Synthesis of ammonium 3,5-dicyano-4-aryl-2,6-pyridinedionates with one-pot reaction of aromatic aldehydes, amines, and cyanoacetamide

Article abstract of DOI:10.1080/00397911.2011.636497

A simple and efficient synthesis of ammonium 3,5-dicyano-4-aryl-2,6- pyridinedionates was accomplished via one-pot, three-component reaction of aromatic aldehydes, amines, and cyanoacetamide. This unprecedented methodology had some potential advantages such as the common available starting material, short reaction time, good yield, broad substrate scope, and convenient operation.

Full text of DOI:10.1080/00397911.2011.636497

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Synthesis of Ammonium 3,5-Dicyano-4-
aryl-2,6-pyridinedionates with One-Pot
Reaction of Aromatic Aldehydes, Amines,
and Cyanoacetamide
Ying Han a , Er-Yan Xia a , Qun Wu a , Jing Sun a & Chao-Guo Yan a
a College of Chemistry and Chemical Engineering, Yangzhou
University, Yangzhou, China
Accepted author version posted online: 05 Jun 2012.Version of
record first published: 05 Mar 2013.
To cite this article: Ying Han , Er-Yan Xia , Qun Wu , Jing Sun & Chao-Guo Yan (2013): Synthesis of
Ammonium 3,5-Dicyano-4-aryl-2,6-pyridinedionates with One-Pot Reaction of Aromatic Aldehydes,
Amines, and Cyanoacetamide, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 43:10, 1413-1424
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Synthetic Communications1, 43: 1413–1424, 2013
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2011.636497
SYNTHESIS OF AMMONIUM 3,5-DICYANO-4-ARYL-
2,6-PYRIDINEDIONATES WITH ONE-POT REACTION
OF AROMATIC ALDEHYDES, AMINES, AND
CYANOACETAMIDE
Ying Han, Er-Yan Xia, Qun Wu, Jing Sun, and Chao-Guo Yan
College of Chemistry and Chemical Engineering, Yangzhou University,
Yangzhou, China
GRAPHICAL ABSTRACT
Abstract A simple and efficient synthesis of ammonium 3,5-dicyano-4-aryl-2,6-pyridinedio-
nates was accomplished via one-pot, three-component reaction of aromatic aldehydes,
amines, and cyanoacetamide. This unprecedented methodology had some potential advan-
tages such as the common available starting material, short reaction time, good yield, broad
substrate scope, and convenient operation.
Keywords Aromatic amine; cyanoacetamide; Knoevenagel reaction; one-pot reaction;
pyridinedione
INTRODUCTION
Cyanoacetamide is both a typical active methylene compound and a polyfuc-
tional substrate because of the presence of very useful cyano and amido groups.
Cyanoacetamides have been used as potentially versatile components in many
condensation and multicomponent reactions.[1–6] It has long been known that the
basic- catalyzed reaction of aldehyde with cyanoacetamide gives the Knoevenagel
condensation product (arylidenecyanoacetamide).[7–9] In past years, significant
efforts have been directed toward a more efficient method for this condensation,
which included different kinds of catalyst[10–14] and the use of environmentally
benign solvents such as water, ionic liquid, and solvent-free reactions.[13–18] The
synthesis of the substituted 2-pydidiones from reaction of cyanoacetamide with
a,b-unsaturated ketones and three-component reaction of cyanoacetamide with
aldehydes and ketones have attracted much attention.[19–24] Recently we found one
sequential reaction of aromatic aldehyde, cyanoacetamide, and pyridinium salt gives
Received May 30, 2010.
Address correspondence to Chao-Guo Yan, College of Chemistry and Chemical Engineering,
Yangzhou University, Yangzhou 225002, China. E-mail: cgyan@yzu.edu.cn
1413

1414
Y. HAN ET AL.
polysubstituted cyclopropanes.[25] In continuation of our research aim of developing
more efficient and environmentally benign reactions for construction of heterocyclic
system, here we report the efficient synthesis of polysubstituted ammonium salts of
2,6-pyridinedione via three-component reaction of aromatic aldehydes, aliphatic
amine, and cyanoacetamide.
RESULTS AND DISCUSSION
Our investigation started with the three-component reaction of benzaldehyde,
cyanoacetamide, and pyrrolidine. The mixture of equal molecular parts of benzal-
dehyde, cyanoacetamide, and pyrrolidine in acetonitrile was stirred at about 40–50 ꢀC
for two days. The resulting precipitates were collected and structures were deter-
1
mined by H NMR and mass (MS) spectra and further confirmed by x-ray single-
crystal analysis. We were very surprised to find that one unexpected pyrrolidinium
salt of 3,5-dicycano-4-phenyl-2,6-pyridinedione 1a was formed in 40% yield. The
reaction can be carried out in other solvents such as methanol, ethanol and dioxane.
Similar results were obtained, and the greatest yield of 1a was obtained in dioxane
(51%). It should be pointed out that the ammonium salt has some solubility in these
solvents, which caused the yields to be lower. Subsequently, a variety of aromatic
aldehydes with different substituents were tested in dioxane as solvent. The results
are shown in Table 1. From the results, we could see that all reactions proceeded
smoothly to afford the corresponding pyrrolidinium salt of 3,5-dicycano-4-phenyl-
2,6-pyridinediones (1b–1h) in moderate yields (53–62%). This surprising result is of
value to us not only because we are interested in the design of the new multicompo-
nent reaction but also because we were unable to find examples of other methods
allowing for such convenient synthesis in the related literature. To the best of our
knowledge, only similar trans-4,5-substituted 1,4,5,6-tetrahydropyridine-2-(olates)
were prepared from the reaction of (N-carbomoylmethyl)-pyridinium salts with aro-
matic aldehydes and cyanoacetamide in the presence of triethylamine.[26] Another
similar reaction is the Guareschi reaction of ketone, cyanoacetate, and amine to
form ammonium salt of 3,5-dicyano-4-phenyl-2,6-pyridinedione.[27–29]
Table 1. Synthesis of pyrrolidinium polysusbstituted 2,6-pyridinedionates
Entry
Compound
R2
Ar
Yield (%)
1
2
3
4
5
6
7
8
1a
1b
1c
1d
1e
1f
(CH2)4
(CH2)4
(CH2)4
(CH2)4
(CH2)4
(CH2)4
(CH2)4
(CH2)4
C6H5
p-CH3C6H4
p-(CH3)2CHC6H4
p-(CH3)3CC6H4
m-ClC6H4
51
56
53
60
56
62
61
55
p-ClC6H4
p-BrC6H4
m-NO2C6H4
1g
1h

AMMONIUM 3,5-DICYANO-4-ARYL-2,6-PYRIDINEDIONATES
1415
Figure 1. Molecular structure of compound 1a.
The structures of these ammonium salts of 2,6-pyridinediones 1a–1h were fully
1
characterized by H and 13C NMR, MS, and infrared (IR) spectra. Because of the
very hygroscopic property of the sample, it is difficult to get satisfactory elemental
1
analytical data. For example, in the H NMR spectra of 1a, the one proton of dii-
mide shows one broad singlet at 10.60 ppm and the two protons of pyrrolidinium
cation display one broad peak at 8.30 ppm. The x-ray diffraction determination of
single crystals of 1a (Fig. 1) further confirmed that the negative charge is located
on the C-8 carbon atom and delocalized onto the C-12 through the 1,3-allyl system,
but not on the nitrogen atom of the diimide unit. There is one hydrogen atom
attached the nitrogen atom and no hydrogen atom connected with the two carbon
atoms bearing with the cyano groups. The two C-O bond distances [C10–O2
˚
˚
=
1.2479(18) A and C11–O1 1.2446(17) A] are within the C O distances. The bond dis-
˚
˚
tance of C7–C8 [1.4010(19) A] and C7–C12 [1.4011(19) A] are nearly same, which
obviously shows C8–C7–C12 forming an 1,3-allyl system. 2,6-Pyridinedione has rela-
tively stronger acidity and exists usually in equilibrium with its enol form, 2,6-dihy-
droxypyridine. Here, because of the existence of two stronger electron-withdrawing
cyano groups, the acidity was increased greatly and the whole molecule exists in
ketoform.
Then the reactivity of other secondary amines such as perpiridine, morphiline,
diethylamine, and diisopropylamine were also tested in the reaction and similar
ammonium salts 2a–2n were produced as main products in better yields (56–82%,
see Table 2). It is also pleasing to find that a typical tertiary amine such as triethyl-
amine and 1,4-diazabicyclo[2.2.2]octane (DABCO) gave the ammonium salts 2o–2t
in moderate yields (41–68%). The structures of the obtained ammonium salts of
1
2,6-pyridinediones 2a–2t were established on the basis of H and 13C NMR, MS,
and IR spectra and determination of three single-crystal structures of 2e, 2h, and
2t. These results demonstrated that this reaction has great generality. Thus, our
present protocol provides an efficient method for the synthesis of ammonium salts
of polysubstituted 2,6-dicyanopyridinediones from the one-pot, three-component
reaction of aromatic aldehyde, amine and cyanoacetamide.

1416
Y. HAN ET AL.
Table 2. Synthesis of ammonium polysusbstituted 2,6-pyridinedionates
Entry
Compound
R3N
Ar
Yield (%)
1
2
2a
2b
2c
2d
2e
2f
(CH2)5NH
(CH2)5NH
(CH2)5NH
(CH2)5NH
(CH2)5NH
(CH2)5NH
O(CH2CH2)2NH
O(CH2CH2)2NH
O(CH2CH2)2NH
O(CH2CH2)2NH
O(CH2CH2)2NH
O(CH2CH2)2NH
Et2NH
C6H5
p-CH3C6H4
p-(CH3)2CHC6H4
p-(CH3)3CC6H4
p-ClC6H4
52
65
68
56
72
74
68
70
75
75
82
70
45
51
41
60
58
57
65
68
62
3
4
5
6
p-BrC6H4
C6H5
7
2 g
2 h
2i
8
p-CH3C6H4
p-(CH3)3CC6H4
p-ClC6H4
9
10
11
12
13
14
15
16
17
18
19
20
21
2j
2k
2 l
2 m
2n
2o
2p
2q
2r
p-BrC6H4
m-NO2C6H4
p-(CH3)3CC6H4
p-(CH3)2CHC6H4
C6H5
i-Pr2NH
Et3N
Et3N
Et3N
p-ClC6H5
p-BrC6H5
DABCO
DABCO
p-(CH3)3CC6H4
p-ClC6H4
p-BrC6H4
2s
2t
DABCO
DABCO
2r
p-BrC6H4
To explain the formation of unexpected product via this one-pot, multicompo-
nent reaction, we propose a plausible reaction mechanism, which is illustrated in
Scheme 1. The first step is obviously the basic catalytic Knoevenagel condensation
of cyanoacetamide with aromatic aldehyde to form arylidenecyanoacetamide (A).
Figure 2. Molecular structure of compound 2u.

AMMONIUM 3,5-DICYANO-4-ARYL-2,6-PYRIDINEDIONATES
1417
Scheme 1. Formation mechanism for ammonium 2,6-pyridinedionate.
Then the Michael addition of excess cyanoacetamide to arylidenecyanoacetamide
(A) forms the double adduct intermediate (B). Intermediate B is a substituted dia-
mide, which is easily transformed to substituted cyclic glutarimide (C) by losing
one molecular ammonia. In basic solution glutarimide (C) was deprotonated and
oxidized in air to give the final products. To form an aromatic system, the easily
dehydrogenation is a very common step in cyclization reaction.[25,30] To probe the
credibility of our proposed mechanistic scheme and shed more light on the formation
of the ammonium polysubstituted 2,6-pyridinedionates, further experiments were
carried out. The three component reaction of equal molecular ratio of piperidine,
cyanoacetamide, and previously prepared ethyl 4-chlorobenzylidene cyanoacetate
in dioxane gave the ammonium salt 2e in 47% yield. Here the formation of 2e clearly
involved the process of basic catalytic Michael addition of cyanoacetamide to
4-chlorobenzylidene cyanoacetate to form the similar intermediates B (in which
one amino group is replaced by ethoxy group) and C.
CONCLUSIONS
In summary we have demonstrated that the one-pot, three-component reac-
tions of cyanoacetamide, aromatic aldehydes, and amines gave ammonium polysub-
stituted 2,6-pyridinedionates in good yields. The advantages of this approach are as
follows: the starting materials are commercially available reagents. The reaction
procedure is convenient, involving a simple experimental procedure and product
isolation, and dispenses with extensive recrystallization and chromatographic purifi-
cation steps.
EXPERIMENTAL
All the reactions were monitored by thin-layer chromatography (TLC).
Melting points were taken on a hot-plate microscope apparatus. IR spectra were
obtained on a Bruker Tensor 27 spectrometer (KBr disc). NMR spectra were
recorded with a Bruker AV-600 spectrometer with dimethylsulfoxide (DMSO-d6)

1418
Y. HAN ET AL.
as solvent and tetramethylsilane (TMS) as internal standard (600 and 150 MHz for
1H and 13C NMR spectra, respectively). High-performance liquid chranatography
(HPLC)=MS were measured at Fennigan LCQ Deca XP MAX instrument. X-ray
data were collected on a Bruker Smart APEX-2 CCD diffractometer. Aromatic alde-
hydes, cyanoacetoamide, amine, and other reagents are commercial reagents and
used as received. Solvents were purified by standard techniques.
General Procedure of One-Pot, Four-Component Reaction
Involving 1,3-Thiazolidinedione, Aromatic Aldehydes, Malononitrile,
and Amine
A mixture of aromatic aldehyde (4.0 mmol), cyanoacetamide (4.0 mmol,
0.336 g), and organic amine (4.0 mmol, 0.34 g) in dioxane (5.0 mL) was stirred at
40–50 ꢀC for 48 h. The resulting precipitate was collected by filtration and washed
with some acetonitrile to give the pure product for analysis.
Selected Data
Compound 1a. Mp: >250 ꢀC; IR (KBr) t: 3104, 2960, 2799, 2209, 1604, 1517,
1469, 1406, 1246, 1223, 1181, 1106, 1031, 872, 853, 787, 769 cmꢁ1 1H NMR
;
(600 MHz, DMSO-d6) d: 10.60 (brs, 1H, NH), 8.30 (brs, 2H, NHþ2 ), 7.46 (s, 3H,
ArH), 7.39 (s, 2H, ArH), 3.09 (s, 4H, CH2), 1.82 (s, 4H, CH2); 13C NMR
(150 MHz, DMSO-d6) d: 163.5, 162.0, 136.4, 129.1, 128.2, 127.8, 118.7, 81.7, 44.9,
23.6. MS (m=z): 236.66 ([M-C4H10N]þ) 100%.
Compound 1b. Mp: >250 ꢀC; IR (KBr) t: 3106, 2963, 2797, 2207, 1749,
1702, 1607, 1477, 1407, 1327, 1307, 1244, 1225, 1189, 1152, 1116, 1024, 873, 823,
1
775, 752 cmꢁ1; H NMR (600 MHz, DMSO-d6) d: 10.57 (s, 1H, NH), 8.53 (brs,
2H, NHþ2 ), 7.27 (s, 4H, ArH), 3.09 (s, 4H, CH2), 2.36 (s, 3H, CH3), 1.83 (s, 4H,
CH2); 13C NMR (150 MHz, DMSO-d6) d: 174.6, 173.6, 163.5, 162.0, 138.7, 133.5,
128.7, 127.8, 118.8, 81.7, 44.9, 36.0, 23.6, 20.8. MS (m=z): 250.69 ([M-C4H10N]þ)
100%.
Compound 1c. Mp: >250 ꢀC; IR (KBr) t: 3105, 2960, 2798, 2208, 1653, 1603,
1512, 1470, 1405, 1248, 1221, 1100, 1056, 844, 829, 777, 747 cmꢁ1 1H NMR
;
(600 MHz, DMSO-d6) d: 10.56 (brs, 1H, NH), 8.17 (brs, 2H, NHþ2 ), 7.34–7.31 (m,
4H, ArH), 3.09–3.07 (m, 4H, CH2), 2.97–2.92 (m, 1H, CH), 1.83–1.81 (m, 4H,
CH2), 1.25–1.23 (m, 6H, CH3); 13C NMR (150 MHz, DMSO-d6) d: 163.5, 161.8,
149.4, 133.7, 127.9, 126.1, 118.9, 81.6, 44.9, 33.2, 23.7, 23.6. MS (m=z): 278.54
([M-C4H10N]þ) 100%.
Compound 1d. Mp: >250 ꢀC; IR (KBr) t: 3103, 2961, 2800, 2206, 1603,
1512, 1471, 1408, 1366, 1268, 1249, 1222, 1106, 1029, 873, 841, 777 cmꢁ1 1H
;
NMR (600 MHz, DMSO-d6) d: 10.57 (brs, 1H, NH), 8.24 (brs, 2H, NHþ2 ), 7.49
(d, J ¼ 8.4 Hz, 2H, ArH), 7.34 (d, J ¼ 8.4 Hz, 2H, ArH), 3.10–3.08 (m, 4H, CH2),
1.84–1.81 (m, 4H, CH2), 1.32 (s, 9H, CH3); 13C NMR (150 MHz, DMSO-d6) d:
163.5, 161.7, 151.6, 133.4, 127.7, 124.9, 118.9, 81.5, 44.9, 34.5, 31.0, 23.6. MS (m=
z): 292.51 ([M-C4H10N]þ) 100%.

AMMONIUM 3,5-DICYANO-4-ARYL-2,6-PYRIDINEDIONATES
1419
Compound 1e. Mp: >250 ꢀC; IR (KBr) t: 3085, 2950, 2787, 2210, 1630, 1513,
1
1465, 1408, 1240, 1223, 1098, 1080, 920, 847, 803, 777, 760, 750 cmꢁ1; H NMR
(600 MHz, DMSO-d6) d: 10.65 (brs, 1H, NH), 8.29 (brs, 2H, NHþ2 ), 7.54–7.49 (m,
2H, ArH), 7.46 (s, 1H, ArH), 7.36 (d, J ¼ 6.6 Hz, 1H, ArH), 3.09 (t, J ¼ 7.2 Hz,
4H, CH2), 1.84–1.81 (m, 4H, CH2); 13C NMR (150 MHz, DMSO-d6) d: 163.2,
160.3, 138.4, 132.8, 130.2, 129.0, 127.5, 126.6, 118.4, 81.7, 44.9, 23.6. MS (m=z):
270.62 ([M-C4H10N]þ) 100%.
Compound 1f. Mp: >250 ꢀC; IR (KBr) t: 3391, 3092, 2963, 2799, 2210, 1610,
1
1514, 1468, 1402, 1244, 1222, 1147, 1094, 1019, 886, 834, 776, 751 cmꢁ1; H NMR
(600MHz, DMSO-d6) d: 10.65 (s, 1H, NH), 8.48 (s, 2H, NHþ2 ), 7.54 (d, J ¼ 7.8 Hz,
2H, ArH), 7.42 (d, J ¼ 7.8 Hz, 2H, ArH), 3.09 (t, J ¼ 6.6 Hz, 4H, CH2), 1.83 (s, 4H,
CH2); 13C NMR (150MHz, DMSO-d6) d: 163.2, 160.7, 135.3, 133.9, 129.8, 128.3,
118.6, 81.6, 44.9, 23.6. MS (m=z): 270.78 ([M-C4H10N]þ) 100%.
Compound 1g. Mp: >250 ꢀC; IR (KBr) t: 3110, 2963, 2799, 2211, 1661,
1603, 1516, 1467, 1403, 1246, 1221, 1106, 1073, 1014, 978, 917, 884, 834, 822, 775,
1
750 cmꢁ1; H NMR (600 MHz, DMSO-d6) d: 10.64 (brs, 1H, NH), 8.26 (brs, 2H,
NHþ2 ), 7.68 (d, J ¼ 8.4 Hz, 2H, ArH), 7.35 (d, J ¼ 8.4 Hz, 2H, ArH), 3.09 (t,
J ¼ 7.2 Hz, 4H, CH2), 1.84–1.81 (m, 4H, CH2); 13C NMR (150 MHz, DMSO-d6)
d: 163.2, 160.7, 135.7, 131.3, 130.0, 122.5, 118.5, 81.5, 44.9, 23.6; MS (m=z):
314.89 ([M-C4H10N]þ) 100%.
Compound 1h. Mp: 228–230 ꢀC; IR (KBr) t: 3451, 3103, 2972, 1806, 2208,
1637, 1522, 1468, 1416, 1350, 1247, 1160, 1110, 1086, 1031, 877, 778 cmꢁ1 1H
;
NMR (600 MHz, DMSO-d6)) d: 10.74 (brs, 1H, NH), 8.34 (s, 1H, ArH), 8.26 (s,
1H, ArH), 7.91 (s, 1H, ArH), 7.81 (s, 1H, ArH), 3.10 (s, 4H, CH2), 1.83 (s, 4H,
CH2); 13C NMR (150 MHz, DMSO-d6)) d: 163.2, 159.5, 147.4, 137.8, 134.7, 130.2,
124.1, 122.7, 118.4, 81.8, 66.3, 45.0, 23.6; MS (m=z): 281.12 ([M-C4H10N]þ) 100%.
Compound 2a. Mp: >250 ꢀC; IR (KBr) t: 3071, 2945, 2861, 2809, 2205, 1655,
1621, 1513, 1470, 1433, 1410, 1393, 1300, 1244, 1226, 1180, 1154, 1080, 1034, 947,
892, 867, 808, 785, 768 cmꢁ1 1H NMR (600 MHz, DMSO-d6) d: 10.61 (s, 1H,
;
NH), 8.22 (s, 2H, NHþ2 ), 7.47–7.44 (m, 3H, ArH), 7.39–7.38 (m, 3H, ArH), 3.01
(t, J ¼ 6.0 Hz, 4H, CH2), 1.65–1.61 (m, 4H, CH2), 1.56–1.53 (m, 2H, CH2); 13C
NMR (150 MHz, DMSO-d6) d: 163.4, 161.9, 136.4, 129.1, 128.2, 127.8, 118.7,
81.6, 43.8, 22.2, 21.6. MS (m=z): 236.46 ([M-C5H12N]þ) 100%.
Compound 2b. Mp: >250 ꢀC; IR (KBr) t: 3098, 2954, 2856, 2801, 2536,
2438, 2214, 1613, 1509, 1473, 1411, 1222, 1186, 1113, 1031, 947, 903, 820, 777,
1
751 cmꢁ1; H NMR (600MHz, DMSO-d6) d: 7.28 (s, 4H, ArH), 3.01 (t, J ¼ 6.0 Hz,
4H, CH2), 2.37 (s, 3H, CH3), 1.67–1.63 (m, 4H, CH2), 1.57–1.53 (m, 2H, CH2); 13C
NMR (150 MHz, DMSO-d6) d: 163.5, 162.2, 138.9, 133.3, 128.8, 127.7, 118.7, 81.8,
43.7, 22.0, 21.5, 20.8. MS (m=z): 250.66 ([M-C5H12N]þ) 100%.
Compound 2c. Mp: >250 ꢀC; IR (KBr) t: 3102, 2959, 2798, 2206, 1625, 1595,
1
1509, 1478, 1413, 1307, 1245, 1224, 1185, 1155, 1056, 950, 895, 837, 778 cmꢁ1; H
NMR (600 MHz, DMSO-d6) d: 7.36–7.33 (m, 4H, ArH), 3.01 (t, J ¼ 6.0 Hz, 4H,
CH2), 2.98–2.93 (m, 1H, CH), 1.66–1.63 (m, 4H, CH2), 1.57–1.54 (m, 2H, CH2),
1.25 (d, J ¼ 6.6 Hz, 6H, CH3); 13C NMR (150 MHz, DMSO-d6) d: 163.6, 162.0,

1420
Y. HAN ET AL.
149.5, 133.5, 127.9, 126.1, 118.8, 81.7, 43.7, 33.2, 23.6, 22.0, 21.5. MS (m=z): 278.53
([M-C5H12N]þ) 100%.
Compound 2d. Mp: >250 ꢀC; IR (KBr) t: 3080, 2960, 2867, 2204, 1624,
1508, 1474, 1413, 1395, 1295, 1269, 1249, 1224, 1154, 1106, 1082, 1023, 948, 892,
1
837, 778 cmꢁ1. H NMR (600 MHz, DMSO-d6) d: 10.57 (s, 1H, NH), 8.23 (s, 2H,
NHþ2 ), 7.48 (d, J ¼ 8.4 Hz, 2H, ArH), 7.34 (d, J ¼ 7.8 Hz, 2H, ArH), 3.01 (t,
J ¼ 5.4 Hz, 4H, CH2), 1.65–1.62 (m, 4H, CH2), 1.56–1.54 (m, 2H, CH2), 1.32 (s,
9H, CH3); 13C NMR (150 MHz, DMSO-d6) d: 163.5, 161.7, 151.6, 133.3, 127.7,
124.9, 118.9, 81.6, 43.8, 34.5, 31.0, 22.2, 21.6; MS (m=z): 292.62 ([M-C5H12N]þ)
100%.
Compound 2e. Mp: >250 ꢀC; IR (KBr) t: 3090, 2955, 2857, 2796, 2208, 1614,
1
1511, 1471, 1410, 1221, 1112, 1090, 1016, 946, 903, 831, 777, 752 cmꢁ1; H NMR
(600 MHz, DMSO-d6) d: 7.56 (d, J ¼ 7.8 Hz, 2H, ArH), 7.43 (d, J ¼ 7.2 Hz, 2H,
ArH), 3.00 (t, J ¼ 5.4 Hz, 4H, CH2), 1.64–1.63 (m, 4H, CH2), 1.56–1.55 (m, 2H,
CH2); 13C NMR (150 MHz, DMSO-d6) d: 163.6, 160.9, 135.0, 134.0, 129.7, 128.4,
118.4, 81.8, 66.3, 43.7, 22.1, 21.6. MS (m=z): 270.67 ([M-C5H12N]þ) 100%.
Compound 2f. Mp: >250 ꢀC; IR (KBr) t: 3085, 2953, 2857, 2797, 2208, 1613,
1511, 1472, 1412, 1390, 1221, 1150, 1071, 1032, 1011, 947, 905, 883, 828, 777,
1
751 cmꢁ1; H NMR (600 MHz, DMSO-d6) d: 7.69 (d, J ¼ 7.8 Hz, 2H, ArH), 7.37
(d, J ¼ 7.8 Hz, 2H, ArH), 3.00 (t, J ¼ 6.0 Hz, 4H, CH2), 1.66–1.62 (m, 4H, CH2),
1.57–1.55 (m, 2H, CH2); 13C NMR (150 MHz, DMSO-d6) d: 163.6, 160.9, 135.4,
131.3, 129.9, 122.7, 118.4, 81.7, 43.7, 22.1, 21.5. MS (m=z): 315.32 ([M-C5H12N]þ)
97%.
Compound 2g. Mp: >250 ꢀC; IR (KBr) t: 3456, 2988, 2875, 2796, 2528,
2356, 2211, 1623, 1515, 1474, 1410, 1303, 1246, 1225, 1190, 1167, 1104, 1038, 874,
;
848, 823, 785, 767 cmꢁ1 1H NMR (600 MHz, DMSO-d6) d: 7.48–7.49 (m, 3H,
ArH), 7.40 (d, J ¼ 7.8 Hz, 2H, ArH), 3.76 (t, J ¼ 4.2 Hz, 4H, CH2), 3.11 (t,
J ¼ 4.2 Hz, 4H, CH2); 13C NMR (150 MHz, DMSO-d6) d: 163.5, 136.2, 129.3,
128.2, 127.7, 118.6, 81.8, 63.2, 42.8. MS (m=z): 236.58 ([M-C4H10NO]þ) 100%.
Compound 2h. Mp: >250 ꢀC; IR (KBr) t: 3447, 2988, 2793, 2209, 1622,
1508, 1476, 1406, 1301, 1243, 1223, 1190, 1166, 1107, 1040, 978, 869, 844, 824,
776, 754 cmꢁ1 1H NMR (600 MHz, DMSO-d6) d: 7.28 (s, 4H, ArH), 3.76 (t,
.
J ¼ 4.8 Hz, 4H, CH2), 3.10 (t, J ¼ 4.8 Hz, 4H, CH2), 2.37 (s, 3H, CH3). 13C NMR
(150 MHz, DMSO-d6) d: 163.5, 162.2, 138.9, 133.2, 128.8, 127.7, 118.7, 81.8, 63.2,
42.8, 20.8. MS (m=z): 250.73 ([M-C4H10NO]þ) 100%.
Compound 2i. Mp: >250 ꢀC. IR (KBr) t: 3449, 3111, 2963, 2798, 2204, 1629,
1583, 1510, 1477, 1407, 1290, 1269, 1248, 1225, 1200, 1157, 1104, 1043, 1021, 876,
1
838, 779 cmꢁ1. H NMR (600 MHz, DMSO-d6) d: 7.50 (d, J ¼ 7.8 Hz, 2H, ArH),
7.35 (d, J ¼ 7.8 Hz, 2H, ArH), 3.76 (t, J ¼ 3.6 Hz, 4H, CH2), 3.10 (t, J ¼ 4.2 Hz,
4H, CH2), 1.32 (s, 9H, CH3). 13C NMR (150 MHz, DMSO-d6) d: 163.5, 161.8,
151.8, 133.2, 127.6, 124.9, 118.8, 81.6, 63.2, 42.7, 34.4, 31.0. MS (m=z): 292.60
([M-C4H10NO]þ) 100%.

AMMONIUM 3,5-DICYANO-4-ARYL-2,6-PYRIDINEDIONATES
1421
Compound 2j. Mp: >250. IR (KBr) t: 3449, 3093, 2987, 2793, 2481, 2211,
1976, 1586, 1511, 1474, 1409, 1301, 1275, 1243, 1223, 1188, 1165, 1105, 1040,
1
1016, 871, 849, 830, 777, 756 cmꢁ1. H NMR (600 MHz, DMSO-d6) d: 7.56 (d,
J ¼ 7.8 Hz, 2H, ArH), 7.44 (d, J ¼ 7.8 Hz, 2H, ArH), 3.77 (t, J ¼ 4.8 Hz, 4H, CH2),
3.10 (t, J ¼ 4.8 Hz, 4H, CH2). 13C NMR (150 MHz, DMSO-d6) d: 163.3, 160.9,
135.0, 134.0, 129.7, 128.4, 118.5, 81.8, 63.2, 42.8. MS (m=z): 270.79 ([M-C4H10NO]þ)
100%.
Compound 2k. Mp: >250 ꢀC. IR (KBr) t: 3084, 2982, 2789, 2209, 1622, 1685,
1510, 1473, 1407, 1300, 1239, 1218, 1164, 1105, 1076, 1039, 1011, 868, 828, 775 cmꢁ1
.
1H NMR (600 MHz, DMSO-d6) d: 7.70 (d, J ¼ 7.8 Hz, 2H, ArH), 7.37 (t, J ¼ 7.8 Hz,
2H, ArH), 3.77 (t, J ¼ 3.6 Hz, 4H, CH2), 3.11 (t, J ¼ 3.6 Hz, 4H, CH2). 13C NMR
(150 MHz, DMSO-d6) d: 163.3, 160.9, 135.4, 131.3, 129.9, 122.7, 118.5, 81.7, 63.2,
42.8. MS (m=z): 315.11 ([M-C4H10NO]þ) 100%.
Compound 2l. Mp: >250 ꢀC. IR (KBr) t: 3446, 3112, 2976, 2869, 2805, 2207,
1634, 1533, 1467, 1417, 1397, 1354, 1301, 1247, 1224, 1156, 1104, 1043, 929, 871, 845,
817, 726 cmꢁ1. 1H NMR (600 MHz, DMSO-d6) d: 8.35 (d, J ¼ 7.8 Hz, 1H, ArH), 8.26
(s, 1H, ArH), 7.91 (d, J ¼ 7.8 Hz, 1H, ArH), 7.82 (t, J ¼ 7.8 Hz, 1H, ArH), 3.76 (t,
J ¼ 3.6 Hz, 4H, CH2), 3.10 (t, J ¼ 3.6 Hz, 4H, CH2). 13C NMR (150 MHz, DMSO-
d6) d: 163.1, 159.5, 147.4, 137.7, 134.7, 130.3, 124.1, 122.6, 118.3, 81.7, 66.3, 63.2,
42.7. MS (m=z): 281.59 ([M-C4H10NO]þ) 100%.
Compound 2m. Mp: >250 ꢀC. IR (KBr) t: 3469, 3104, 2963, 2862, 2795,
2211, 1615, 1510, 1478, 1414, 1367, 1251, 1223, 1158, 1118, 1045, 874, 836,
1
783 cmꢁ1. H NMR (600 MHz, DMSO-d6) d: 7.50 (d, J ¼ 7.8 Hz, 2H, ArH), 7.35
(d, J ¼ 7.8 Hz, 2H, ArH), 2.92 (q, J ¼ 7.2 Hz, 4H, CH2), 1.33 (s, 9H, CH3), 1.16 (t,
J ¼ 7.2 Hz, 6H, CH3). 13C NMR (150 MHz, DMSO-d6) d: 163.5, 161.9, 151.8,
133.2, 127.7, 127.3, 124.9, 118.8, 81.6, 66.3, 56.0, 41.3, 34.4, 31.0, 18.3, 10.9. MS
(m=z): 292.61 ([M-C4H12N]þ) 100%.
Compound 2n. Mp: >250 ꢀC. IR (KBr) t: 3300, 3107, 2964, 2867, 2795,
2212, 1613, 1589, 1510, 1479, 1404, 1298, 1248, 1222, 1149, 1087, 1055, 1018, 896,
1
833, 808, 783 cmꢁ1. H NMR (600 MHz, DMSO-d6) d: 7.36–7.30 (m, 4H, ArH),
3.38–3.31 (m, 2H, CH), 2.98–2.93 (m, 1H, CH), 1.25 (d, J ¼ 7.2 Hz, 6H, CH3),
1.20 (d, J ¼ 6.0 Hz, 12H, CH3);. 13C NMR (150 MHz, DMSO-d6) d: 163.4, 161.9,
149.5, 133.6, 127.9, 126.1, 118.8, 81.6, 66.3, 46.2, 33.2, 23.6, 18.6. MS (m=z):
278.55 ([M-C6H16N]þ) 100%.
Compound 2o. Mp: >250 ꢀC. IR (KBr) t: 3112, 2998, 2714, 2210, 1625,
1513, 1474, 1379, 1244, 1224, 1181, 1034, 841, 769 cmꢁ1 1H NMR (600 MHz,
.
DMSO-d6) d: 7.48–7.47 (m, 3H, ArH), 7.39 (d, J ¼ 7.2 Hz, 2H, ArH), 3.04 (q,
J ¼ 7.2 Hz, 6H, CH2), 1.16 (t, J ¼ 7.2 Hz, 9H, CH3). 13C NMR (150 MHz, DMSO-
d6) d: 163.4, 162.1, 136.2, 129.2, 128.2, 127.7, 118.6, 81.8, 45.8, 8.6. MS (m=z):
236.72 ([M-C6H16N]þ) 100%.
Compound 2p. Mp: >250 ꢀC. IR (KBr) t: 3112, 2988, 2789, 2723, 2209,
1
1626, 1514, 1423, 1395, 1244, 1222, 1181, 1095, 1038, 1017, 886, 832, 778 cmꢁ1. H
NMR (600 MHz, DMSO-d6) d: 7.56 (d, J ¼ 8.4 Hz, 2H, ArH), 7.43 (d, J ¼ 8.4 Hz,
2H, ArH), 3.05 (q, J ¼ 7.2 Hz, 6H, CH2), 1.16 (t, J ¼ 7.2 Hz, 9H, CH3). 13C NMR

1422
Y. HAN ET AL.
(150 MHz, DMSO-d6) d: 163.2, 106.8, 135.1, 134.0, 129.7, 128.4, 118.5, 81.7, 45.8,
8.7. MS (m=z): 270.88 ([M-C6H16N]þ) 100%.
Compound 2q. Mp: >250 ꢀC. IR (KBr) t: 3477, 3109, 2987, 2789, 2208,
1627, 1514, 1472, 1395, 1221, 1181, 1072, 1037, 1013, 884, 829, 778 cmꢁ1 1H
.
NMR (600 MHz, DMSO-d6) d: 7.69 (d, J ¼ 7.8 Hz, 2H, ArH), 7.36 (d, J ¼ 7.8 Hz,
2H, ArH), 2.59 (q, J ¼ 7.2 Hz, 6H, CH2), 1.12 (t, J ¼ 7.2 Hz, 9H, CH3). 13C NMR
(150 MHz, DMSO-d6) d: 163.2, 160.8, 135.5, 131.3, 130.0, 122.6, 118.5, 81.6, 45.7,
8.8. MS (m=z): 315.24 ([M-C6H16N]þ) 100%.
Compound 2r. Mp: >250 ꢀC. IR (KBr) t: 3109, 2960, 2808, 2202, 1620, 1508,
1474, 1417, 1321, 1223, 1162, 1053, 895, 836, 782 cmꢁ1. 1H NMR (600 MHz, DMSO-
d6) d: 10.58 (s, 1H, NH), 7.49 (d, J ¼ 8.4 Hz, 2H, ArH), 7.34 (d, J ¼ 7.8 Hz, 2H, ArH),
3.03 (s, 12H, CH2), 1.32 (s, 9H, CH3). 13C NMR (150 MHz, DMSO-d6) d: 163.5,
161.7, 151.6, 133.3, 127.7, 124.9, 119.0, 81.5, 44.1, 34.5, 31.0. MS (m=z): 292.54
([M-C6H13N2]þ) 100%.
Compound 2s. Mp: >250 ꢀC. IR (KBr) t: 3086, 2954, 2804, 2213, 1618, 1511,
1473, 1406, 1321, 1241, 1222, 1092, 1053, 1018, 900, 836, 779 cmꢁ1 1H NMR
.
(600 MHz, DMSO-d6) d: 7.56 (d, J ¼ 7.2 Hz, 2H, ArH), 7.44 (d, J ¼ 7.8 Hz, 2H,
ArH), 3.04 (s, 12H, CH2). 13C NMR (150 MHz, DMSO-d6) d: 163.3, 160.9, 135.1,
134.0, 129.7, 128.4, 118.5, 81.7, 43.9. MS (m=z): 271.33 ([M-C6H13N2]þ) 100%.
Compound 2t. Mp: >250 ꢀC. IR (KBr) t: 3083, 2953, 2798, 2212, 1618, 1511,
1473, 1407, 1320, 1240, 1052, 1012, 885, 833, 778 cmꢁ1; 1H NMR (600 MHz, DMSO-
d6) d: 7.69 (d, J ¼ 7.8 Hz, 2H, ArH), 7.37 (d, J ¼ 8.4 Hz, 2H, ArH), 3.04 (s, 12H,
CH2). 13C NMR (150 MHz, DMSO-d6) d: 163.2, 160.9, 135.5, 131.3, 130.0, 122.7,
118.5, 81.7, 43.9. MS (m=z): 315.15 ([M- C6H13N2]þ) 100%.
Compound 2r. Mp: >250 ꢀC; IR (KBr) t: 3393, 3113, 2870, 2809, 2205, 1636,
1545, 1514, 1467, 1420, 1351, 1249, 1221, 1154, 1087, 1008, 933, 883, 846, 804 cmꢁ1
;
1H NMR (600 MHz, DMSO-d6) d: 10.75 (brs, 1H, NH), 8.34 (d, J ¼ 6.6 Hz, 1H,
ArH), 8.26 (s, 1H, ArH), 7.91 (d, J ¼ 7.2 Hz, 1H, ArH), 7.81 (t, J ¼ 7.8 Hz, 1H,
ArH), 3.04 (s, 12H, CH2);13C NMR (150 MHz, DMSO-d6) d: 163.2, 159.4, 147.4,
137.8, 134.7, 130.2, 124.1, 122.7, 118.4, 81.7, 44.0; MS (m=z): 281.40 ([M-C6H13N2]þ)
100%.
SUPPORTING INFORMATION
Crystallographic data (1a: CCDC 753685; 2e: CCDC 771090; 2 h: CCDC
771092; 2 t: CCDC 771091) have been deposited at the Cambridge Crystallographic
Database Centre.
ACKNOWLEDGMENTS
This work was financially supported by the National Natural Science Foun-
dation of China (Grant No. 20972132) and the Key Laboratory of Environmental
Resource and Material, Jiangsu Province.

AMMONIUM 3,5-DICYANO-4-ARYL-2,6-PYRIDINEDIONATES
1423
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