Synthesis and Antifungal Activity Evaluation of Novel Substituted Pyrimidine-5-Carboxamides Bearing the Pyridine Moiety

Article abstract of DOI:10.1002/jccs.201700310

A series of novel N-(substituted phenyl/benzyl)-2-methylthio-4-((pyridin-3-ylmethyl)amino)pyrimidine-5-carboxamides were synthesized by multistep reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR, and elemental analysis. Their in vitro antifungal activities against two kinds of plant pathogenic fungi were evaluated by the mycelial growth rate method. The result showed that at the dosage of 100 μg/mL, several of these compounds exhibited moderate activity against Botrytis cinerea with inhibition rates of ~70%, and most compounds (e.g., 5a, 5c, 5e, 5f, and 5h) possessed excellent activity against Sclerotinia Sclerotiorum with more than 90% inhibition rate.

Full text of DOI:10.1002/jccs.201700310

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Article
Synthesis and Antifungal Activity Evaluation of Novel Substituted Pyrimidine-
5-Carboxamides Bearing the Pyridine Moiety
*
Shi-Chun Wang, Fu-Xian Wan, Si Liu, Shuai Zhang and Lin Jiang
College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, 271018, China
(Received: September 7, 2017; Accepted: November 13, 2017; DOI: 10.1002/jccs.201700310)
A series of novel N-(substituted phenyl/benzyl)-2-methylthio-4-((pyridin-3-ylmethyl)amino)pyrimi-
dine-5-carboxamides were synthesized by multistep reactions. The structures of the target com-
1
pounds were characterized by IR, H NMR, 13C NMR, and elemental analysis. Their in vitro
antifungal activities against two kinds of plant pathogenic fungi were evaluated by the mycelial
growth rate method. The result showed that at the dosage of 100 μg/mL, several of these com-
pounds exhibited moderate activity against Botrytis cinerea with inhibition rates of ~70%, and
most compounds (e.g., 5a, 5c, 5e, 5f, and 5h) possessed excellent activity against Sclerotinia Sclero-
tiorum with more than 90% inhibition rate.
Keywords: Pyrimidine; Pyridine; Carboxamide; Synthesis; Antifungal activity.
INTRODUCTION
Botrytis cinerea and Sclerotinia sclerotiorum are
addition, among the pyrimidine derivatives, pyrimidine-
carboxamides represent a promising class of bioactive sub-
stances and have received much attention in the field of
medicine. For example, 2-thioxo-1,2-dihydro pyrimidine-
5-carboxamides (I) have moderate antibacterial activity
against Bacillus subtilis11; N-(piperidin-3-yl) pyrimidine-
5-carboxamides (II) can be used as renin inhibitor12; 1,2-
dihydropyrimidine-5-carboxamide containing morpho-
line moiety (III) exhibits good antihypertensive activity13;
and di-substituted amino pyrimidine-5-carboxamides
(IV) synthesized by Liang behave as excellent BMX
kinase inhibitors.14 Their structures are shown in
Figure 1. However, this series of compounds have rarely
been studied in the form of pesticides.
two critical plant pathogenic fungi infecting many eco-
nomic crops such as fruits and vegetables. The diseases
caused by the two fungi can seriously affect the yields
of crops: for example, B. cinerea reduces tomato yield
by 30–50%,1 and S. sclerotiorum reduces rape yield by
20–40%.2 The main method to control such diseases is
by employing chemical fungicides such as carbendazim,
boscalid, prochloraz, and so on. In recent years, how-
ever, the wide and indiscriminate use of fungicides has
led to the development of serious resistance.3 Therefore,
there is an urgent need to develop new and effective
antifungal agents with novel structures.
Pyrimidine is an important six-membered heterocyclic
nucleus containing two nitrogen atoms. The diversity of the
types and positions at pyrimidine ring results in an abun-
dance of its derivatives. A literature survey shows that
pyrimidine derivatives possess a broad spectrum of biologi-
cal properties, such as antifungal,4 antibacterial,5
anticancer,6 anti-inflammatory,7 antidiabetic,8 insecticidal,9
and herbicidal10 activities. Many pyrimidine-based com-
pounds play important roles in the field of pesticide due to
their high activity, low toxicity, and unique action mecha-
nism. For example, mepanipyrim, cyprodinil, diflumetorim,
and azoxystrobin are all excellent agricultural fungicides. In
On the other hand, pyridine is a significant
nitrogen-containing heterocyclic compound, and its
derivatives also show a wide spectrum of biological
properties, including antifungal,15 antimicrobial,16
antitumor,17 antiviral,18 herbicidal,19 and insecticidal20
activities. Many pyridine derivatives play crucial roles
as agrochemicals due to their high activity, low toxicity,
and excellent selectivity. The well-known fungicides
boscalid, fluopicolide, and pyribencarb are examples of
pyridine derivatives.21
In view of the above-mentioned findings, in this
study we have linked the (pyridin-3-ylmethyl)amino
*Corresponding author. Email: jiangl@sdau.edu.cn
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1

Article
Wang et al.
CH2 attached to the pyridine ring at 41.1–42.0 ppm.
The signals of carbaxamide carbon were observed at
172.9–175.0 ppm. The signals at 103.7–166.7 ppm were
assigned to the aromatic carbons. In their IR spectra,
the broad bands at 3225–3276 cm−1 were assigned to
the N–H stretching vibration, and those at
1633–1660 cm−1 were attributed to the C=O of carbax-
amide group. The weak or moderate bands of the C–S–
C bond could be observed at 710–715 cm−1
.
Antifungal activity
The in vivo antifungal activities of the target com-
pounds against B. cinerea and S. Sclerotiorum are listed
in Table 1. As can be seen from the table, some target
compounds exhibit moderate antifungal activities
against B. cinerea at 50 μg/mL with inhibition rates of
60.6–67.3%. Some compounds such as 5a, 5b, 5e, 5g,
and 5f show notable activity with more than 70% inhi-
bition rates at 100 μg/mL but they are lower than that
of chlorothalonil (inhibition rate, 87.3%). On the other
hand, many compounds show inhibition rates of
61.0–74.8% against S. Sclerotiorum at 50 μg/mL, sug-
gesting that they have moderate antifungal activities;
except 5b, 5g, and 5i, the other 10 compounds display
excellent antifungal activities with more than 90% inhi-
bition rates at 100 μg/mL, and their activities are higher
than that of chlorothalonil (inhibition rate, 87.6%). In
general, the target compounds possess better inhibition
efficacy toward S. Sclerotiorum than toward B. cinerea.
From Table 1, it is also seen that the two kinds of syn-
thesized compounds (5a–5i) and their N-(substituted
benzyl)analogs (5j–5m) showed no obvious difference in
their antifungal activity.
Fig.
1. Structures
of
some
pyrimidine-5-
carboxamides.
moiety to the pyrimidine ring bearing a carboxamide
group. Thus, we have designed and synthesized a series
of novel pyrimidine-5-carboxamides containing the pyr-
idine moiety and evaluated their antifungal activity
against B. cinerea and S. sclerotiorum.
RESULTS AND DISCUSSION
Chemistry
The synthesis of the target compounds 5a–5m is out-
lined in Scheme 1. Ethyl 4-hydroxy-2-(methylthio)
pyrimidine-5-carboxylate (1) was prepared by the reaction
of diethyl ethoxymethylenemalonate with S-methyl iso-
thiourea sulfate in the presence of NaOH,22 followed by
halogenation with POCl3 to convert to its 4-chloro deriv-
ative (2).14 Subsequently, 2 was reacted with 3-picolyl
amine to yield the key intermediate ethyl 2-methyl thio-4-
((pyridin-3-ylmethyl)amino)pyrimidine-5-carboxylate (3),
which was then hydrolyzed and acidified to give the
substituted pyrimidine-5-carboxylic acid (4). Finally,
4 was reacted with different substituent amines or benzyl-
amines to afford the target compounds 5.23
The structures of the target compounds were con-
firmed by 1H NMR, 13C NMR, IR, and elemental
1
analysis. In the HNMR spectra, the singlet signals at
2.43–2.54 ppm were assigned to SCH3 protons, and the
signals at 4.73–4.77 ppm were due to the CH2 protons
attached to pyridine ring. The chemical shifts at
7.65–7.73 ppm were attributed to the proton of the
pyrimidine ring. The broad signals of the NH protons
on the pyrimidine ring were observed at 9.03–9.23 ppm.
In the 13C NMR spectra, the chemical shifts of the
SCH3 carbon appeared at 13.4–14.2 ppm and those of
Scheme 1. Synthetic route of the title compound 5.
2
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Antifungal Activity of Pyrimidine-5-carboxamides
Table 1. Antifungal activity as inhibition rate for the target compounds 5a–5m (%)
B. cinerea
S. sclerotiorum
Compd.
R
n
50 ub
100 u
50 u
100 u
5a
5b
5c
5d
5e
5f
5g
5h
5i
H
0
0
0
0
0
0
0
0
0
1
1
1
1
61.2
67.3
51.5
60.6
65.0
57.6
62.6
56.5
58.7
49.6
54.8
61.9
50.3
82.7
70.5
73.0
64.2
70.4
71.6
66.5
71.2
71.1
67.5
69.6
68.3
68.5
68.7
87.3
66.7
57.8
67.0
58.3
74.8
56.9
57.4
61.9
53.9
67.4
64.8
56.1
61.0
79.3
96.2
80.5
96.6
93.2
95.2
96.1
86.6
96.7
79.5
90.0
93.1
96.7
93.1
87.6
4-CH3
4-CH(CH3)2
4-CH3O
4-F
3-Cl
4-Cl
4-Br
2-OH-5-Cl
H
4-CH3O
4-F
4-Cl
5j
5k
5l
5m
CKa
a CK, the control, chlorothalonil.
b u, unit of the tested concentration (μg/mL).
CONCLUSIONS
Synthesis of ethyl 2-(methylthio)-4-((pyridin-3-ylmethyl)
amino)pyrimidine-5-carboxylate (3)
In summary, 13 novel N-(substituted phenyl)-2-
methylthio-4-((pyridin-3-ylmethyl)amino)pyrimidine-5-
carboxamides and their N-(substituted benzyl) analogs
were synthesized from diethyl ethoxymethylene-malo-
nate, S-methylisothiourea sulfate, 3-picolylamine, and
the substituent amines as starting materials. In vitro
bioassay showed that most target compounds (e.g. 5a,
5c, 5e, 5f, and 5h) exhibited excellent antifungal activi-
ties against S. sclerotiorum at 100 μg/mL. This study
provides a useful reference in the search for novel
pyrimidine-based antifungal agents.
3-Picolylamine 1.08 g (10 mmol) was added to a
mixture of 1.86 g (8 mmol) ethyl 4-chloro-2-
(methylthio) pyrimidine-5-carboxylate in dioxane
(20 mL). The reaction mixture was refluxed for 2 h,
and then concentrated under reduced pressure. The resi-
due was purified by silica gel chromatography with
petroleum ether/acetone (4:1 v/v) as eluent to give com-
pound 3. Yield 91%, white solid, m.p. 166–167ꢀC; IR
(KBr) ν cm−1: 3354 (NH), 1681 (C=O), 1572, 1484
1
(C=C), 714 (C–S–C); H NMR (400 MHz, CDCl3) δ
(ppm): 8.67 (s, 2H, Pyrim-NH + Py-H), 8.61 (s, 1H,
Py-H), 8.53 (d, 1H, J = 4.0 Hz, Py-H), 7.65 (d, 1H,
J = 7.6 Hz, Pyrim-H), 7.26 (t, 1H, J = 5.6 Hz, Py-H),
4.78 (d, 2H, J = 5.6 Hz, Py-CH2), 4.32 (q, 2H,
J = 7.2 Hz, OCH2CH3), 2.46 (s, 3H, SCH3), 1.37 (t,
3H, J = 7.2 Hz, OCH2CH3); Anal. Calc. for
C14H16N4O2S: C, 55.25; H, 5.30; N, 18.41%; Found: C,
55.42; H, 5.49; N, 18.20%.
EXPERIMENTAL
General
Melting points were determined using a Beijing
Tech X-5 microscope melting point apparatus and are
uncorrected. IR spectra were recorded on a Shimadzu
1
IR-440 infrared spectrophotometer using KBr disks. H
NMR and 13C NMR spectra were recorded on a Bru-
ker AM-400 spectrometer using TMS as internal stan-
dard (1H NMR at 400 MHz, 13C NMR at 100 MHz).
Elemental analyses were carried out on an Elementary
Vario EL III analyzer.
Synthesis of 2-(methylthio)-4-((pyridin-3-ylmethyl)amino)
pyrimidine-5-carboxylic acid (4)
The substituted pyrimidine-5-carboxylate (3)
3.04 g (10 mmol) in 1 mol/L NaOH solution (30 mL)
was refluxed for 20 min. The reaction solution was then
adjusted to pH ~ 5 with dilute hydrochloric acid,
All reagents were obtained from commercial
sources and used without further purification.
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
3

Article
Wang et al.
whereupon a large amount of solid precipitated. The
precipitate was filtered off, washed with water, and
dried to afford 4. Yield 81%, pale yellow solid,
m.p. 222–223ꢀC; IR (KBr) ν cm−1: 3322 (NH), 1680
(C=O), 1573, 1475 (C=C), 707 (C–S–C); 1H NMR
(400 MHz, CDCl3) δ (ppm): 8.95 (brs, 1H, Pyrim-NH),
8.57 (s, 1H, Py-H), 8.54 (s, 1H, Py-H), 8.45 (d, 1H,
J = 3.2 Hz, Py-H), 7.72 (d, 1H, J = 7.6 Hz, Pyrim-H),
7.24 (q, 1H, J = 2.4 Hz, Py-H), 4.76 (d, 2H,
J = 6.0 Hz, Py-CH2), 2.40 (s, 3H, SCH3); Anal. Calc.
for C12H12N4O2S: C, 52.16; H, 4.38; N, 20.28%;
found C, 52.13; H, 4.60; N, 20.27%.
1H, Pyrim-NH), 8.61 (s, 1H, Py-H), 8.51 (d, 1H,
J = 4.0 Hz, Py-H), 8.39 (s, 1H, Py-H), 7.89 (brs, 1H, –
C(=O)–NH), 7.66 (d, 1H, J = 8.0 Hz, Pyrim-H),
7.16–7.38 (m, 5H, Py-H + Ph-H), 4.75 (d, 2H,
J = 5.6 Hz, Py-CH2), 2.47 (s, 3H, SCH3), 2.33 (s, 3H,
Ph–CH3); 13C NMR (100 MHz, CDCl3) δ (ppm):
175.0, 165.4, 160.1, 153.7, 149.2, 148.7, 135.2, 134.9,
134.4, 134.0, 129.6, 123.6, 121.3, 104.4, 42.0, 20.9,
14.2; Anal. Calc. for C19H19N5OS: C, 62.45; H,
5.24; N, 19.16%; found: C, 62.68; H, 5.54; N, 18.88%.
N-(4-Isopropylphenyl)-2-methylthio-4-((pyridin-3-
yl methyl)amino)pyrimidine-5-carboxamide (5c): Yield
66%, white solid, m.p. 201–202ꢀC; IR (KBr) ν cm−1
:
General procedure for synthesis of N-(substituented
phenyl/benzyl-4-((pyridin-3-ylmethyl)amino)pyrimidine-
5-carboxamides (5)
3254 (NH), 1643 (C=O), 1574, 1493 (C=C), 714 (C–S–
C); 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.08
(brs, 1H, –C(=O)–NH), 9.19 (t, 1H, J = 6 Hz, Pyrim-
NH), 8.67 (s, 1H, Py–H), 8.59 (s, 1H, Py–H), 8.45 (d,
1H, J = 3.6 Hz, Py–H), 7.73 (d, 1H, J = 8.0 Hz,
Pyrim-H), 7.16–7.59 (m, 5H, Py-H + Ph-H), 4.73 (d,
2H, J = 6.0 Hz, Py-CH2), 2.87 (m, 1H, CH), 2.53 (s,
3H, SCH3), 1.22 (d, 6H, J = 6.8 Hz, –CH(CH3)2); 13C
NMR (100 MHz, CDCl3) δ (ppm): 174.7, 165.5, 160.2,
153.9, 149.1, 148.7, 145.7, 135.3, 135.0, 134.1, 126.9,
123.6, 121.4, 104.4, 42.0, 33.6, 24.0, 14.1; Anal. Calc.
for C21H23N5OS: C, 64.10; H, 5.89; N, 17.80%;
found: C, 64.42; H, 6.11; N, 17.52%.
N-(4-Methoxyphenyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)pyrimidine-5-carboxamide (5d): Yield
65%, white solid, m.p. 187–188ꢀC; IR (KBr) ν cm−1:
3275 (NH), 1640 (C=O), 1575, 1510 (C=C), 712 (C–S–
C); 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.04
(brs, 1H, –C(=O)–NH), 9.21 (t, 1H, J = 6.0 Hz, Pyrim–
NH), 8.66 (s, 1H, Py–H), 8.58 (s, 1H, Py–H), 8.45 (d,
J = 6.0 Hz, 1H, Py–H), 7.73 (d, 1H, J = 8.0 Hz, Pyrim–
H), 6.85–7.56 (m, 5H, Py–H + Ph–H), 4.73 (d, 2H,
J = 6.0 Hz, Py–CH2), 3.77 (s, 3H, OCH3), 2.54 (s, 3H,
SCH3); 13C NMR (100 MHz, CDCl3) δ (ppm): 173.0,
164.7, 159.4, 155.6, 154.6, 148.7, 147.8, 134.8, 134.3,
131.1, 123.1, 122.3, 113.2, 104.5, 54.8, 41.1, 13.5; Anal.
Calc. for C19H19N5O2S: C, 59.83; H, 5.02; N, 18.36%;
found: C, 59.87; H, 5.31; N, 18.25%.
The appropriate aniline/benzylamine (10 mmol)
was added slowly to
a mixture of substituted
pyrimidine-5-carboxylic acid (4) 2.76 g (10 mmol),
DCC 2.16 g (10.5 mmol), and DMAP 0.06 g
(0.5 mmol) in dry dichloromethane (30 mL) and stirred
overnight at room temperature. The progress of the
reaction was monitored by TLC with petroleum ether/
acetone (2:1, v/v) as a developing solvent. When the
reaction was completed, the reaction mixture was fil-
tered off, and the filtrate was evaporated in vacuum.
The crude product was recrystallized from DMF–H2O
to afford target compounds 5a–5m.
N-Phenyl-2-methylthio-4-((pyridin-3-ylmethyl)amino)
pyrimidine-5-carboxamide (5a): Yield 65%, white solid,
m.p. 184–185ꢀC; IR (KBr) ν cm−1: 3271 (NH), 1649
(C=O), 1575, 1489 (C=C), 712 (C–S–C); 1H NMR
(400 MHz, CDCl3) δ (ppm): 9.07 (brs, 1H, Pyrim-NH),
8.61 (s, 1H, Py-H), 8.52 (d, 1H, J = 4.4 Hz, Py-H), 8.41
(s, 1H, Py-H), 7.80 (brs, 1H, –C(=O)–NH), 7.65 (d, 1H,
J = 8.0 Hz, Pyrim-H), 7.16–7.51 (m, 6H, Py-H + Ph-H),
4.76 (d, 2H, J = 6.0 Hz, Py-CH2), 2.47 (s, 3H, SCH3); 13
C
NMR (100 MHz, CDCl3) δ (ppm): 174.9, 165.5, 160.1,
154.0, 149.1, 148.7, 137.4, 135.3, 134.1, 129.0, 124.9,
123.7, 121.2, 104.3, 42.0, 14.2; Anal. Calc. for
C18H17N5OS: C, 61.52; H, 4.88; N, 19.93%; found: C,
61.57; H, 5.16; N, 19.74%.
N-(4-Fluorophenyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)pyrimidine-5-carboxamide (5e): Yield
N-(4-Methylphenyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)-pyrimidine-5-carboxamide (5b): Yield
65%, white solid, m.p. 230–231ꢀC; IR (KBr) ν cm−1
:
70%, white solid, m.p. 226–228ꢀC; IR (KBr) ν cm−1
:
3248 (NH), 1654 (C=O), 1578, 1492 (C=C),
1
3251 (NH), 1645 (C=O), 1574, 1493 (C=C), 715 (C–S–
716 (C–S–C); H NMR (400 MHz, CDCl3) δ (ppm):
1
C); H NMR (400 MHz, CDCl3) δ (ppm): 9.08 (brs,
9.05 (brs, 1H, Pyrim-NH), 8.62 (s, 1H, Py-H), 8.53
4
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Antifungal Activity of Pyrimidine-5-carboxamides
(d, 1H, J = 3.2 Hz, Py-H), 8.39 (s, 1H, Py-H), 7.67
(brs, 1H, –C(=O)–NH), 7.65 (s, 1H, Pyrim-H),
7.05–7.48 (m, 5H, Py-H + Ph-H), 4.76 (d, 2H,
J = 6.0 Hz, Py-CH2), 2.48 (s, 3H, SCH3); 13C NMR
(100 MHz, CDCl3) δ (ppm): 173.2, 164.9, 159.3,
157.1, 154.9, 148.8, 147.9, 134.6, 134.4, 123.2, 122.4,
122.3, 114.9, 114.7, 104.5, 41.2, 13.5; Anal. Calc. for
C18H16FN5OS: C, 58.82; H, 4.37; N, 18.96%;
found: C, 58.42; H, 4.67; N, 18.74%.
J = 8.0 Hz, Pyrim-H), 7.29–7.67 (m, 5H, Py-H + Ph-
H), 4.74 (d, 2H, J = 5.6 Hz, Py-CH2), 2.43 (s, 3H,
SCH3); 13C NMR (100 MHz, CDCl3 + DMSO-d6) δ
(ppm): 173.4, 165.1, 159.3, 154.9, 148.7, 147.9, 137.6,
134.8, 134.2, 130.9, 123.0, 122.2, 115.6, 104.2, 41.2,
13.5; Anal. Calc. for C18H16BrN5OS: C, 50.24; H,
3.75; N, 16.27%; found: C, 49.92; H, 3.88; N, 15.95%.
N-(5-Chloro-2-hydroxyphenyl)-2-methylthio-4-((pyr-
idin-3-ylmethyl)amino)pyrimidine-5-carboxamide (5i):
Yield 79%, white solid, m.p. 239–240ꢀC; IR (KBr) ν
cm−1: 3276 (NH), 1649 (C=O), 1575, 1492 (C=C),
710 (C–S–C); 1H NMR (400 MHz, DMSO-d6) δ (ppm):
9.84 (brs, 1H, OH), 9.48 (brs, 1H, –C(=O)–NH), 9.19
(brs, 1H, Pyrim-NH), 8.65 (s, 1H, Py-H), 8.58 (s, 1H,
Py-H), 8.45 (s, J = 4.0 Hz, 1H, Py-H), 6.88–7.74 (m,
5H, Py-H + Pyrim-H + Ph-H), 4.74 (s, 2H, Py-CH2),
2.43 (s, 3H, SCH3); 13C NMR (100 MHz, CDCl3 +
DMSO-d6) δ (ppm): 173.3, 165.0, 159.3, 155.0, 148.8,
148.2, 147.9, 134.9, 134.5, 126.2, 124.9, 123.8, 123.2,
122.2, 116.6, 104.2, 41.2, 13.5; Anal. Calc. for
C18H16ClN5O2S: C, 53.80; H, 4.01; N, 17.43%;
found: C, 53.62; H, 4.24; N, 17.18%.
N-Benzyl-2-methylthio-4-((pyridin-3-ylmethyl)amino)
pyrimidine-5-carboxamide (5j): Yeild 59%, white solid,
m.p. 152–153ꢀC; IR (KBr) ν cm−1: 3228 (NH), 1634
(C=O), 1577, 1494 (C=C), 710 (C–S–C); 1H NMR
(400 MHz, CDCl3) δ (ppm): 9.22 (brs, 1H, Pyrim-NH),
8.60 (s, 1H, Py-H), 8.51 (d, 1H, J = 3.6 Hz, Py-H), 8.22
(s, 1H, Py-H), 7.66 (d, 1H, J = 8.0 Hz, Pyrim-H),
7.24–7.37 (m, 6H, Py-H + Ph-H), 6.55 (brs, 1H, –C(=O)–
NH), 4.74 (d, 2H, J = 6.0 Hz, Py-CH2), 4.57 (d,
J = 5.6 Hz, 2H, Ph-CH2), 2.44 (s, 3H, SCH3); 13C NMR
(100 MHz, CDCl3) δ (ppm): 174.2, 166.8, 160.0, 153.7,
148.9, 148.4, 138.0, 135.1, 134.2, 128.5, 127.6, 127.4,
123.5, 103.8, 43.4, 41.7, 14.1; Anal. Calc. for
C19H19N5OS: C, 62.45; H, 5.24%; N, 19.16; found: C,
62.28; H, 5.57; N, 18.88%.
N-(3-Chlorophenyl)-2-methylthio-4-((pyridin-3-yl
methyl) amino)pyrimidine-5-carboxamide (5f): Yield
62%, white solid, m.p. 175–176ꢀC; IR (KBr) ν cm−1
:
3250 (NH), 1660 (C=O), 1576, 1479 (C=C), 717 (C–S–
1
C); H NMR (400 MHz, CDCl3) δ (ppm): 9.04 (brs,
1H, Pyrim-NH), 8.62 (s, 1H, Py-H), 8.53 (d, 1H,
J = 4.0 Hz, Py-H), 8.40 (s, 1H, Py-H), 7.80 (brs, 1H, –
C(=O)–NH), 7.67 (s, 1H, Pyrim-H), 7.14–7.65 (m, 5H,
Py-H + Ph-H), 4.77 (d, 2H, J = 6.0 Hz, Py-CH2),
2.48 (s, 3H, SCH3); 13C NMR (100 MHz, CDCl3) δ
(ppm): 175.1, 165.4, 160.1, 153.9, 149.1, 148.8, 138.7,
135.3, 134.6, 133.9, 129.9, 124.8, 123.7, 121.0, 118.8,
103.9, 42.1, 14.2; Anal. Calc. for C18H16ClN5OS: C,
56.03; H, 4.18; N, 18.15%; found: C, 55.61; H,
4.47; N, 17.89%.
N-(4-Chlorophenyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)pyrimidine-5-carboxamide (5g): Yield
68%, white solid, m.p. 245–246ꢀC; IR (KBr) ν cm−1
:
3263 (NH), 1655 (C=O), 1575, 1494 (C=C), 716 (C–S–
1
C); H NMR (400 MHz, CDCl3) δ (ppm): 9.03 (brs,
1H, Pyrim-NH), 8.62 (s, 1H, Py-H), 8.53 (d,
J = 4.8 Hz, 1H, Py-H), 8.39 (s, 1H, Py-H), 7.72 (brs,
1H, –C(=O)–NH), 7.66 (d, 1H, J = 8.0 Hz, Pyrim-H),
7.26–7.48 (m, 5H, Py-H + Ph-H), 4.77 (d, 2H,
J = 6.0 Hz, Py-CH2), 2.48 (s, 3H, SCH3); 13C NMR
(100 MHz, CDCl3 + DMSO-d6) δ (ppm): 173.3, 165.0,
159.3, 155.0, 148.7, 147.9, 137.2, 134.9, 134.4, 128.1,
127.6, 123.1, 121.9, 104.4, 41.2, 13.5; Anal. Calc. for
C18H16ClN5OS: C, 56.03; H, 4.18; N, 18.15%;
found: C, 55.01; H, 4.41; N, 18.00%.
N-(4-Methoxybenzyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)pyrimidine-5-carboxamide (5k): Yield
57%, white solid, m.p. 188–189ꢀC; IR (KBr) ν cm−1:
3234 (NH), 1633 (C=O), 1579, 1494 (C=C), 710 (C–S–
C); 1H NMR (400 MHz, CDCl3) δ (ppm): 9.23 (brs,
1H, Pyrim-NH), 8.59 (s, 1H, Py-H), 8.50 (d, J = 3.6 Hz,
1H, Py-H), 8.21 (s, 1H, Py-H), 7.66 (d, 1H, J = 8.0 Hz,
Pyrim-H), 6.86–7.26 (m, 5H, Py-H + Ph-H), 6.54 (brs,
1H, –C(=O)–NH), 4.74 (d, 2H, J = 5.6 Hz, Py-CH2),
4.57 (d, J = 6.0 Hz, 2H, Ph-CH2), 3.80 (s, 3H, Ph-CH3),
N-(4-Bromophenyl)-2-methylthio-4-((pyridin-3-yl
methyl)amino)pyrimidine-5-carboxamide (5h): Yield
67%, white solid, m.p. 245–246ꢀC; IR (KBr) ν cm−1
:
3266 (NH), 1655 (C=O), 1574, 1489 (C=C), 715 (C–
S–C); 1H NMR (400 MHz, CDCl3) δ (ppm): 10.23
(brs, 1H, –C(=O)–NH), 9.14 (t, 1H, J = 6.0 Hz,
Pyrim-NH), 8.67 (s, 1H, Py-H), 8.58 (s, 1H, Py-H),
8.45 (s, 1H, J = 4.8 Hz, Py-H), 7.73 (d, 1H,
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
5

Article
Wang et al.
2.43 (s, 3H, SCH3); 13C NMR (100 MHz, CDCl3) δ
(ppm): 174.6, 166.7, 160.1, 159.1, 153.5, 149.1, 148.6,
135.2, 134.2, 129.8, 129.2, 123.5, 114.1, 103.9, 55.3, 43.2,
41.9, 14.2; Anal. Calc. for C20H21N5O2S: C, 60.74; H,
5.35; N, 17.71%; found: C, 60.39; H, 5.69; N, 17.50%.
N-(4-Fluorobenzyl)-2-methylthio-4-((pyridin-3-
ylmethyl) amino)pyrimidine-5-carboxamide (5l):
Yield 52%, white solid, m.p. 196–197ꢀC; IR (KBr) ν
cm−1: 3232 (NH), 1635 (C=O), 1578, 1495 (C=C),
Three replicates were performed in the bioassay. The
inhibition rate was calculated by the following formula:
Inhibition rate ð%Þ = ½ðD0 – D1Þ=D0ꢁ × 100
where D0 is the expansion diameter of the mycelia in
the blank test, and D1 is the expansion diameter of
mycelia in the presence of the tested compound.
1
710 (C–S–C); H NMR (400 MHz, CDCl3) δ (ppm):
ACKNOWLEDGMENT
9.19 (brs, 1H, Pyrim-NH), 8.61 (s, 1H, Py-H), 8.52
(d, 1H, J = 4.0 Hz, Py-H), 8.22 (s, 1H, Py-H), 7.66
(d, 1H, J = 8.0 Hz, Pyrim-H), 7.02–7.30 (m, 5H,
Py-H + Ph-H), 6.40 (brs, 1H, –C(=O)–NH), 4.75 (d,
2H, J = 6.0 Hz, Py-CH2), 4.54 (d, 2H, J = 6.0 Hz,
Ph-CH2), 2.44 (s, 3H, SCH3); 13C NMR (100 MHz,
CDCl3) δ (ppm): 172.9, 166.2, 162.3, 159.9, 159.5,
154.3, 148.6, 147.8, 134.8, 134.3, 128.9, 123.1,
114.7, 103.7, 41.6, 41.1, 13.4; Anal. Calc. for
C19H18FN5OS: C, 59.52; H, 4.73; N, 18.26%;
found: C, 58.96; H, 5.04; N, 17.96%.
This work was supported by the Natural Science
Foundation of Shandong Province, China (No.
ZR2014BM030).
SUPPORTING INFORMATION
Additional supporting information is available in
the online version of this article.
REFERENCES
1. C. Y. Zhang, Z. X. Zhang, G. R. Cui, Plant Protection
2006, 32, 32.
N-(4-Chlorobenzyl)-2-methylthio-4-((pyridin-3-
2. H. Hu, Q. Dong, J. Wu, D. Huo, Y. Wang, H. Yang, J.
Anhui Agri. Sci. 2013, 41, 5283.
ylmethyl)amino)pyrimidine-5-carboxamide
(5m):
Yield 53%, white solid, m.p. 189–190ꢀC; IR (KBr) ν
3. G.
A.
Bardas,
T.
Veloukas,
O.
Koutita,
cm−1: 3225 (NH), 1635 (C=O), 1580, 1493 (C=C),
G. S. Karaoglanidis, Pest Manag. Sci. 2010, 66, 967.
4. D. M. Neumann, A. Cammarata, G. Backes, G. E. Palmer,
B. S. Jursic, Bioorg. Med. Chem. 2014, 22, 813.
5. Y. P. Yi, X. M. Xu, Y. Liu, S. J. Xu, X. Huang,
J. P. Liang, R. F. Shang, Eur. J. Med. Chem. 2017,
126, 687.
6. A. A. Abu-Hashem, F. A. Badria, J. Chin. Chem. Soc.
2015, 62, 506.
7. A. Orjales, R. Mosquera, B. Lopez, R. Olivera,
R. L. Labeaga, M. T. Nunez, Bioorg. Med. Chem. 2008,
16, 2183.
1
710 (C–S–C); H NMR (400 MHz, CDCl3) δ (ppm):
9.19 (brs, 1H, Pyrim-NH), 8.60 (s, 1H, Py-H), 8.51
(d, 1H, J = 4.0 Hz, Py-H), 8.24 (s, 1H, Py-H), 7.65
(d, 1H, J = 8.0 Hz, Pyrim-H), 7.24–7. 33 (m, 5H,
Py-H + Ph-H), 6.58 (brs, 1H, –C(=O)–NH), 4.74 (d,
2H, J = 5.6 Hz, Py-CH2), 4.54 (d, 2H, J = 5.6 Hz,
Ph-CH2), 2.44 (s, 3H, SCH3); 13C NMR (100 MHz,
CDCl3 + DMSO-d6) δ (ppm): 173.0, 166.2, 159.5,
154.4, 148.7, 147.8, 137.8, 134.8, 134.4, 131.6, 128.7,
127.9, 123.1, 103.7, 41.7, 41.1, 13.4; Anal. Calc. for
C19H18ClN5OS: C, 57.07; H, 4.54; N, 17.51%;
found: C, 57.03; H, 4.84; N, 17.38%.
8. A. Khurshid, A. Saeed, J. Chin. Chem. Soc. 2017,
64, 224.
9. H. Dai, L. Y. Ye, Y. Li, Y. Fang, Y. J. Shi, Z. P. Liang,
J. Shi, Chin. J. Org. Chem. 2017, 37, 1020.
10. W. Wei, S. Zhou, D. D. Cheng, Y. X. Li, J. B. Liu,
Y. T. Xie, Y. H. Li, Z. M. Li, Bioorg. Med. Chem. Lett.
2017, 27, 3365.
11. A. A. Fadda, R. Rabie, H. A. Etman, A. S. Fouda, Res.
Chem. Intermed. 2015, 41, 740.
12. H. M. Marvaniya, P. K. Parikh, D. J. Sen, J. Appl.
Pharm. Sci. 2011, 1, 109.
13. Y. Imaeda, M. Tawada, S. Suzuki, M. Tomimoto,
M. Kondo, N. Tarui, T. Sanada, R. Kanagawa, G. Snell,
C. A. Behnke, K. Kubo, T. Kuroita, Bioorg. Med. Chem.
2016, 24, 5771.
Bioactivity assay
The in vitro fungicidal activities of the target com-
pounds 5a–5m against B. cinerea and S. sclerotiorum
were evaluated by the mycelium growth rate method
according to the literature.24 The concentrations of the
tested compounds were 50 and 100 μg/mL, respectively.
The commercial fungicide chlorothalonil was used as
positive controls, and sterile water was used as blank.
6
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Antifungal Activity of Pyrimidine-5-carboxamides
14. X. Liang, F. Lv, B. Wang, K. Yu, H. Wu, Z. Qi, Z. Jiang,
C. Chen, A. Wang, W. Miao, W. Wang, Z. Hu, J. Liu,
X. Liu, Z. Zhao, L. Wang, S. Zhang, Z. Ye, C. Wang, T. Ren,
Y. Wang, Q. Liu, J. Liu, J. Med. Chem. 2017, 60, 1793.
15. Y. Liu, Z. M. Liu, X. F. Cao, X. Liu, H. L. He,
Y. S. Yang, Bioorg. Med. Chem. Lett. 2011, 21, 4779.
16. K. Singaram, D. Marimuthu, S. Baskaran, S. Chinaga,
J. Chin. Chem. Soc. 2016, 63, 758.
17. X. H. Liu, H. F. Liu, X. Shen, B. A. Song,
P. S. Bhadury, H. L. Zhu, J. X. Liu, X. B. Qi, Bioorg.
Med. Chem. Lett. 2010, 20, 4163.
18. T. X. Li, J. Zhang, J. K. Pan, Z. X. Wu, D. Y. Hu,
B. A. Song, Eur. J. Med. Chem. 2017, 125, 657.
19. X. B. Chen, D. Q. Shi, Phosphor. Sulfur Silicon Relat.
Elem. 2008, 183, 1134.
20. Y. Xu, D. Y. Yang, X. G. Zou, C. H. Rui, Z. Y. Zhou,
Y. Q. Ma, Z. H. Qin, Pest Manag. Sci. 2017, 73, 1927.
21. A. Y. Guan, C. L. Liu, X. F. Sun, Y. Xie, M. A. Wang,
Bioorg. Med. Chem. 2016, 24, 342.
22. T. W. Hai, Y. W. Hong, R. W. Liang, M. Pu,
B. Q. Ling, Chin. J. Appl. Chem. 2015, 32, 412.
23. M. Jadhav, R. S. Kalhapure, S. Rambharose, J. Ind. Eng.
Chem. 2017, 47, 405.
24. J. L. Sun, W. Mu, Pesticide Science Experimental Tech-
niques and Guidance, Chemical Industry Press, Beijing,
2009, p. 228.
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
7