0.78 (s, 3H, —CH3), 0.82 10
(s, 3H, —CH3), 0.98 (s, 6H, —CH3), 1.09 (d, 1H, J = 7.2
Hz, —CH2), 1.91 (s, 1H, —CH2), 2.02 (d, 1H, J = 5.6 Hz,
—CH2), 2.11 (d, 1H, J = 9.0 Hz, —CH2), 2.17 (d, 1H, J =
8.8 Hz, —CH2), 2.24 (d, 1H, J = 2.4 Hz, —CH2), 2.26 (s,
6H, —CH3), 2.29 (d, 1H, J = 4.0 Hz, —CH2), 2.35 (d, 1H, 15
J = 3.2 Hz, —CH2), 3.50 (s, 3H, —CH3), 3.53 (s, 3H, —
CH3), 4.78 (s, 1H, —CH), 4.82 (s, 1H, —CH), 6.93 (d,
4H, J = 0.4 Hz, ArH), 9.07 (s, 2H, —NH); 13C NMR (100
MHz, DMSO-d6): δ 26.8, 27.2, 29.3, 29.5, 31.6, 32.7,
35.1, 35.3, 127.0, 127.1, 145.1, 145.2, 145.7, 148.8, 149.9, 20
150.1, 167.9, 194.8, 194.9; MS: m/z = 572 [M]+.
o
Methyl
4-(2,5-dimethoxyphenyl)-2,7,7-trimethyl-5-oxo-
(5f):
M.p: 197-199 C; Yield: 95% (0.352 g); IR (KBr): υ 3285, 80
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
3203, 3073, 2941, 1689 cm-1; 1H NMR (400 MHz, DMSO-
d6): δ 1.14 (t, 3H, J = 7.0 Hz, —CH3), 1.75 (t, 2H, J = 5.2
Hz, —CH2), 1.91 (q, 2H, J = 6.6 Hz, —CH2), 2.16 (s, 3H,
—CH3), 2.48 (t, 2H, J = 9.2 Hz, —CH2), 3.63 (s, 3H, —
CH3), 3.65 (s, 3H, —CH3), 3.98 (m, 2H, —CH2), 5.02 (s, 85
1H, —CH), 6.62 (d, 1H, J = 3.2 Hz, ArH), 6.65 (d, 1H, J =
3.2 Hz, ArH), 6.76 (s, 1H, ArH), 9.03 (s, 1H, —NH); 13C
NMR (100 MHz, DMSO-d6): δ 14.6, 18.3, 21.4, 26.7,
33.1, 37.3, 55.5, 56.7, 59.3, 103.7, 110.1, 111.1, 113.1,
117.0, 137.0, 144.0, 152.1, 152.4, 153.2, 167.8, 194.7; 90
MS: m/z = 371 [M]+.
o
Yellow solid; M.p: 193-195 C; Yield: 97% (0.373 g); IR
(KBr): υ 3278, 3241, 3208, 3077, 2946, 1701 cm-1; 1H 25
NMR (400 MHz, DMSO-d6): δ 0.87 (s, 3H, —CH3), 1.00
(s, 3H, —CH3), 1.94 (d, 1H, J = 8.0 Hz, —CH2), 2.15 (d,
1H, J = 8.0 Hz, —CH2), 2.17 (s, 3H, —CH3), 2.30 (d, 1H,
J = 8.4 Hz, —CH2), 2.43 (d, 1H, J = 8.4 Hz, —CH2), 3.50
(s, 3H, —CH3), 3.62 (s, 3H, —CH3), 3.65 (s, 3H, —CH3), 30
5.01 (s, 1H, —CH), 6.62 (s, 1H, ArH), 6.64 (d, 2H, J = 3.2
Hz, ArH), 6.78 (d, 2H, J = 2.0 Hz, ArH), 8.99 (s, 1H, —
NH); 13C NMR (100 MHz, DMSO-d6): δ 18.5, 26.7, 29.8,
32.5, 33.1, 40.0, 50.8, 50.9, 55.5, 56.5, 103.4, 109.0,
111.3, 112.6, 116.9, 136.7, 144.4, 150.6, 151.9, 153.1, 35
168.2, 198.3; MS: m/z = 385 [M]+.
Ethyl 4-(biphenyl-4-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-
hexahydroquinoline-3-carboxylate (6b): White solid; M.p:
196-198 oC; Yield: 98% (0.406 g); IR (KBr): υ 3306,
1
Methyl 2,7,7-trimethyl-5-oxo-4-(1-phenylprop-1-en-2-yl)-
3080, 2956, 1690 cm-1; H NMR (400 MHz, DMSO-d6): δ 95
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
(5g):
0.87 (s, 3H, —CH3), 1.02 (s, 3H, —CH3), 1.17 (t, 3H, J =
7.0 Hz, —CH3), 2.02 (d, 1H, J = 8.8 Hz, —CH2), 2.20 (d,
1H, J = 8.2 Hz, —CH2), 2.30 (s, 3H, —CH3), 2.34 (d, 1H,
J = 7.6 Hz, —CH2), 2.46 (d, 1H, J = 8.6 Hz, —CH2), 4.02
(q, 2H, J = 7.2 Hz, —CH2), 4.90 (s, 1H, —CH), 7.25 (d, 100
2H, J = 8.4 Hz, ArH), 7.34 (t, 1H, J = 7.8 Hz, ArH), 7.42
(d, 2H, J = 8.0 Hz, ArH), 7.50 (d, 2H, J = 8.4 Hz, ArH),
7.61 (d, 2H, J = 9.2 Hz, ArH), 9.10 (s, 1H, —NH); 13C
NMR (100 MHz, DMSO-d6): δ 14.6, 18.8, 27.1, 29.5,
32.7, 36.0, 50.7, 59.6, 103.9, 110.3, 126.6, 126.9, 127.5, 105
128.5, 129.3, 138.1, 140.1, 145.5, 147.3, 150.1, 167.3,
194.8; MS: m/z = 415 [M]+.
o
Yellow solid; M.p: 193-195 C; Yield: 91% (0.332 g); IR
(KBr): υ 3424, 3284, 3213, 3081, 2956, 1704 cm-1; 1H 40
NMR (400 MHz, DMSO-d6): δ 1.00 (s, 6H, —CH3), 1.03
(s, 3H, —CH3), 1.76 (d, 4H, J = 1.2 Hz, —CH2), 2.27 (s,
3H, —CH3), 3.61 (s, 3H, —CH3), 4.45 (s, 1H, —CH),
6.19 (s, 1H, —CH), 7.13 (d, 2H, J = 7.2 Hz, ArH), 7.17 (t,
1H, J = 7.2 Hz, ArH), 7.29 (d, 2H, J = 7.6 Hz, ArH), 9.00 45
(s, 1H, —NH); 13C NMR (100 MHz, DMSO-d6): δ 16.3,
18.6, 26.8, 26.9, 29.7, 32.4, 32.5, 50.9, 51.1, 102.5, 108.7,
125.1, 126.3, 128.6, 128.9, 129.1, 138.4, 143.0, 145.9,
150.5, 168.1, 195.0; MS: m/z = 365 [M]+.
Methyl 4-(4-hydroxy-3-methoxyphenyl)-2,7,7-trimethyl-5- 50
Diethyl
4,4'-(1,4-phenylene)bis(2,7,7-trimethyl-5-oxo-
oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
(5h):
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate)
(6c):
White solid; M.p: 273-275 oC; Yield: 95% (0.352 g); IR
(KBr): υ 3372, 3292, 3243, 3069, 2956, 1702 cm-1; 1H
NMR (400 MHz, DMSO-d6): δ 0.88 (s, 3H, —CH3), 1.01
(s, 3H, —CH3), 2.01 (d, 1H, J = 7.8 Hz, —CH2), 2.20 (d, 55
1H, J = 8.0 Hz, —CH2), 2.26 (s, 3H, —CH3), 2.30 (d, 1H,
J = 6.4 Hz, —CH2), 2.44 (d, 1H, J = 8.4 Hz, —CH2), 3.55
(s, 3H, —CH3), 3.66 (s, 3H, —CH3), 4.76 (s, 1H, —CH),
White solid; M.p: 367-369 oC; Yield: 92% (0.552 g); IR 110
(KBr): υ 3453, 3283, 3221, 3087, 2960, 1702 cm-1; 1H
NMR (400 MHz, DMSO-d6): δ 0.98 (s, 6H, —CH3), 1.02
(s, 6H, —CH3), 1.04 (s, 6H, —CH3), 1.11 (t, 6H, J = 7.0
Hz, —CH3), 1.96 (d, 2H, J = 8.0 Hz, —CH2), 2.15 (d, 2H,
J = 8.2 Hz, —CH2), 2.27 (d, 2H, J = 8.0 Hz, —CH2), 2.41 115
(d, 2H, J = 8.4 Hz, —CH2), 3.98 (q, 4H, J = 9.6 Hz, —
6
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CH2), 4.73 (s, 2H, —CH), 6.76 (s, 2H, ArH), 6.94 (s, 2H,
ArH), 9.00 (s, 2H, —NH); 13C NMR (100 MHz, DMSO-
d6): δ 14.8, 15.5, 16.4, 18.5, 21.3, 22.0, 26.8, 26.9, 28.4,
128.1, 128.2, 128.4, 128.5, 129.1, 138.4, 152.1, 152.6,
167.6, 195.3, 195.5; MS: m/z = 600 [M]+.
ArH), 6.74 (s, 1H, —OH), 6.79 (d, 1H, J = 1.6 Hz, ArH),
8.52 (s, 1H, —NH); 13C NMR (100 MHz, DMSO-d6): δ
21.0, 29.1, 32.1, 35.4, 55.4, 55.9, 60.6, 100.5, 101.4, 60
113.1, 115.0, 116.5, 121.0, 136.4, 144.5, 147.0, 167.4,
174.8, 195.9; MS: m/z = 358 [M]+.
5
Ethyl
4-(2,5-dimethoxyphenyl)-2,7,7-trimethyl-5-oxo-
Ethyl
2-amino-4-(4-(dimethylamino)phenyl)-5-oxo-
(7c):
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (6d): White
o
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
o
solid; M.p: 191-193 C; Yield: 96% (0.383 g); IR (KBr): υ
Yellow solid; M.p: 259-261 C; Yield: 93% (0.330 g); IR 65
(KBr): υ 3269, 3174, 3062, 2921, 1641 cm-1; 1H NMR
(400 MHz, DMSO-d6): δ 1.90 (m, 2H, —CH2), 2.20 (t,
3H, J = 5.2 Hz, —CH3), 2.35 (q, 2H, J = 6.6 Hz, —CH2),
2.44 (t, 2H, J = 6.8 Hz, —CH2), 2.48 (t, 2H, J = 8.0 Hz, —
CH2), 2.72 (s, 3H, —CH3), 2.89 (s, 3H, —CH3), 4.78 (s, 70
1H, —CH), 6.54 (d, 1H, J = 8.8 Hz, ArH), 6.60 (d, 1H, J =
8.8 Hz, ArH), 6.87 (d, 1H, J = 8.4 Hz, ArH), 6.95 (d, 1H,
J = 8.8 Hz, ArH), 7.72 (s, 2H, —NH2), 9.34 (s, 1H, —
NH); 13C NMR (100 MHz, DMSO-d6): δ 20.8, 21.3, 26.8,
29.8, 31.0, 31.3, 35.9, 37.3, 112.2, 112.7, 112.9, 113.4, 75
127.3, 128.4, 136.3, 148.6, 149.0, 151.2, 195.2; MS: m/z =
355 [M]+.
3307, 3231, 3099, 2959, 1691 cm-1; H NMR (400 MHz,
1
DMSO-d6): δ 0.86 (s, 3H, —CH3), 1.00 (s, 3H, —CH3), 10
1.14 (t, 3H, J = 7.2 Hz, —CH3), 1.93 (d, 1H, J = 8.0 Hz,
—CH2), 2.14 (d, 1H, J = 8.2 Hz, —CH2), 2.18 (s, 3H, —
CH3), 2.26 (d, 1H, J = 8.6 Hz, —CH2), 2.42 (d, 1H, J =
8.6 Hz, —CH2), 3.63 (s, 3H, —CH3), 3.64 (s, 3H, —CH3),
3.94 (q, 2H, J = 5.4 Hz, —CH2), 4.99 (s, 1H, —CH), 6.62 15
(d, 1H, J = 3.2 Hz, ArH), 6.65 (d, 1H, J = 2.4 Hz, ArH),
6.77 (s, 1H, ArH), 8.97 (s, 1H, —NH); 13C NMR (100
MHz, DMSO-d6): δ 14.6, 18.5, 26.7, 29.8, 32.5, 33.5,
40.1, 50.8, 55.5, 56.3, 59.3, 103.3, 109.0, 111.3, 112.4,
117.3, 136.6, 144.5, 150.5, 152.0, 153.0, 167.7, 194.3; 20
MS: m/z = 399 [M]+.
Ethyl
2-amino-4-(biphenyl-4-yl)-7,7-dimethyl-5-oxo-
(7d):
Ethyl
2,7,7-trimethyl-5-oxo-4-(1-phenylprop-1-en-2-yl)-
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
o
Orange solid; M.p: 191-193 C; Yield: 97% (0.404 g); IR 80
(KBr): υ 3305, 3080, 3030 2955, 1690 cm-1; H NMR (400
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (6e): Yellow
solid; M.p: 218-220 oC; Yield: 90% (0.341 g); IR (KBr): υ
3281, 3211, 3080, 2956, 1699 cm-1; 1H NMR (400 MHz, 25
DMSO-d6): δ 1.00 (s, 3H, —CH3), 1.03 (s, 3H, —CH3), 1.22
(t, 3H, J = 7.2 Hz, —CH3), 1.76 (s, 3H, —CH3), 2.10 (d, 1H, J
= 8.0 Hz, —CH2), 2.22 (d, 1H, J = 8.2 Hz, —CH2), 2.27 (s,
3H, —CH3), 2.30 (d, 1H, J = 6.6 Hz, —CH2), 2.42 (d, 1H, J =
8.4 Hz, —CH2), 4.10 (q, 2H, J = 6.8 Hz, —CH2), 4.46 (s, 1H, 30
—CH), 6.21 (s, 1H, —CH), 7.13 (d, 2H, J = 7.4 Hz, ArH),
7.17 (t, 1H, J = 7.2 Hz, ArH), 7.29 (d, 2H, J = 7.6 Hz, ArH),
8.96 (s, 1H, —NH); 13C NMR (100 MHz, DMSO-d6): δ 14.8,
16.2, 18.6, 26.9, 29.7, 32.4, 50.9, 59.4, 102.7, 108.6, 125.3,
126.3, 128.6, 129.0, 138.4, 142.8, 145.6, 150.6, 167.6, 35
194.9; MS: m/z = 379 [M]+.
1
MHz, DMSO-d6): δ 0.88 (s, 3H, —CH3), 1.02 (s, 3H, —
CH3), 1.17 (t, 3H, J = 7.0 Hz, —CH3), 2.02 (d, 1H, J = 8.0
Hz, —CH2), 2.20 (d, 1H, J = 8.0 Hz, —CH2), 2.30 (s, 2H,
—NH2), 2.34 (d, 1H, J = 7.4 Hz, —CH2), 2.46 (d, 1H, J = 85
8.4 Hz, —CH2), 4.02 (q, 2H, J = 7.2 Hz, —CH2), 4.90 (s,
1H, —CH), 7.25 (d, 2H, J = 8.4 Hz, ArH), 7.33 (t, 1H, J =
6.0 Hz, ArH), 7.42 (d, 2H, J = 8.0 Hz, ArH), 7.50 (d, 2H,
J = 8.4 Hz, ArH), 7.61 (d, 2H, J = 8.4 Hz, ArH), 9.10 (s,
1H, —NH); 13C NMR (100 MHz, DMSO-d6): δ 14.6, 18.8, 90
27.1, 29.5, 32.7, 36.1, 50.7, 59.6, 103.9, 110.3, 126.6,
127.0, 127.5, 128.5, 129.3, 138.1, 140.6, 145.5, 147.4,
150.1, 167.3, 194.8; MS: m/z = 416 [M]+.
Diethyl 4,4'-(1,4-phenylene)bis(2-amino-7,7-dimethyl-5-
oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) (7e): 95
White solid; M.p: 248-250 oC; Yield: 91% (0.548 g); IR
(KBr): υ 3491, 3427, 3310, 2960, 1691 cm-1; 1H NMR
(400 MHz, DMSO-d6): δ 0.82 (s, 6H, —CH3), 1.01 (t, 6H,
J = 7.2 Hz, —CH3), 1.02 (s, 6H, —CH3), 2.03 (d, 2H, J =
8.0 Hz, —CH2), 2.27 (d, 2H, J = 8.0 Hz, —CH2), 2.43 (d, 100
2H, J = 8.6 Hz, —CH2), 2.57 (d, 2H, J = 8.6 Hz, —CH2),
3.93 (q, 4H, J = 8.2 Hz, —CH2), 4.40 (s, 2H, —CH), 6.94
(s, 4H, ArH), 7.51 (s, 4H, —NH2), 9.14 (s, 2H, —NH);
13C NMR (100 MHz, DMSO-d6): δ 14.5, 26.4, 29.3, 32.3
50.3, 59.1, 78.2, 97.4, 106.8, 115.9, 127.4, 132.8, 159.6, 105
162.4, 196.2; MS: m/z = 602 [M]+.
Ethyl
2-amino-4-(2,4-dinitrophenyl)-5-oxo-1,4,5,6,7,8-
hexahydroquinoline-3-carboxylate (7a): Brown solid;
o
M.p: 247-249 C; Yield: 98% (0.394 g); IR (KBr): υ 3311,
3267, 3197, 3108, 3007, 1620 cm-1; H NMR (400 MHz, 40
1
DMSO-d6): δ 1.93 (t, 6H, J = 5.8 Hz, —CH2), 2.17 (t, 3H,
J = 6.2 Hz, —CH3), 2.47 (q, 2H, J = 5.8 Hz, —CH2), 4.96
(s, 1H, —CH), 7.24 (d, 1H, J = 9.6 Hz, ArH), 8.35(d, 1H,
J = 6.0 Hz, ArH), 8.86 (s, 1H, ArH), 9.36 (s, 1H, —NH),
10.19 (s, 2H, —NH2); 13C NMR (100 MHz, DMSO-d6): δ 45
26.9, 28.2, 29.7, 31.7, 32.6, 35.5, 104.5, 112.4, 115.4,
139.5, 144.8, 145.0, 147.2, 149.7, 162.0, 162.8, 167.6,
194.8; MS: m/z = 402 [M]+.
Ethyl
2-amino-4-(2,5-dimethoxyphenyl)-7,7-dimethyl-5-
Ethyl
2-amino-4-(4-hydroxy-3-methoxyphenyl)-5-oxo-
oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate
(7f):
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (7b): White 50
o
White solid; M.p: 182-184 oC; Yield: 96% (0.384 g); IR
(KBr): υ 3424, 3314, 2956, 1689 cm-1; 1H NMR (400 110
MHz, DMSO-d6): δ 0.86 (s, 3H, —CH3), 1.03 (s, 3H, —
CH3), 1.10 (t, 3H, J = 7.0 Hz, —CH3), 2.00 (d, 1H, J = 8.0
Hz, —CH2), 2.26 (d, 1H, J = 8.0 Hz, —CH2), 2.36 (d, 1H,
J = 8.8 Hz, —CH2), 2.57 (d, 1H, J = 8.8 Hz, —CH2), 3.62
(s, 3H, —CH3), 3.67 (s, 3H, —CH3), 3.91 (q, 2H, J = 5.2 115
solid; M.p: 211-213 C; Yield: 93% (0.333 g); IR (KBr): υ
1
3423, 3279, 3201, 3069, 2946, 1696 cm-1; H NMR (400
MHz, DMSO-d6): δ 2.13 (t, 3H, J = 5.2 Hz, —CH3), 2.19
(d, 1H, J = 5.2 Hz, —CH2), 2.37 (q, 2H, J = 7.4 Hz, —
CH2), 2.44 (t, 4H, J = 6.2 Hz, —CH2), 2.96 (d, 1H, J = 5.4 55
Hz, —CH2), 3.69 (s, 3H, —CH3), 5.76 (s, 1H, —CH), 6.54
(s, 2H, —NH2), 6.70 (d, 1H, J = 2.0 Hz, ArH), 6.74 (s, 1H,
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DOI: 10.1039/C4RA09117E
Hz, —CH2), 4.49 (s, 1H, —CH), 6.67 (d, 1H, J = 3.2 Hz,
Przem Chem., 2003, 82, 521; (c) S.A. Forsyth, J.M. 60
Pringle and D.R. MacFarlane, Aust. J. Chem., 2004,
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ArH), 6.71 (d, 1H, J = 3.2 Hz, ArH), 6.77 (s, 1H, ArH),
7.48 (s, 2H, —NH2), 9.37 (s, 1H, —NH); 13C NMR (100
MHz, DMSO-d6): δ 14.7, 26.3, 29.4, 32.1, 32.2, 50.5,
55.6, 56.2, 59.0, 76.2, 111.6, 112.3, 113.5, 118.2, 133.8,
152.3, 152.6, 160.1, 163.0 168.8, 196.2; MS: m/z = 400
[M]+.
5
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-(1-phenylprop-1-en-
2
(a) P. Wasserscheid and W. Keim, (Eds.) "Ionic Liquids
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2-yl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (7g):
o
Yellow solid; M.p: 127-129 C; Yield: 90% (0.342 g); IR 10
(KBr): υ 3275, 3181, 3063, 2959, 1647 cm-1; 1H NMR
(400 MHz, DMSO-d6): δ 1.00 (s, 6H, —CH3), 1.04 (s, 3H,
—CH3), 1.10 (t, 3H, J = 5.6 Hz, —CH3), 2.11 (d, 2H, J =
7.8 Hz, —CH2), 2.23 (d, 2H, J = 7.8 Hz, —CH2), 2.33 (q,
2H, J = 8.6 Hz, —CH2), 2.57 (s, 1H, —CH), 2.47 (s, 2H, 15
—NH2), 6.17 (s, 1H, —CH), 7.08 (d, 2H, J = 7.6 Hz,
ArH), 7.16 (d, 2H, J = 7.2 Hz, ArH), 7.29 (d, 1H, J = 7.6
Hz, ArH), 9.19 (s, 1H, —NH); 13C NMR (100 MHz,
DMSO-d6): δ 18.1, 19.0, 26.8, 28.6, 29.7, 32.5, 36.8, 42.5,
50.9, 111.3, 119.6, 123.3, 125.5, 125.9, 126.3, 127.7, 20
128.1, 128.5, 128.9, 129.5, 138.5, 142.5, 144.9, 144.9,
195.2; MS: m/z = 380 [M]+.
3
4
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Ethyl
2-amino-4-(4-hydroxy-3-methoxyphenyl)-7,7-
dimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-
carboxylate (7h): Yellow solid; M.p: 281-283 oC; Yield: 25
5
(a) S.G. Cull, J.D. Holbrey, V. Vargas-Mora, K.R.
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94% (0.363 g); IR (KBr): υ 3414, 3274, 3194, 3070, 2962,
1
1687 cm-1; H NMR (400 MHz, DMSO-d6): δ 0.88 (s, 6H,
—CH3), 1.01 (t, 3H, J = 7.2 Hz, —CH3), 2.02 (d, 2H, J =
8.0 Hz, —CH2), 2.19 (q, 2H, J = 8.0 Hz, —CH2), 2.33 (d,
2H, J = 8.4 Hz, —CH2), 2.46 (s, 2H, —NH2), 3.65 (s, 3H, 30
—CH3), 4.71 (s, 1H, —CH), 6.52 (d, 1H, J = 1.6 Hz,
ArH), 6.53 (s, 1H, ArH), 6.70 (d, 1H, J = 2.0 Hz, ArH),
8.58 (s, 1H, —OH), 9.23 (s, 1H, —NH); 13C NMR (100
MHz, DMSO-d6): δ 26.8, 29.6, 32.3, 32.6, 50.8, 55.9,
78.7, 112.2, 112.6, 115.2, 120.2, 139.0, 144.8, 147.1, 35
149.4, 159.5, 194.9, 196.4; MS: m/z = 386 [M]+.
6
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Acknowledgements
The authors gratefully acknowledge the Bu-Ali Sina
University Research Council and Center of Excellence in
Development of Environmentally Friendly Methods for 40
Chemical Synthesis (CEDEFMCS) for providing support
to this work.
8
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Notes and references
aFaculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, 45
Iran
bDepartment of Chemistry, University of Sayyed Jamaleddin Asadabadi,
Asadabad 6541835583, Iran
cDepartment of Chemistry, Ayatollah Amoli Branch, Islamic Azad
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University, P.O. Box 678, Amol, Iran
dDepartment of Chemistry, Mazandaran University, Babolsar 47415, Iran
*Corresponding Author: Fax: +988138257407
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E-mail: zolfi@basu.ac.ir and mzolfigol@yahoo.com (M.A. Zolfigol);
moosavizare@yahoo.com (A.R. Moosavi-Zare).
† Electronic Supplementary Information (ESI) available: [details of any 55
supplementary information available should be included here]. See
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DOI: 10.1039/C4RA09117E
Graphical Abstract
2014, 25, 193.
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NO
C
2 H
O2N
O2N
N
N
Me
Nano ionic liquid catalyst (0.5 mol%)
Solvent-free, r.t.
R4
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5
O
R2
O
O
1
OR3
R4
O
O
2
H
OR3
+
R1
R1
R1
R1
R1= Hor Me
3
O
N
H
R5
NH4OAc
4
2a: R2= COMe, R3= Me
2b: R2= COMe, R3= Et
2c: R2= CN, R3=Et
5, 6, 7
R1= Hor Me
5: R3= Me, R5= Me
6: R3= Et, R5= Me
7: R3= Et, R5= NH2
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Synthesis of the first nano ionic liquid 1-methylimidazolium
trinitromethanide {[HMIM]C(NO2)3} and its catalytic use for 60
Hanztsch four-component condensation
Mohammad Ali Zolfigol,*a Saeed Baghery,a Ahmad Reza Moosavi-
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1-Methyl imidazolium trinitromethanide {[HMIM]C(NO2)3} as novel nano 65
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