An efficient and facile synthesis of novel substituted pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine

Article abstract of DOI:10.1007/s11164-012-0559-0

One-pot, multicomponent reaction for the synthesis of novel substituted pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine from aromatic aldehydes, 1-nitroguanidine, and malononitrile under ethanol is described. Because of containing ma

Full text of DOI:10.1007/s11164-012-0559-0

Res Chem Intermed (2012) 38:2435–2442
DOI 10.1007/s11164-012-0559-0
An efficient and facile synthesis of novel substituted
pyrimidine derivatives: 4-amino-5-carbonitrile-2-
nitroaminopyrimidine
•
Sheng Xia Shan Yin Shimin Tao Yanhui Shi
•
•
•
•
Liangce Rong Xianyong Wei Zhimin Zong
•
Received: 26 January 2012 / Accepted: 10 April 2012 / Published online: 3 May 2012
Ó Springer Science+Business Media B.V. 2012
Abstract One-pot, multicomponent reaction for the synthesis of novel substituted
pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine from aro-
matic aldehydes, 1-nitroguanidine, and malononitrile under ethanol is described.
Because of containing many active functional groups, such as amino, cyan and
nitro, these products are important intermediate of organic synthesis. The advan-
tages of this procedure include the short reaction time, mild reaction conditions, and
excellent yields.
Keywords 2-Nitroaminopyrimidine Á Heterocyclic compound Á 1-Nitroguanidine Á
Multicomponent reactions
Introduction
Pyrimidines and their derivatives, as an integral part of DNA and RNA in it, play an
important role in several biological processes and have considerable chemical and
pharmacological importance. Particularly, the pyrimidine ring can be found in
nucleoside antibiotics, antibacterial, cardiovascular, as well as agrochemical and
veteran products [1–6]. Recently, some new substituted pyrimidine derivatives have
been synthesized that exhibit analgesic, anti-inflammatory, anti-parkinsonian, and
androgenic–anabolic activities [7–9]. 4-Aminopyrimidine derivatives as the
S. Xia Á S. Yin Á S. Tao Á Y. Shi Á L. Rong (&)
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, College
of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou 221116, Jiangsu,
People’s Republic of China
e-mail: lcrong2005@yahoo.com
L. Rong Á X. Wei Á Z. Zong
School of Chemical Engineering and Technology, China University of Mining and Technology,
Xuzhou 221006, Jiangsu, People’s Republic of China
123

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S. Xia et al.
important component of pyrimidine are widely used in the field of medicine and
pesticides. They are the important intermediate for the synthesis of agrochemical
fungicides, herbicide, analgesics, anti-cancer drugs, and so on [10]. Therefore, it is
important and necessary to find an efficient method and facile procedure to
synthesize some 4-aminopyrimidine derivatives. Herein, we would like to report
some novel 4-aminopyrimidine derivatives by the reactions of 1-nitroguanidine,
aldehydes, and malononitrile.
Results and discussion
Under investigating literatures, we found that some guanidine and amidine, such as
guanidine hydrochloride [11] and guanidine carbonate [12], were efficient reagents
for the synthesis of 4-aminopyrimidine derivatives. However, the 1-nitroguanidine
was not used to prepare these compounds, so we wanted to synthesize 4-amino-
pyrimidine from 1-nitroguanidine.
In our study, ethanol (95 %), owing to its low toxicity, being easy to obtain, and
inexpensive cost, was chosen as the preferred solvent to implement this reaction. 4-
Fluorobenzaldehyde 1b, 1-nitroguanidine 2, and malononitrile 3 were chosen as
starting materials to optimize the reaction conditions. The reaction was carried out
in ethanol (95 %) under reflux condition in the absence and presence of several
catalysts. The results are summarized in Table 1. The results show that when proton
acid (Table 1, entries 2 and 3), weak base (Table 1, entries 4 and 5), or organic
bases (Table 1, entries 11 and 12) were used as catalysts, the reactions could not
occur or the yields of the product were very low. When strong-base NaOH was used
as a catalyst, the reaction could be carried out smoothly with a high yield. Another
strong-base KOH could also catalyze reaction, but the yield is not obviously
improved. So NaOH was chosen as the preferred catalyst for this reaction.
Using this optimized reaction condition (Table 1, entry 7), a series of 4-amino-5-
carbonitrile-2-nitroaminopyrimidine derivatives could be obtained with high yields
Table 1 Synthesis of 4b under
ethanol in the presence of
different catalysts
Entry
Additive
Time (h)
Amount (mmol)
Yieldsa (%)
1
None
1
2
2
2
2
2
2
1
1
1
1
2
2
0
0
2
HCl
1
3
H2SO4
Na2CO3
K2CO3
NaOH
NaOH
NaOH
NaOH
KOH
1
0
4
1
15
24
87
91
88
90
87
0
5
1
6
1
7
1
8
0.5
1.5
1
9
10
11
12
Piperidine
Et3N
1
a
Isolated yields, reflux
condition
1
0
123

An efficient and facile synthesis of novel substituted pyrimidine derivatives
2437
(Scheme 1). The results are listed in Table 2. As shown in Table 2, this protocol
could be operated not only with the aromatic aldehydes with electron-withdrawing
groups (such as halide groups) but also with the aromatic aldehydes with electron-
donating groups (such as methyl and alkoxyl groups) under the same conditions.
Recently, Ahmadi [13] reported to use CuO microspheres as a catalyst to synthesize
some 4-aminopyrimidine derivatives. However, it was very difficult to prepare
granulated copper oxide and all products (nine compounds) in this paper are old
compounds.
The corresponding products were obtained in 87–98 % yields. Structure of the
1
product 4 was confirmed by infrared (IR), H NMR, elemental analysis, and high-
resolution mass spectrometry (HRMS).
We take 4g as an example to analyze their structure. In 4g 1H NMR, its spectrum
revealed singlet signal at d = 2.39 (3H) ppm due to CH3 protons. The doublet
signal at d = 7.37 (2H) and doublet signals at 7.59 (2H) ppm due to four phenyl
protons, in addition to a singlet signal at 7.97 ppm and a broad singlet signal at
R
CHO
NH
NHNO2
CN
NaOH
NC
+
+
N
R
H2N
CN
H2N
N
NHNO2
3
4
1
2
Scheme 1 Synthesis of 4-amino-5-carbonitrile-2-nitroaminopyrimidine
Table 2 Synthetic results of
compounds 4
Entry Ar
Products Times (h) Yields (%)
1
C6H5
4a
4b
4c
4d
4e
4f
1
88
91
90
89
90
92
90
86
89
87
91
94
89
92
85
2
4-FC6H4
1
3
4-ClC6H4
1
4
2,4-Cl2C6H3
3,4-Cl2C6H3
4-BrC6H4
0.5
0.5
1
5
6
7
4-CH3C6H4
4g
4h
4i
1
8
3,4-(CH3)2C6H3
2-CH3OC6H4
4-CH3OC6H4
2,5-(CH3O)2C6H3
3,4-(CH3O)2C6H3
1
9
0.5
0.5
1
10
11
12
13
14
15
4j
4k
4l
0.5
1
3,4,5-(CH3O)3C6H2 4m
3,4-OCH2OC6H3
1-naphthalene
4n
4o
0.5
1
123

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S. Xia et al.
11.79 due to the NH2 and NH protons. In the HRMS spectrum, the calculated m/z
(C12H10N6O2 [M]?)of 4g is 270.0865, and the found m/z is 270.0828.
Conclusions
In conclusion, we have reported an efficient and convenient method for the
synthesis of 4-amino-5-carbonitrile-2-nitroaminopyrimidine derivatives by the
three-component reaction of aromatic aldehydes, 1-nitroguanidine and malononit-
rile. The crude product can be recrystallized after washing with water or dilute HCl
to neutral in ethanol. This process also offers many other attractive features such as
lower cost, high yields, reduced reaction times, and economic viability of the
catalyst. Because of containing many active functional groups, such as amino, cyan,
and nitro, these products are important intermediate of organic synthesis. In
addition, 15 products in the text are firstly reported.
Experimental
Melting points were determined on an XT-5 microscopic melting point spectrometer
and are uncorrected. IR spectra were recorded on a Fourier transform FT-IR-8101
1
spectrometer. H NMR spectra were obtained from solution in dimethyl sulfoxide
(DMSO-d6) with Me4Si as internal standard using a Bruker-400 spectrometer.
Microanalyses were carried out using a Perkin-Elmer 2400 II analyzer. HRMS
spectra were obtained with a Bruker microTOF-Q 134 instrument.
General procedure for the synthesis of Compound 4
A mixture of aromatic aldehyde 1 (2 mmol), 1-nitroguanidine 2 (2 mmol),
malononitrile 3 (2 mmol), NaOH (1 mmol), and 10 mL EtOH (95 %) was added
in a round flask. The reaction mixture was stirred under reflux conditions for
0.5–1 h. After completion of the reaction (monitored by TLC), the reactants were
poured into water and then washed with water. The products were filtered, dried,
and recrystallized from 95 % ethanol.
4-Amino-5-carbonitrile-2-nitroamino-6-phenylpyrimidine (4a)
Melting point[290 °C; IR (KBr, m, cm-1): 3,343, 3,115, 2,733, 2,216, 1,652, 1,604,
1,571, 1,477, 1,438, 1,269, 1,232, 1,159, 1,132, 932, 778, 764, 698, 679, 617 cm-1
;
1H NMR (400 MHz, DMSO-d6) (d, ppm): 7.50 (1H, s, ArH), 7.55–7.67 (3H, m,
ArH), 7.70 (1H, d, J = 7.6 Hz, ArH), 7.96 (2H, s, NH2), 11.22 (1H, br, NH). Anal.
Calcd. for C11H8N6O2: C, 51.56; H, 3.15; N, 32.80. Found: C, 51.40; H, 3.18; N,
32.63.
HRMS m/z calculated for C11H8N6O2 [M]?: 256.0709, found: 256.0683.
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An efficient and facile synthesis of novel substituted pyrimidine derivatives
2439
4-Amino-5-carbonitrile -6-(4-fluorophenyl)-2-nitroaminopyrimidine (4b)
Melting point[290 °C; IR (KBr, m, cm-1): 3,338, 3,116, 2,750, 2,215, 1,684, 1,653,
1,608, 1,510, 1,476, 1,235, 1,167, 1,131, 1,013, 933, 846, 807, 776, 672, 619 cm-1
;
1H NMR (400 MHz, DMSO-d6) (d, ppm): 7.42 (2H, q, J = 8.4 Hz, ArH), 7.57 (1H,
dd, J = 6.4 Hz, J = 7.2 Hz, ArH), 7.78 (1H, t, J = 6.8 Hz, ArH), 7.96 (2H, s,
NH2), 11.92 (1H, br, NH). Anal. Calcd. for C11H7FN6O2: C, 48.18; H, 2.57; N,
30.65. Found: C, 48.32; H, 2.52; N, 30.73.
HRMS m/z calculated for C11H7FN6O2 [M-H]?: 273.0537, found: 273.0545.
4-Amino-5-carbonitrile -6-(4-chlorophenyl)-2-nitroaminopyrimidine (4c)
Melting point 244–245 °C; IR (KBr, m, cm-1): 3,345, 3,105, 2,871, 2,765, 2,224,
2,189, 1,668, 1,531, 1,472, 1,455, 1,372, 1,298, 1,229, 1,123, 1,061, 1,038, 1,015,
1
951, 748 cm-1; H NMR (400 MHz, DMSO-d6) (d, ppm): 7.41 (1H, s, ArH), 7.52
(1H, dd, J = 6.8 Hz, J = 7.2 Hz, ArH), 7.61–7.68 (2H, m, ArH), 7.96 (2H, s, NH2),
11.22 (1H, br, NH). Anal. Calcd. for C11H7ClN6O2: C, 45.45; H, 2.43; N, 28.91.
Found: C, 45.60; H, 2.46; N, 28.82.
HRMS m/z calculated for C11H7ClN6O2 [M ? Na]?: 313.0217, found: 313.0219.
4-Amino-5-carbonitrile-6-(2,4-dichlorophenyl)-2-nitroaminopyrimidine (4d)
Melting point[280 °C; IR (KBr, m, cm-1): 3,446, 2,217, 1,647, 1,578, 1,474, 1,375,
1
1,315, 1,103, 781, 669, 657 cm-1; H NMR (400 MHz, DMSO-d6) (d, ppm): 7.53
(1H, d, J = 7.2 Hz, ArH), 7.63 (1H, d, J = 8.4 Hz, ArH), 7.67–7.74 (1H, m, ArH),
7.95 (2H, s, NH2), 11.20 (1H, br, NH). Anal. Calcd. for C11H6Cl2N6O2: C, 40.64; H,
1.86; N, 25.85. Found: C, 40.40; H, 1.88; N, 25.77.
HRMS m/z calculated for C11H6Cl2N6O2 [M ? Na]?: 346.9827, found:
346.9829.
4-Amino-5-carbonitrile-6-(3,4-dichlorophenyl)-2-nitroaminopyrimidine (4e)
Melting point[290 °C; IR (KBr, m, cm-1): 3,422, 2,736, 2,210, 1,655, 1,591, 1,541,
1
1,474, 1,439, 1,386, 1,350, 1,264, 1,094, 1,030, 773, 760, 669 cm-1; H NMR
(400 MHz, DMSO-d6) (d, ppm): 7.51 (1H, d, J = 8.4 Hz, ArH), 7.82–7.84 (2H, m,
ArH), 7.95 (2H, s, NH2), 11.21 (1H, br, NH). Anal. Calcd. for C11H6Cl2N6O2: C,
40.64; H, 1.86; N, 25.85. Found: C, 40.81; H, 1.83; N, 25.98.
HRMS m/z calculated for C11H6Cl2N6O2 [M ? H]?: 325.0008, found: 325.0002.
4-Amino-5-carbonitrile-6-(4-bromophenyl)-2-(nitroamino)pyrimidine (4f)
Melting point[290 °C; IR (KBr, m, cm-1): 3,345, 3,102, 2,743, 2,216, 1,682, 1,651,
1,633, 1,598, 1,540, 1,493, 1,474, 1,437, 1,397, 1,299, 1,267, 1,230, 1,159, 1,130,
1
1,009, 941, 833, 782, 774, 668, 622 cm-1; H NMR (400 MHz, DMSO-d6) (d,
ppm): 7.46 (1H, d, J = 7.6 Hz, ArH), 7.65 (1H, d, J = 8.4 Hz, ArH), 7.78 (2H, t,
123

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S. Xia et al.
J = 7.6 Hz, ArH), 7.95 (2H, s, NH2), 11.23 (1H, br, NH). Anal. Calcd. for
C11H7BrN6O2: C, 39.42; H, 2.11; N, 25.08. Found: C, 39.56; H, 2.13; N, 25.15.
HRMS m/z calculated for C11H7BrN6O2 [M-H]?: 332.9736, found: 332.9727.
4-Amino-5-carbonitrile-2-(nitroamino)-6-p-tolylpyrimidine (4g)
Melting point[290 °C; IR (KBr, m, cm-1):3,329, 3,125, 2,871, 2,675, 2,216, 1,719,
1,701, 1,686, 1,655, 1,637, 1,542, 1,509, 1,475, 1,438, 1,407, 1,302, 1,234,
1,132 cm-1; 1H NMR (400 MHz, DMSO-d6) (d, ppm): 2.39 (3H, s, CH3), 7.37 (2H,
d, J = 8.0 Hz, ArH), 7.59 (2H, d, J = 8.0 Hz, ArH), 7.97 (2H, s, NH2), 11.97 (1H,
br, NH). Anal. Calcd. for C12H10N6O2: C, 53.33; H, 3.73; N, 31.10. Found: C,
53.46; H, 3.70; N, 31.19.
HRMS m/z calculated for C12H10N6O2 [M]?: 270.0865, found: 270.0828.
4-Amino-5-carbonitrile-6-(3,4-dimethylphenyl)-2-nitroaminopyrimidine (4h)
Melting point[290 °C; IR (KBr, m, cm-1): 3,347, 3,141, 2,877, 2,761, 2,216, 1,681,
1,654, 1,542, 1,499, 1,475, 1,289, 1,269, 1,156, 1,123, 1,027, 894, 834, 781,
670 cm-1; 1H NMR (400 MHz, DMSO-d6) (d, ppm): 2.29 (3H, s, CH3), 2.31 (3H, s,
CH3), 7.19–7.25 (1H, m, ArH), 7.32 (1H, t, J = 8.8 Hz, ArH), 7.42–7.50 (1H, m,
ArH), 7.96 (2H, s, NH2), 11.82 (1H, br, NH). Anal. Calcd. for C13H12N6O2: C,
54.93; H, 4.25; N, 29.56. Found: C, 54.69; H, 4.30; N, 29.47.
HRMS m/z calculated for C13H12N6O2 [M]?: 284.1022, found: 284.1031.
4-Amino-5-carbonitrile-6-(2-methoxyphenyl)-2-nitroaminopyrimidine (4i)
Melting point[290 °C; IR (KBr, m, cm-1): 3,327, 3,082, 2,759, 2,222, 1,698, 1,669,
1,601, 1,535, 1,483, 1,433, 1,273, 1,247, 1,164, 1,131, 1,120, 1,051, 1,011, 919,
757, 670 cm-1; 1H NMR (400 MHz, DMSO-d6) (d, ppm): 3.82 (3H, s, OCH3), 7.01
(2H, t, J = 7.2 Hz, ArH), 7.28 (1H, d, J = 7.6 Hz, ArH), 7.51 (1H, t, J = 8.0 Hz,
ArH), 7.88 (2H, s, NH2), 11.79 (1H, br, NH). Anal. Calcd. for C12H10N6O3: C,
50.35; H, 3.52; N, 29.36. Found: C, 50.55; H, 3.54; N, 29.29.
HRMS m/z calculated for C12H10N6O3 [M-H]?: 285.0736, found: 285.0766.
4-Amino-5-carbonitrile-6-(4-methoxyphenyl)-2-nitroaminopyrimidine (4j)
Melting point 252–253 °C; IR (KBr, m, cm-1): 3,345, 3,126, 2,766, 2,231, 1,719,
1,700, 1,637, 1,543, 1,510, 1,431, 1,399, 1,374, 1,315, 1,185, 1,121 cm-1; 1H NMR
(400 MHz, DMSO-d6) (d, ppm): 3.71 (3H, s, OCH3), 6.84 (2H, d, J = 8.4 Hz,
ArH), 7.13 (2H, d, J = 8.4 Hz, ArH), 7.96 (2H, s, NH2), 12.70 (1H, br, NH). Anal.
Calcd. for C12H10N6O3: C, 50.35; H, 3.52; N, 29.36. Found: C, 50.42; H, 3.50; N,
29.44.
HRMS m/z calculated for C12H10N6O3 [M-H]?: 285.0736, found: 285.0759.
123

An efficient and facile synthesis of novel substituted pyrimidine derivatives
2441
4-Amino-5-carbonitrile-6-(2,5-dimethoxyphenyl)-2-nitroaminopyrimidine (4k)
Melting point 229–230 °C; IR (KBr, m, cm-1): 3,447, 3,127, 2,835, 2,216, 1,633,
1
1,590, 1,505, 1,428, 1,350, 1,302, 1,222, 1,123, 1,039, 809, 759, 669 cm-1; H
NMR (400 MHz, DMSO-d6) (d, ppm): 3.76 (3H, s, OCH3), 3.79 (3H, s, OCH3),
6.48 (1H, t, J = 6.4 Hz, ArH), 6.91 (1H, t, J = 8.8 Hz, ArH), 7.14 (1H, t,
J = 8.8 Hz, ArH), 7.81 (2H, m, NH2), 11.80 (1H, br, NH). Anal. Calcd. for
C13H12N6O4: C, 49.37; H, 3.82; N, 26.57. Found: C, 49.53; H, 3.85; N, 26.49.
HRMS m/z calculated for C13H12N6O4 [M ? Na]?: 339.0818, found: 339.0811.
4-Amino-5-carbonitrile-6-(3,4-dimethoxyphenyl)-2-nitroaminopyrimidine (4l)
Melting point 272–273 °C; IR (KBr, m, cm-1): 3,328, 3,169, 2,939, 2,841, 2,755,
2,214, 1,677, 1,599, 1,519, 1,481, 1,328, 1,267, 1,145, 1,021, 868, 807, 767,
670 cm-1; 1H NMR (400 MHz, DMSO-d6) (d, ppm): 3.80 (3H, s, OCH3), 3.84 (3H,
s, OCH3), 7.07–7.13 (3H, m, ArH), 7.83 (2H, m, NH2) 11.97 (1H, br, NH). Anal.
Calcd. for C13H12N6O4: C, 49.37; H, 3.82; N, 26.57. Found: C, 49.50; H, 3.87; N,
26.62.
HRMS m/z calculated for C13H12N6O4 [M]?: 316.0920, found: 316.0909.
4-Amino-5-carbonitrile-2-nitroamino-6-(3,4,5-trimethoxyphenyl)pyrimidine (4m)
Melting point[290 °C; IR (KBr, m, cm-1): 3,374, 3,117, 2,763, 2,211, 1,698, 1,684,
1,542, 1,509, 1,416, 1,360, 1,321, 1,255, 1,183, 1,130, 995, 852, 772, 721,
669 cm-1; 1H NMR (400 MHz, DMSO-d6) (d, ppm): 3.74 (3H, s, OCH3), 3.82 (3H,
s, OCH3), 3.84 (3H, s, OCH3), 6.84 (1H, s, ArH), 7.08 (1H, s, ArH), 8.07 (2H, s,
NH2), 11.80 (1H, br, NH). Anal. Calcd. for C14H14N6O5: C, 48.56; H, 4.07; N,
24.27. Found: C, 48.29; H, 4.08; N, 24.35.
HRMS m/z calculated for C14H14N6O5 [M]?: 346.1026, found: 346.1037.
4-Amino-6-(benzo[d] [1, 3]dioxol-5-carbonitrile-5-yl)-2-nitroaminopyrimidine (4n)
Melting point[290 °C; IR (KBr, m, cm-1): 3,449, 3,150, 3,057, 2,216, 1,684, 1,558,
1,492, 1,447, 1,359, 1,256, 1,103, 1,034, 926, 866, 815, 781, 748, 669, 655,
1
525 cm-1; H NMR (400 MHz, DMSO-d6) (d, ppm): 6.16 (2H, s, OCH2O), 7.10
(1H, d, J = 8.0 Hz, ArH), 7.25 (1H, d, J = 8.0 Hz, ArH), 7.87 (1H, s, ArH), 7.96
(2H, s, NH2), 11.72 (1H, br, NH). Anal. Calcd. for C12H8N6O4: C, 48.01; H, 2.69; N,
27.99. Found: C, 48.23; H, 2.72; N, 27.91.
HRMS m/z calculated for C12H8N6O4 [M]?: 300.0607, found: 300.0597.
4-Amino-5-carbonitrile-6-(naphthalene-1-yl)-2-nitroaminopyrimidine (4o)
Melting point[290 °C; IR (KBr, m, cm-1): 3,461, 3,152, 2,215, 1,646, 1,586, 1,508,
1,488, 1435, 801, 777, 669 cm-1 1H NMR (400 MHz, DMSO-d6) (d, ppm):
;
7.51–7.54 (3H, m, ArH), 7.71 (1H, d, J = 9.2 Hz, ArH), 7.76 (1H, dd, J = 1.6 Hz,
J = 6.4 Hz, ArH), 7.82 (1H, d, J = 8.0 Hz, ArH), 7.91 (1H, s, ArH), 7.96 (2H, s,
123

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S. Xia et al.
NH2), 11.95 (1H, s, NH). Anal. Calcd. for C15H10N6O2: C, 58.82; H, 3.29; N, 27.44.
Found: C, 58.56; H, 3.25; N, 27.58.
HRMS m/z calculated for C15H10N6O2 [M-H]? 305.0787, found: 305.0825.
Acknowledgments We are grateful to the National Natural Science Foundation of China (NSFC)
(21172188), the Foundation of Jiangsu Normal University (10XLS02) and Priority Academic Program
Development of Jiangsu Higher Education Institutions for financial support.
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