Synthesis and Biological Activities of Some Novel (E)-Alpha-(methoxyimino)benzeneacetate Derivatives with Modified 1,2,4-Triazole Moiety

Article abstract of DOI:10.1155/2014/681364

To find new strobilurin analogues with high activity against resistant pathogens, a series of (E)-α-(methoxyimino)benzeneacetate derivatives containing 1,2,4-triazole Schiff base side chain were designed and synthesized. Their structures were confirmed by

Full text of DOI:10.1155/2014/681364

Hindawi Publishing Corporation
Journal of Chemistry
Volume 2014, Article ID 681364, 9 pages
http://dx.doi.org/10.1155/2014/681364
Research Article
Synthesis and Biological Activities of Some Novel
(E)-Alpha-(methoxyimino)benzeneacetate Derivatives with
Modified 1,2,4-Triazole Moiety
Xianyou Wang,1 Hua Wang,2 Peiyun Chen,1 Yanping Pang,1
Zhilei Zhao,1 and Guangchen Wu1
1 College of Quality and Technical Supervision, Hebei University, Baoding 071002, China
2 Institute of Plant Protection and Soil Fertilizer, Hubei Academy of Agricultural Science, Wuhan 430064, China
Correspondence should be addressed to Xianyou Wang; xianyouwang@126.com
Received 6 June 2014; Revised 23 July 2014; Accepted 26 July 2014; Published 24 August 2014
Academic Editor: Gabriel Navarrete-Vazquez
Copyright © 2014 Xianyou Wang et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
To find new strobilurin analogues with high activity against resistant pathogens, a series of (E)-ꢀ-(methoxyimino)benzeneacetate
derivatives containing 1,2,4-triazole Schiff base side chain were designed and synthesized. eir structures were confirmed by IR, 1H
NMR, and 13C NMR, ESI-HRMS, or elemental analyses. Bioassays indicated that most of the target compounds showed moderate
to good fungicidal activities against Rhizoctonia solani, Botrytis cinerea Pers., Fusarium graminearum, Cotton rhizoctoniosis, and
Blumeria graminis. For example, compounds 6g and 6j exhibited promising antifungal activity against Rhizoctonia solani, Botrytis
cinerea Pers., and Fusarium graminearum. Compounds 6c, 6l, and 6m had higher fungicidal activities against Blumeria graminis at
the concentration of 50 ꢁg/mL; inhibitory rate is 91.41%, 92.13%, and 91.77%, respectively.
1. Introduction
Recently, significant research efforts focusing on struc-
tural modification of strobilurins have been devoted to over-
coming the above-mentioned problem. Moreover, according
to the literature, the methoxyiminoacetate is an effective
pharmacophore which is indispensable for antifungal activ-
ity of strobilurin fungicides. e aromatic bridge helps to
stabilize the molecule and the molecule also exhibits photo
stability. erefore, numerous studies have reported that
modification of the side chain is the most effective method
to obtain novel strobilurin derivatives with higher biological
activities [6, 12–14].
In general, 1,2,4-triazole and similar Schiff bases exhibit
diverse biological activities, such as pesticides, fungicides,
herbicidal, anticancer, anti-inflammatory, antiviral, and anti-
microbial properties [15–22]. So far, over twenty triazole
fungicides have been commercialized, like triadimefon and
triadimenol (Figure 1). erefore, based on the active sub-
structure combination and bioisosteric replacement, the inter-
mediate derivatization method was employed to synthesize a
series of novel strobilurin derivatives containing 1,2,4-triazole
e strobilurins, derived from fermentations of Strobilurus
tenacellus by Anke and coworkers in 1977, are one of the most
important classes of agricultural fungicides [1]. eir primary
mechanism of action is the inhibition of mitochondrial
respiration by blocking electron transfer at the ubiquinol
oxidation center (Qo site) of the cytochrome ꢂꢃ1 complex
(complex III) [2].
Strobilurin derivatives have attracted significant attention
of the agricultural chemists owing to their outstanding
characteristics and unique mode of action, broader antifungal
spectrum, long-lasting effects, high antifungal activity, and
low toxicity toward mammalian cells [3–6]. e strobilurins
were first commercialized in 1996 with the launch of azoxys-
trobin and kresoxim-methyl (Figure 1) [7]. Till date, over
ten strobilurin derivatives are commercially available [8–10].
However, following the use of strobilurin fungicides in a short
period of field applications, significant increase in resistance
to fungicide has been observed [11].

2
Journal of Chemistry
O
H
O
N
N
O
N
O
N
O
Cl
Cl
O
O
O
N
O
N
O
CN
O
N
N
N
O
O
Azoxystrobin
Kresoxim-methyl
Triadimefon
Triadimenol
Figure 1: Structures of azoxystrobin, kresoxim-methyl, triadimefon, and triadimenol.
Br
O
O
O
N
N
O
O
O
N N
ꢀ-Methoxyacrylate
S
N
NH
R
N
N
S
N
N
R
Lead compound
6a–6n
Figure 2: Design strategy of the title compounds.
moieties. Moreover, strobilurin pharmacophores were designed
and synthesized with the objective of obtaining more active
candidates against resistant fungal strains (Figure 2). e
results of bioassays revealed that most of the (E)-ꢀ-(methox-
yimino)benzeneacetate derivatives exhibited potential anti-
fungal activities against Rhizoctonia solani, Botrytis cinerea
Pers., Fusarium graminearum, Cotton rhizoctoniosis, and
Blumeria graminis.
2.3. General Method for the Synthesis of Potassium Dithio-
carbazinate (3) [24]. Potassium hydroxide (0.15 mol) was
dissolved in absolute ethanol (100 mL) followed by the addi-
tion of benzohydrazide 2 (0.1 mol). e resulting solution
was cooled in ice. Subsequently, carbon disulfide (0.15 mol)
was added dropwise, and the reaction mixture was stirred
for 15 h at room temperature. e precipitated potassium
dithiocarbazinate was collected by filtration. e precipitate
was further washed with anhydrous ether (100 mL), dried,
and used directly without purification for the subsequent
reaction.
2. Experimental
2.1. General Information. All melting points were deter-
mined on an XT-4A apparatus and are uncorrected. e
IR spectra (KBr disks) were taken on a Bruker Equinox 55
spectrophotometer. e 1H NMR spectra were measured on
a Bruker Advance 600 spectrometer for DMSO-d6 solutions
using TMS as internal standard. Elemental analyses were
determined on a Flash-1112 series elemental analyzer. All
the reagents used were AR grade. Molecular weights of
monomers were determined by high resolution mass spec-
troscopy (ESI-HRMS, Bruker daltonics apexultra 7.0 tesla
Fourier transform ion cyclotron resonance mass spectrom-
eter). e completion of reactions was monitored by TLC.
2.4. Synthesis of 4-Amino-3-phenyl-5-thiol-1,2,4-triazole (4)
[25]. Potassium dithiocarbazinate 3 (0.5 mol) was added to
hydrazine hydrate (0.15 mmol) and refluxed for 6 h with occa-
sional shaking. e color of the reaction mixture changed to
green with the evolution of hydrogen sulfide gas (lead acetate
paper test and odor). e reaction mixture was cooled to
room temperature and diluted with water. On acidification
with concentrated hydrochloric acid, the corresponding tria-
zole was precipitated. It was filtered, washed thoroughly with
cold water, and recrystallized from ethanol to give 4-amino-
3-phenyl-5-thiol-1,2,4-triazole 4. White crystal, yield: 63.1%,
1
m.p.: 201-202∘C; IR (KBr, cm−1): 3412, 3070, 2667, 1640. H
NMR (600 MHz, DMSO-d6) ꢁ: 13.90 (s, 1H, triazole–NH),
2.2. General Procedure for the Synthesis of Benzohydrazide (2)
[23]. A mixture of ethyl benzoate 1 (0.1 mol) and hydrazine
hydrate (0.1 mol) in ethanol (30 mL) was stirred vigorously
for 6 h at room temperature. e mixture was filtered, and the
solid was washed with cold water, dried, and recrystallized
from ethanol to give intermediate 2, white crystal, yield:
90.6%, m.p.: 112–114∘C.
7.52–8.01 (m, 5H, Ar-H), 5.81 (s, 2H, NH ).
2
2.5. General Method for the Preparation of (E)-3-iol-4-
arylideneamino-5-phenyl-4H-1,2,4-triazole (5a–5n). Appro-
priate benzaldehyde (10 mmol) and 2 to 3 drops of glacial
acetic acid were added to a solution of compound 4 (l0 mmol)

Journal of Chemistry
3
dissolved in absolute alcohol (30 mL). e mixture was
refluxed for 4 h with stirring. e solid that was obtained
on cooling was filtered, washed with cold water, dried, and
recrystallized from alcohol to give a series of Schiff bases 5a–
5n.
DMSO-d6) ꢀ: 115.09, 117.22, 120.90, 128.21, 128.24, 128.42,
130.41, 130.87, 136.96, 144.85, 155.92, 157.36, 165.12. Anal. calcd
for C H N OS: C, 60.79; H, 4.08; N, 18.91; found: C, 60.71;
15 12
4
H, 4.11; N, 18.89.
(E)-3-iol-4-(4-hydroxylbenzylideneamino)-5-phenyl-4H-1,2,
4-triazole (5f ). White powder, yield: 68.8%, m.p.: 245-246∘C.
IR (KBr, cm−1): 3129, 3102, 2985, 1611, 1557, 1532, 1483, 1270.
(E)-3-iol-4-benzylideneamino-5-phenyl-4H-1,2,4-triazole
(5a). White powder, yield: 70.0%, m.p.: 180-181∘C. IR (KBr,
1
cm−1): 3102, 2974, 1610, 1554, 1530, 1482, 1269. H NMR
1H NMR (600 MHz, DMSO-d6) ꢀ: 7.17 (d, ꢁ = =.0 Hz,
(600 MHz, DMSO-d6) ꢀ: 7.43–7.71 (m, 6H, Ar-H), 7.90 (d,
1H, Ar-H), 7.40–7.60 (m, 6H, Ar-H), 7.88–7.90 (m, 2H,
ꢁ = 7.8 Hz, 4H, Ar-H), 9.71 (s, 1H, CH=N), 14.25 (s, 1H,
triazole–NH). 13C NMR (125 MHz, DMSO-d6) ꢀ: 127.71,
128.22, 128.26, 128.33, 128.44, 129.47, 130.85, 134.39, 144.82,
154.73, 165.12. Anal. calcd for C H N S: C, 64.26; H, 4.31;
Ar-H), 9.49 (s, 1H, CH=N), 10.41 (s, 1H, OH), 14.24 (s, 1H,
triazole–NH). 13C NMR (125 MHz, DMSO-d6) ꢀ: 115.11,
126.48, 128.21, 128.24, 128.43, 128.85, 130.84, 144.85, 154.74,
159.05, 165.11. Anal. calcd for C H N OS: C, 60.79; H, 4.08;
15 12
4
15 12
4
N, 19.98; found: C, 64.31; H, 4.29; N, 19.93.
N, 18.91; found: C, 60.73; H, 4.12; N, 19.00.
(E)-3-iol-4-(4-methylbenzylideneamino)-5-phenyl-4H-1,2,4-
(E)-3-iol-4-(2-nitrobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5g). Pale yellow needle crystal, yield: 82.1%, m.p.:
214-215∘C. IR (KBr, cm−1): 3113, 2974, 1614 1554, 1530, 1482,
1270. 1H NMR (600 MHz, DMSO-d6) ꢀ: 6.94 (d, ꢁ = 8.6 Hz,
triazole (5b). Red solid, yield: 62.5%, m.p.: 239-240∘C. IR
(KBr, cm−1): 3110, 2979, 1618, 1516, 1512, 1484, and 1271. H
1
NMR (600 MHz, DMSO-d6) ꢀ: 2.41 (s, 3H, CH ), 7.46–7.58
3
(m, 3H, Ar-H), 7.66 (t, ꢁ = 13.6 Hz, 2H, Ar-H), 7.86 (dd,
2H, Ar-H), 7.49–7.58 (m, 3H, Ar-H), 7.75 (d, ꢁ = 8.6 Hz, 2H,
ꢁ = 13.2, 11.7 Hz, 2H, Ar-H), 7.92 (d, ꢁ = 8.4 Hz, 2H, Ar-H),
Ar-H), 7.86–7.90 (m, 2H, Ar-H), 9.58 (s, 1H, CH=N), 14.32 (s,
9.62 (s, 1H, CH=N), 14.21 (s, 1H, triazole–NH). 13C NMR
(125 MHz, DMSO-d6) ꢀ: 21.16, 128.03, 128.22, 128.25, 128.42,
128.61, 130.82, 131.71, 137.95, 144.87, 154.73, 165.12. Anal. calcd
for C H N S: C, 65.28; H, 4.79; N, 19.03; found: C, 65.33;
1H, triazole–NH). 13C NMR (125 MHz, DMSO-d6) ꢀ: 126.45,
127.11, 127.83,. 128.22, 128.25, 128.42, 130.87, 131.67, 133.54,
140.25, 144.83, 146.91, 165.12. Anal. calcd for C H N O S:
15 11
5
2
C, 55.38; H, 3.41; N, 21.53; found: C, 55.34; H, 3.46; N, 21.59.
16 14
4
H, 4.77; N, 18.99.
(E)-3-iol-4-(3-nitrobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5h). Pale yellow needle crystal, yield: 72.3%, m.p.:
214-215∘C. IR (KBr, cm−1): 3108, 2972, 1620, 1557, 1538, 1487,
1269. 1H NMR (600 MHz, DMSO-d6) ꢀ: 7.42 (t, ꢁ = 8.8 Hz,
(E)-3-iol-4-(4-dimethylaminobenzylideneamino)-5-phenyl-
4H-1,2,4-triazole (5c). White solid, yield: 75.1%, m.p.:
233-234∘C. IR (KBr, cm−1): 3113, 2978, 1613 1552 1531, 1482,
1
1275. H NMR (600 MHz, DMSO-d6) ꢀ: 3.34 (s, 6H, N-
2H, Ar-H), 7.47–7.61 (m, 3H, Ar-H), 7.88 (d, ꢁ = 7.6 Hz, 2H,
Ar-H), 7.99–8.12 (m, 2H, Ar-H), 9.71 (s, 1H, CH=N), 14.32
(s, 1H, triazole–NH). 13C NMR (125 MHz, DMSO-d6) ꢀ:
125.88, 126.76, 128.22, 128.24, 128.44, 129.11, 130.83, 132.97,
135.83, 144.85, 146.87, 155.94, and 165.12. Anal. calcd for
C H N O S: C, 55.38; H, 3.41; N, 21.53; found: C, 55.42; H,
(CH ) ), 7.09 (t, ꢁ = 7.3 Hz, 1H, Ar-H), 7.22 (d, ꢁ = 8.4 Hz,
3 2
1H, Ar-H), 7.44–7.70 (m, 4H, Ar-H), 7.90–7.92 (m, 3H, Ar-H),
9.50 (s, 1H, CH=N), 14.28 (s, 1H, triazole–NH). 13C NMR
(125 MHz, DMSO-d6) ꢀ: 41.92, 111.93, 120.04, 128.22, 128.24,
128.27, 128.42, 130.84, 144.84, 153.11, 154.72, 165.11. Anal. calcd
for C H N S: C, 63.13; H, 5.30; N, 21.65; found: C,63.20; H,
15 11
5
2
3.39; N, 21.48.
17 17
5
5.26; N, 21.59.
(E)-3-iol-4-(4-nitrobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5i). Red powder, Yield: 77.6%, m.p.: 238-239∘C.
(E)-3-iol-4-(2-hydroxylbenzylideneamino)-5-phenyl-4H-1,2,
IR (KBr, cm−1): 3111, 2971 1610, 1552 1537, 1487, 1269; H
1
4-triazole (5d). White needle crystal, yield: 78.4%, m.p.:
195-196∘C. IR (KBr, cm−1): 3122, 3102, 2977, 1620, 1550, 1531,
NMR (600 MHz, DMSO-d6) ꢀ: 7.45–7.72 (m, 6H, Ar-H),
1486, 1269. 1H NMR (600 MHz, DMSO-d6) ꢀ: 6.82–7.10 (m,
7. 82−7.94 (m, 2H, Ar-H), 8.07 (d, ꢁ = 7.5 Hz, 1H, Ar-H),
2H, Ar-H), 7.45 (t, ꢁ = 7.7 Hz, 1H, Ar-H), 7.54–7.56 (m, 3H,
Ar-H), 7.73–7.93 (m, 3H, Ar-H), 9.65 (s, 1H, CH=N), 10.47 (s,
1H, Ar-OH), 14.21 (s, 1H, triazole–NH). 13C NMR (125 MHz,
DMSO-d6) ꢀ: 116.25, 119.62, 121.01, 128.24, 128.24, 128.46,
129.65, 130.86, 131.03, 144.85, 146.81, 159.93, 165.12. Anal. calcd
for C H N OS: C, 60.79; H, 4.08; N, 18.91; found: C, 60.73;
9.55 (s, 1H, CH=N), 14.34 (s, 1H, triazole–NH). 13C NMR
(125 MHz, DMSO-d6) ꢀ: 123.72, 127.87, 128.23, 128.25, 128.42,
130.86, 138.93, 144.82, 146.85, 154.73, 165.12. Anal. calcd for
C H N O S: C, 55.38; H, 3.41; N, 21.53; found: C, 55.32; H,
15 11
5
2
3.45; N, 21.56
15 12
4
H, 4.10; N, 18.94.
(E)-3-iol-4-(2-chlorobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5j). Pale yellow needle crystal, yield: 73.1%, m.p.:
199-200∘C. IR (KBr, cm−1): 3110, 2971, 1614, 1552, 1538, 1483,
(E)-3-iol-4-(3-hydroxylbenzylideneamino)-5-phenyl-4H-1,2,
1
4-triazole (5e). White needle crystal, yield: 65.8%, m.p.:
1269. H NMR (600 MHz, DMSO-d6) ꢀ: 7.45–7.63 (m, 3H,
205-206∘C. IR (KBr, cm−1): 3120, 3100, 2987, 1622, 1549, 1536,
Ar-H), 7.80–7.93 (m, 2H, Ar-H), 8.15 (d, ꢁ = 8.7 Hz, 2H,
1487, 1278. 1H NMR (600 MHz, DMSO-d6) ꢀ: 7.02–7.20 (m,
Ar-H), 8.38 (d, ꢁ = 8.6 Hz, 2H, Ar-H), 9.78 (s, 1H, CH=N),
2H, Ar-H), 7.49 (t, ꢁ = 7.6 Hz, 1H, Ar-H), 7.52–7.61 (m, 4H,
Ar-H), 7.76–7.98 (m, 2H, Ar-H), 9.65 (s, 1H, CH=N), 10.42 (s,
1H, Ar-OH), 14.22 (s, 1H, triazole–NH). 13C NMR (125 MHz,
14.31 (s, 1H, triazole–NH). 13C NMR (125 MHz, DMSO-d6)
ꢀ: 127.61, 128.21, 128.22, 128.43, 129.07, 129.18, 129.53, 130.43,
130.84, 133.24, 144.86, 150.17, and 165.12. Anal. calcd for

4
Journal of Chemistry
C H ClN S: C, 57.23; H, 3.52; N, 17.80; found: C, 57.28; H,
extracted with ethyl acetate (3 × 100 mL). e combined
extracts were washed with brine, dried (anhydrous
magnesium sulfate), and filtered. e filtrate was evaporated,
and the crude product was purified by silica gel column
chromatography using a 1 : 3 (v/v) mixture of ethyl acetate
and petroleum ether (boiling point range 60–90∘C) as the
eluting solution to obtain compound 6.
15 11
4
3.54; N, 17.75.
(E)-3-iol-4-(3-chlorobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5k). Pale yellow needle crystal, Yield: 69.2%, m.p.:
210-211∘C. IR (KBr, cm−1): 3106, 2969, 1618, 1553, 1542, 1488,
1
1279. H NMR (600 MHz, DMSO-d6) ꢀ: 7.40–7.61 (m, 3H,
Ar-H), 7.78–7.90 (m, 3H, Ar-H), 8.09 (d, ꢁ = 8.8 Hz, 1H,
Ar-H), 8.38 (d, ꢁ = 8.4 Hz, 2H, Ar-H), 9.76 (s, 1H, CH=N),
14.29 (s, 1H, triazole–NH). 13C NMR (125 MHz, DMSO-
d6) ꢀ: 126.45, 127.48, 128.22, 128.25, 128.42, 129.12, 129.51,
130.85, 134.33, 135.06, 144.84, 155.93, 165.12. Anal. calcd for
C H ClN S: C, 57.23; H, 3.52; N, 17.80; found: C, 57.20; H,
(E)-Methyl-2-(3-((4-((E)-benzylideneamino)-5-phenyl- 4H-1,2,
4-triazol-3-ylthio)methyl)phenyl)-2-(methoxyimino)acetate
(6a). White solid, yield: 61.1%, m.p.: 94-95∘C. IR (KBr,
cm−1): 3103, 2964, 1655, 1611, 1554, 1514, 1478, 1274. 1H NMR
(600 MHz, DMSO-d6) ꢀ: 3.64 (s, 3H, COOCH ), 3.90 (s, 3H,
15 11
4
3
3.49; N, 17.76.
=N-OCH ), 4.30 (s, 2H, CH ), 7.18 (t, ꢁ = 15.8 Hz, 1H, Ar-H),
3
2
7.31–7.36 (m, 2H, Ar-H), 7.45–7.71 (m, 7H, Ar-H), 7.85–8.14
(m, 4H, Ar-H), 8.74 (s, 1H, CH=N). 13C NMR (125 MHz,
DMSO-d6) ꢀ: 33.68, 52.18, 60.41, 127.73, 128.16, 128.31,
128.31, 128.34, 128.66, 128.78, 129.47, 130.64, 130.79, 130.93,
131.14, 134.35, 140.63, 149.72, 152.49, 158.56, 159.58, 163.67.
(E)-3-iol-4-(4-chlorobenzylideneamino)-5-phenyl-4H-1,2,4-
triazole (5l). Pale yellow needle crystal, yield: 68.2%, m.p.:
221-222∘C. IR (KBr, cm−1): 3100, 2979, 1611, 1551, 1537, 1481,
1
1269. H NMR (600 MHz, DMSO-d6) ꢀ; 7.46–7.68 (m, 5H,
+
Ar-H), 7.85–7.87 (m, 3H, Ar-H), 8.04 (d, ꢁ = 8.5 Hz, 1H,
Ar-H), 9.78 (s, 1H, CH=N), 14.26 (s, 1H, triazole–NH). 13C
NMR (125 MHz, DMSO-d6) ꢀ: 128.21, 128.22, 128.41, 128.59,
128.63, 130.85, 134.16, 135.34, 144.85, 154.74, 165.12. Anal.
calcd for C H ClN S: C, 57.23; H, 3.52; N, 17.80; found: C,
ESI-HRMS calcd. for C H N O S [M + H] 486.15944;
26 24
5
3
found: 486.15877.
(E)-Methyl-2-(2-(((4-((E)-(4-methylbenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6b). White solid, yield: 61.2%, m.p.:
119-120∘C. IR (KBr, cm−1): 3113, 2963, 1653, 1602, 1567, 1525,
15 11
4
57.21; H, 3.57; N, 17.77.
1
(E)-3-iol-4-(2,4-dichlorobenzylideneamino)-5-phenyl-4H-
1,2,4-triazole (5m). Pale yellow needle crystal, yield: 69.0%,
m.p.: 222-223∘C. IR (KBr, cm−1): 3107, 2985, 1620, 1563,
1486, 1285. H NMR (600 MHz, DMSO-d6) ꢀ: 2.97 (s, 3H,
Ar-CH ), 3.65 (s, 3H, COOCH ), 3.90 (s, 3H, =N-OCH ),
3
3
3
4.29 (s, 2H, CH ), 7.16 (d, ꢁ = 7.5 Hz, 1H, ArH), 7.32–7.41 (m,
2
1
1523, 1481, 1274. H NMR (600 MHz, DMSO-d6) ꢀ: 7.42 (t,
4H, Ar-H), 7.46–7.52 (m, 3H, Ar-H), 7.54 (d, ꢁ = 7.5 Hz, 1H,
Ar-H), 7.76 (d, ꢁ = 8.1 Hz, 2H, ArH), 7.81–7.85 (m, 2H, Ar-H),
8.68 (s, 1H, CH=N). 13C NMR (125 MHz, DMSO-d6) ꢀ:
21.25, 33.71, 52.04, 60.45, 128.04, 128.18, 128.32, 128.33, 128.61,
128.67, 128.74, 130.65, 130.77, 130.93, 131.11, 131.73, 137.93,
140.63, 149.74, 152.49, 158.56, 159.53, 163.50. ESI-HRMS calcd.
ꢁ = 12.1 Hz, 1H, Ar-H), 7.48–7.60 (m, 4H, Ar-H), 7.64–7.67
(m, 1H, Ar-H), 7.92–8.13 (m, 2H, Ar-H), 9.75 (s, 1H, CH=N),
14.31 (s, 1H, triazole–NH). 13C NMR (600 MHz, DMSO-
d6) ꢀ: 128.21, 128.23, 128.10, 128.22, 128.23, 128.44, 130.86,
132.96, 133.54, 134.96, 144.82, 153.94, 165.13. Anal. calcd for
C H Cl N S: C, 51.59; H, 2.89; N, 16.04; found: C, 51.53; H,
+
for C H N O S [M + H] 500.17509; found: 500.17536.
15 10
2
4
27 26
5
3
2.92; N, 16.08.
(E)-Methyl-2-(2-(((4-((E)-(4-(dimethylamino)benzylidene)
amino)-5-phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-
2-(methoxyimino)acetate (6c). White solid, yield: 73.2%,
m.p.: 140-141∘C. IR (KBr, cm−1): 3105, 2955, 1652, 1612, 1539,
(E)-3-iol-4-(3,4-dichlorobenzylideneamino)-5-phenyl-4H-
1,2,4-triazole (5n). White needle crystal, yield: 84.8%, m.p.:
205-206∘C. IR (KBr, cm−1): 3112, 2971, 1612, 1554, 1537, 1481,
1275. 1H NMR (600 MHz, DMSO-d6) ꢀ: 7.39 (d, ꢁ = 7.8 Hz,
2H, Ar-H), 7.52–754 (m, 2H, Ar-H), 7.79 (d, ꢁ = 7.9 Hz, 2H,
Ar-H), 7.84–7.94 (m, 2H, Ar-H), 9.62 (s, 1H, CH=N), 14.29 (s,
1H, triazole–NH). 13C NMR (125 MHz, DMSO-d6) ꢀ: 126.81,
128.04, 128.10, 128.22, 128.26, 128.43, 130.86, 132.95, 133.54,
134.97, 144.84, 155.94, 165.12. Anal. calcd for C H Cl N S:
1
1514, 1491, 1288. H NMR (600 MHz, DMSO-d6) ꢀ: 3.11 (s,
6H, N-(CH ) ), 3.67 (s, 3H, COOCH ), 3.91 (s, 3H, =N-
3 2
3
OCH ), 4.26 (s, 2H, CH ), 6.80 (d, ꢁ = 9.0 Hz, 2H, Ar-H),
3
2
7.16 (d, ꢁ = 7.5 Hz, 1H, Ar-H), 7.33–7.41 (m, 2H, Ar-H),
7.43–7.52 (m, 3H, Ar-H), 7.55 (d, ꢁ = 7.4 Hz, 1H, Ar-H), 7.67
(d, ꢁ = 8.9 Hz, 2H, Ar-H), 7.84 (d, ꢁ = 7.9 Hz, 2H, Ar-H),
8.43 (s, 1H, CH=N). 13C NMR (125 MHz, DMSO-d6) ꢀ:
33.71, 41.93, 52.06, 60.44, 111.93, 120.02, 128.15, 128.26, 128.33,
128.34, 128.66, 128.78, 130.61, 130.73, 130.97, 131.19, 140.69,
149.74, 152.46, 153.15, 158.56, 159.53, 163.57. ESI-HRMS calcd.
15 10
2
4
C, 51.59; H, 2.89; N, 16.04; found: C, 51.55; H, 2.85; N, 16.01.
2.6. General Procedure for the Synthesis of Target Compounds
(6a–6n). (E)-3-iol-4-arylideneamino-5-phenyl-4H-1,2,4-
triazole 5 (1.75 mmol) was dissolved in DMF (15 mL), and
anhydrous potassium carbonate (0.24 g, 1.75 mmol) was
added to the solution. e solution was stirred for 0.5 h and
(E)-methyl-2-(2-(bromomethyl)phenyl)-2-(methoxyimino)
acetate (0.50 g, 1.75 mmol) was then added. e reaction mix-
ture was heated to 80∘C and monitored by TLC. Afer 1 h,
the mixture was cooled, diluted with water (30 mL), and
+
for C H N O S [M + H] 529.20164; found: 529.20172.
28 29
6
3
(E)-Methyl-2-(2-(((4-((E)-(2-hydroxybenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6d). White solid, yield: 70.2%, m.p.: 117-
118∘C. IR (KBr, cm−1): 3110, 2952, 1650, 1607, 1541, 1527,
1
1486, 1282. H NMR (600 MHz, DMSO-d6) ꢀ: 3.68 (s, 3H,
COOCH ), 3.92 (s, 3H, =N-OCH ), 4.31 (s, 2H, CH ),
3
3
2

Journal of Chemistry
5
6.96–7.10 (m, 2H, Ar-H), 7.17 (d, ꢀ = 7.4 Hz, 1H, Ar-H),
7.31–7.54 (m, 6H, Ar-H), 7.56 (d, ꢀ = 7.5 Hz, 2H, Ar-H), 7.83
(d, ꢀ = 7.3 Hz, 2H, Ar-H), 8.86 (s, 1H, CH=N), 10.52 (s, 1H,
Ar-OH). 13C NMR (125 MHz, DMSO-d6) ꢁ: 33.72, 42.16,
52.03, 60.42, 85.38, 116.27, 119.65, 121.04, 128.17, 128.37, 128.63,
128.71, 129.68, 130.63, 130.77, 130.94, 131.06, 131.13, 140.64,
149.75, 150.16, 152.47, 158.53, 159.94, 163.56. ESI-HRMS calcd.
112-113∘C. IR (KBr, cm−1): 3105, 2959, 1652, 1609, 1557, 1523,
1
1482, 1275. H NMR (600 MHz, DMSO-d6) ꢁ: 3.66 (s, 3H,
COOCH ), 3.91 (s, 3H, =N-OCH ), 4.30 (s, 2H, CH ), 7.17
3
3
2
(d, ꢀ = 7.6 Hz, 1H, Ar-H), 7.30–7.41 (m, 2H, Ar-H), 7.47–7.55
(m, 4H, Ar-H), 7.81–7.92 (m, 3H, Ar-H), 8.31 (d, ꢀ = 7.8 Hz,
1H, Ar-H), 8.48 (d, ꢀ = 8.2 Hz, 1H, Ar-H), 8.65 (s, 1H,
ArH), 8.92 (s, 1H, CH=N). 13C NMR (125 MHz, DMSO-d6)
ꢁ: 33.71, 52.08, 60.41, 123.87, 124.67, 128.19, 128.35, 128.36,
128.65, 128.78, 129.10, 130.65, 130.74, 130.93, 131.13, 132.97,
135.86, 140.63, 146.85, 149.75, 152.46, 158.54, 160.05, 163.56.
+
for C H N O S [M + H] 502.15435: found: 502.15344.
26 24
5
4
(E)-Methyl-2-(2-(((4-((E)-(3-hydroxybenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6e). White solid, yield: 69.3%, m.p.:126-
127∘C. IR (KBr, cm−1): 3109, 2956, 1651, 1612, 1542, 1523,
+
ESI-HRMS calcd. for C H N O S [M + H] 531.14451;
26 23
6
5
found: 531.14415.
1
1481, 1280. H NMR (600 MHz, DMSO-d6) ꢁ: 3.68 (s, 3H,
(E)-Methyl-2-(2-(((4-((E)-(4-nitrobenzylidene)amino)-5-phe-
nyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methoxyim-
ino)acetate (6i). Yellow solid, yield: 78.5%, m.p.: 140-141∘C.
IR (KBr, cm−1): 3103, 2957, 1648, 1614, 1567, 1528, 1491, 1273.
COOCH ), 3.92 (s, 3H, =N-OCH ), 4.31 (s, 2H, CH ),
3
3
2
6.99 (d, ꢀ = 7.5 Hz, 1H, Ar-H), 7.29–7.38 (m, 2H, Ar-H),
7.50–7.52 (m, 5H, Ar-H), 7.61–7.76 (m, 3H, ArH), 7.85 (d,
ꢀ = 6.4 Hz, 2H, Ar-H), 8.73 (s, 1H, CH=N), 10.50 (s, 1H,
Ar-OH). 13C NMR (125 MHz, DMSO-d6) ꢁ: 33.74. 52.05,
60.43, 115.08, 117.21, 120.93, 128.19, 128.29, 128.34, 128.66,
128.78, 130.41, 130.63, 130.76, 130.97, 131.18, 136.93, 140.63,
149.74, 152.47, 157.35, 158.56, 160.02, 163.55. ESI-HRMS calcd.
1H NMR (600 MHz, DMSO-d6) ꢁ: 3.65 (s, 3H, COOCH ),
3
3.91 (s, 3H, =N-OCH ), 4.31 (s, 2H, CH ), 7.16 (d, ꢀ = 7.5 Hz,
3
2
1H, Ar-H), 7.31–7.40 (m, 2H, Ar-H), 7.45–7.58 (m, 4H, Ar-H),
7.82 (d, ꢀ = 9.5, 2H, Ar-H), 8.12 (d, ꢀ = 8.8 Hz, 2H, Ar-H),
8.40 (d, ꢀ = 8.8 Hz, 2H, Ar-H), 8.89 (s, 1H, CH=N). 13C
NMR (125 MHz, DMSO-d6) ꢁ: 33.71, 52.08, 60.42, 123.73,
127.85, 128.18, 128.36, 128.34, 128.66, 128.78, 130.66, 130.79,
130.93, 131.13, 138.94, 140.63, 146.84, 149.75, 152.49, 158.56,
+
for C H N O S [M + H] 502.15435: found: 502.15422.
26 24
5
4
(E)-Methyl-2-(2-(((4-((E)-(4-hydroxybenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6f ). White solid, yield: 71.0%, m.p.: 143-
144∘C. IR (KBr, cm−1): 3113, 2953, 1658, 1600, 1546, 1513,
+
159.58, 163.58. ESI-HRMS calcd. for C H N O S [M + H]
26 23
6
5
531.14451; found: 531.14434.
1
1480, 1278. H NMR (600 MHz, DMSO-d6) ꢁ: 3.66 (s, 3H,
COOCH ), 3.91 (s, 3H, =N-OCH ), 4.28 (s, 2H, CH ), 6.94
3
3
2
(E)-Methyl-2-(2-(((4-((E)-(2-chlorobenzylidene)amino)-5-phe-
nyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methoxyim-
ino)acetate (6j). Pale yellow solid, yield: 63.2%, m.p.: 122-
123∘C. IR (KBr, cm−1): 3122, 2956, 1650, 1612, 1557, 1524,
(d, ꢀ = 8.6 Hz, 2H, Ar-H), 7.17 (d, ꢀ = 7.5 Hz, 1H, Ar-H),
7.30–7.41 (m, 2H, Ar-H), 7.44–7.52 (m, 3H, Ar-H), 7.55 (d,
ꢀ = 7.6 Hz, 1H, Ar-H), 7.73 (d, ꢀ = 8.7 Hz, 2H, Ar-H),
7.84 (d, ꢀ = 8.0 Hz, 2H, Ar-H), 8.55 (s, 1H, CH=N), 10.37
(s, 1H, Ar-OH). 13C NMR (125 MHz, DMSO-d6) ꢁ: 33.72,
52.08, 60.42, 115.12, 126.43, 128.19, 128.35, 128.34, 128.65,
128.78, 128.84, 130.66, 130.77, 130.94, 131.13, 140.65, 149.76,
152.49, 158.56, 159.04, 159.57, 163.56. ESI-HRMS calcd. for
C H N O S [M+H]+ 502.15435; found: 502.15425.
1
1498, 1281. H NMR (600 MHz, DMSO-d6) ꢁ: 3.67 (s, 3H,
COOCH ), 3.92 (s, 3H, =N-OCH ), 4.34 (s, 2H, CH ), 7.09–
3
3
2
7.21 (m, 1H, Ar-H), 7.33–7.40 (m, 2H, Ar-H), 7.48–7.71 (m,
7H, Ar-H), 7.82 (d, ꢀ = 7.5, 2H, Ar-H), 8.05 (d, ꢀ = 7.5 Hz,
1H), 8.95 (s, 1H, CH=N). 13C NMR (125 MHz, DMSO-d6)
ꢁ: 33.71, 52.08, 60.41, 127.68, 128.14, 128.32, 128.35, 128.66,
128.78, 129.07, 129.14, 129.52, 130.43, 130.65, 130.77, 130.95,
131.13, 133.23, 140.63, 149.75, 152.48, 155.05, 158.54, 163.56.
26 24
5
4
(E)-Methyl-2-(2-(((4-((E)-(2-nitrobenzylidene)amino)-5-phe-
nyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methoxyim-
ino)acetate (6g). Pale yellow solid, yield: 77.2%, m.p.: 143-
144∘C. IR (KBr, cm−1): 3112, 2953, 1656, 1612, 1557, 1519,
+
ESI-HRMS calcd. for C H ClN O S [M + H] 520.12046;
26 23
5
3
found: 520.12032.
1
1493, 1280. H NMR (600 MHz, DMSO-d6) ꢁ: 3.69 (s, 3H,
COOCH ), 3.93 (s, 3H, =N-OCH ), 4.33 (s, 2H, CH ), 7.18
(E)-Methyl-2-(2-(((4-((E)-(3-chlorobenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6k). Pale yellow solid, yield: 60.9%, m.p.:
126-127∘C. IR (KBr, cm−1): 3117, 2961, 1652, 1623, 1555, 1529,
3
3
2
(d, ꢀ = 7.5 Hz, 1H, Ar-H), 7.33–7.40 (m, 2H, Ar-H), 7.49–7.59
(m, 4H, Ar-H), 7.76–7.83 (m, 2H, Ar-H), 7.84–7.92 (m, 1H,
Ar-H), 7.93 (t, ꢀ = 17.8 Hz, 1H, Ar-H), 8.04 (d, ꢀ = 7.7 Hz,
1H, Ar-H), 8.21 (d, ꢀ = 8.1 Hz, 1H, Ar-H), 9.05 (s, 1H, CH=N).
13C NMR (125 MHz, DMSO-d6) ꢁ: 33.73, 52.08, 60.40,
126.44, 127.13, 127.80, 128.19, 128.32, 128.33, 128.64, 128.73,
130.65, 130.72, 130.93, 131.13, 131.65, 133.55, 140.64, 146.90,
148.45, 149.75, 152.47, 158.56, 163.58. ESI-HRMS calcd. for
1
1492, 1284. H NMR (600 MHz, DMSO-d6) ꢁ: 3.63 (s, 3H,
COOCH ), 3.89 (s, 3H, =N-OCH ), 4.32 (s, 2H, CH ), 7.17
3
3
2
(d, ꢀ = 7.4 Hz, 1H, Ar-H), 7.30–7.41 (m, 2H, Ar-H), 7.46–7.57
(m, 5H, Ar-H), 7.75–7.82 (m, 2H, Ar-H), 7.92 (d, ꢀ 1=3 7.5 Hz,
2H, Ar-H), 8.05 (s, 1H, Ar-H), 8.85 (s, 1H, CH=N). C NMR
(125 MHz, DMSO-d6) ꢁ: 33.72, 52.05, 60.44, 126.43, 127.44,
128.18, 128.31, 128.33, 128.66, 128.78, 129.13, 129.51, 130.65,
130.77, 130.98, 131.12, 134.32, 135.05, 140.62, 149.75, 152.49,
158.56, 160.02, 163.56. ESI-HRMS calcd. for C H ClN O S
+
C H N O S [M + H] 531.14451; found: 531.14424.
26 23
6
5
(E)-Methyl-2-(2-(((4-((E)-(3-nitrobenzylidene)amino)-5-phe-
nyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methoxyim-
ino)acetate (6h). Pale yellow solid, yield: 62.3%, m.p.:
26 23
5
3
+
[M + H] 520.12046; found: 520.12031.

6
Journal of Chemistry
Table 1: Fungicidal activities of 6a–6n (inhibition rate/%, 50 ꢀg mL−1).
Cotton
Entry
Rhizoctonia solani
Botrytis cinerea Pers.
Fusarium graminearum
Blumeria graminis
rhizoctoniosis
6a
6b
6c
6d
6e
6f
6g
6h
6i
6j
6k
6l
6m
6n
26.87
15.37
13.43
21.94
18.32
17.46
48.96
26.45
11.94
47.91
35.65
17.91
12.73
20.91
13.64
43.64
40.21
22.73
62.73
39.09
19.09
60.45
45.31
16.36
37.27
22.73
81.69
17.13
15.31
8.67
37.13
33.49
91.41
25.31
31.60
43.49
37.13
13.02
82.63
33.49
45.46
92.13
91.77
43.49
100
17.03
15.23
9.31
18.78
15.45
11.13
19.43
18.69
19.34
25.31
23.49
10.00
19.67
17.98
17.13
60.13
23.49
12.36
59.54
38.64
12.76
11.67
17.13
27.91
27.46
65.32
11.49
12.31
61.56
Kresoxim-methyl
73.36
1
(E)-Methyl-2-(2-(((4-((E)-(4-chlorobenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6l). Pale yellow solid, yield: 70.1%, m.p.:
131-132∘C. IR (KBr, cm−1): 3112, 2952, 1654, 1601, 1552, 1522,
1479, 12820. 1H NMR (600 MHz, DMSO-d6) ꢁ: 3.65 (s, 3H,
COOCH ), 3.90 (s, 3H, =N-OCH ), 4.29 (s, 2H, CH ), 7.17
1498, 1279. H NMR (600 MHz, DMSO-d6) ꢁ: 3.58 (s, 3H,
COOCH ), 3.91 (s, 3H, =N-OCH ), 4.29 (s, 2H, CH ), 7.17
3
3
2
(d, ꢂ = 7.4 Hz, 1H, Ar-H), 7.31–7.40 (m, 2H, Ar-H), 7.46–7.55
(m, 4H, Ar-H), 7.81–7.84 (m, 2H, Ar-H), 7.85 (d, ꢂ 1=3 9.2 Hz,
2H, Ar-H), 8.09 (s, 1H, Ar-H), 8.75 (s, 1H, CH=N). C NMR
(125 MHz, DMSO-d6) ꢁ: 33.71, 52.06, 60.31, 128.29, 128.32,
128.33, 128.38, 128.66, 128.66, 129.58, 129.75, 129.97, 130.65,
130.76, 130.97, 131.15, 134.57, 134.73, 140.63, 149.74, 152.48,
155.08, 158.57, 163.56. ESI-HRMS calcd. for C H Cl N O S
3
3
2
(d, ꢂ = 6.9 Hz, 1H, Ar-H), 7.30–7.54 (m, 6H, Ar-H) 7.66 (d,
ꢂ = 7.6 Hz, 2H, Ar-H), 7.82 (d, ꢂ = 4.8 Hz, 2H, Ar-H), 7.89
(d, ꢂ = 7.7 Hz, 2H, Ar-H), 8.75 (s, 1H, CH=N). 13C NMR
(125 MHz, DMSO-d6) ꢁ: 33.44. 52.97, 61.75, 126.74, 128.09,
128.28, 129.07, 129.30, 129.89, 130.01, 130.52, 130.68, 130.96,
131.17, 135.09, 138.63, 146.80, 149.10, 151.63, 158.01, 159.56,
26 22
2
5
3
+
[M + H] 554.08149; found: 554.08121.
2.7. Antimicrobial Activity Assessment. Inhibitive, active
freshly prepared compounds were tested by mycelium growth
rate method under the laboratory conditions, and these
strobilurin derivatives were screened for antifungal activity
against Rhizoctonia solani, Botrytis cinerea Pers., Fusarium
graminearum, Cotton rhizoctoniosis, and Blumeria graminis
at dosages of 50 ꢀg mL−1. Antifungal activity was determined
by measuring the diameter of the inhibition zone. e
growth inhibition rates were calculated by using the following
equation: ꢃ = [(ꢄ − ꢅ)/ꢄ] × 100%. Here, ꢃ is the growth
inhibition rate (%), ꢄ is the control settlement radius (mm),
and ꢅ is the treatment group fungi settlement radius (mm).
Activity of each compound was compared to kresoxim-
methyl as standard. e results of preliminary screening are
listed in Table 1.
+
163.69. ESI-HRMS calcd. for C H ClN O S [M + H]
26 23
5
3
520.12046; found: 520.11952.
(E)-Methyl-2-(2-(((4-((E)-(2,4-dichlorobenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6m). Pale yellow solid, yield: 71.6%, m.p.:
142-143∘C. IR (KBr, cm−1): 3099, 2967, 1646, 1609, 1561, 1514,
1
1488, 1278. H NMR (600 MHz, DMSO-d6) ꢁ: 3.68 (s, 3H,
COOCH ), 3.92 (s, 3H, =N-OCH ), 4.33 (s, 2H, CH ), 7.17 (d,
3
3
2
ꢂ = 7.4 Hz, 1H, Ar-H), 7.32–7.38 (m, 2H, Ar-H), 7.49–7.59 (m,
4H, Ar-H), 7.63 (d, ꢂ = 8.5 Hz, 1H, Ar-H), 7.80 (d, ꢂ = 4.4 Hz,
2H, Ar-H), 7.86 (s, 1H, Ar-H), 8.03 (d, ꢂ = 8.5 Hz, 1H, Ar-H),
8.90 (s, 1H, CH=N). 13C NMR (125 MHz, DMSO-d6) ꢁ:
33.72, 52.08, 60.30, 128.29, 128.34, 128.36, 128.38, 128.66,
128.68, 129.58, 129.75, 129.96, 130.65, 130.77, 130.97, 131.14,
134.57, 134.72, 140.63, 149.75, 152.48, 155.09, 158.57, 163.57.
+
3. Results and Discussion
ESI-HRMS calcd. for C H C N O S [M + H] 554.08149;
26 22 ꢀ2
5
3
found: 554.08127.
3.1. Synthetic Chemistry. Scheme 1 shows the schematic rep-
resentation of the synthetic route for the preparation of target
compounds. Compound 2 was prepared by the reaction
between ethyl benzoate 1 and 85% hydrazine hydrate in
ethanol at room temperature in excellent yield (90.6%).
Further, compound 2 was heated with carbon disulfide in
(E)-Methyl-2-(2-(((4-((E)-(3,4-dichlorobenzylidene)amino)-5-
phenyl-4H-1,2,4-triazol-3-yl)thio)methyl)phenyl)-2-(methox-
yimino)acetate (6n). Pale yellow solid, yield: 74.6%, m.p.:
101-102∘C. IR (KBr, cm−1): 3111, 2957, 1655, 1601, 1547, 1530,

Journal of Chemistry
7
O
O
O
S
N2H4 · H2O
CS2, KOH
N2H4 · H2O
C6H5
O
NHNH2
S−K+
NHNH
C6H5
C6H5
1
2
3
O
O
N
O
O
N
N
NH
R
N
NH
O
O
Br
N
N
RCHO
S
C6H5
C6H5
S
N
N
N
S
N
NH2
N
R
4
5ꢀ ꢁ 5n
6ꢀ ꢁ 6n
Scheme 1: Synthetic route of target compounds 6a–6n. R =: 6a. C H ; 6b. 4-CH C H ; 6c. 4-N(CH ) C H ; 6d. 2-OHC H ; 6e. 3-OHC H ;
6
5
3
6
4
3
2
6
4
6
4
6
4
6f. 4-OHC H ; 6g. 2-NO C H ; 6h. 3-NO C H ; 6i. 4-NO C H ; 6j. 2-ClC H ; 6k. 3-ClC H ; 6l. 4-ClC H ; 6m. 2, 4-Cl C H ; 6n. 3,4-
6
4
2
6
4
2
6
4
2
6
4
6
4
6
4
6
4
2
6
3
Cl C H .
2
6
3
the presence of absolute ethanol and potassium hydroxide to
afford intermediate potassium acylhydrazine dithioformate
3. is salt underwent ring closure with an excess of 85%
hydrazine hydrate to give intermediate 4, which was used
directly without further purification for the subsequent
reaction. Subsequently, compound 4 was allowed to react
with appropriate aromatic aldehydes and 2 to 3 drops of
glacial acetic acid to produce series of compounds 5 in
moderate yield according to the method reported in the
literature [18]. Finally, a series of the target compounds
6 were obtained by the reaction of corresponding com-
pounds 5 with (E)-methyl-2-(2-(bromomethyl)phenyl)-2-
(methoxyimino)acetate in the presence of base following
the literature method [26]. e structures of the desired
compounds were confirmed by 1H NMR, 13C NMR, IR, and
ESI-HRMS.
than that of kresoxim-methyl (65.32% against Rhizoctonia
solani, 81.69% against Botrytis cinerea Pers., and 73.36%
against Fusarium graminearum at 50 ꢀg mL−1). Moreover,
compounds 6c, 6l, and 6m exhibited 91.41, 92.13, and 91.77%
inhibitory activity against Blumeria graminis, respectively.
Interestingly, the fungicidal activities of the synthesized
compounds 6 were influenced by the position of substituted
group on the benzene ring. e sequence of fungicidal
activity against Rhizoctonia solani, Botrytis cinerea Pers.,
and Fusarium graminearum was as follows: o-substituted-
benzylidene derivatives > m-substituted-benzylidene deriva-
tives > p-substituted- benzylidene derivatives. Surprisingly,
for the p-substituted benzylidene, the fungicidal activity
against Blumeria graminis was significantly enhanced.
4. Conclusion
3.2. Biological Evaluation. e fungicidal activities of the
series of title compounds 6 were tested at a concentration of
50 ꢀg mL−1 by a modified method described in the literature
[27]. e five fungi used in the fungicidal bioassay, Rhizoc-
tonia solani, Botrytis cinerea Pers., Fusarium graminearum,
Cotton rhizoctoniosis, and Blumeria graminis, were tested by
mycelium growth rate method. e commercial agricultural
fungicide kresoxim-methyl was used as a standard.e results
of preliminary bioassays are listed in Table 1.
e values listed in Table 1 clearly indicate that all the
compounds do not exhibit good fungicidal activity against
Cotton rhizoctoniosis at the concentration of 50 ꢀg mL−1.
However, the compounds 6g and 6j exhibited promising
antifungal activity, inhibiting growth of Rhizoctonia solani
at 48.96% and 47.91%, Botrytis cinerea Pers. at 62.73% and
60.45%, and Fusarium graminearum at 60.13% and 59.54%,
respectively. However, the obtained values were still less
A series of novel (E)-ꢁ-methoxyimino-benzeneacetate deriv-
atives were synthesized. ey were characterized by IR,
1H NMR, 13C NMR, and ESI-HRMS. All the synthesized
compounds were screened for their antifungal activity by
mycelium growth rate method. e antifungal tests indicated
that compounds 6g and 6j exhibited promising antifungal
activity against Rhizoctonia solani, Botrytis cinerea Pers., and
Fusarium graminearum. Moreover, compounds 6c, 6l, and
6m exhibited higher fungicidal activities against Blumeria
graminis. erefore, this study demonstrated that methoxy-
iminoacetate derivatives containing 1,2,4-triazole Schiff base
side chain acted as promising candidates for developing
novel fungicides. is study provides an impetus to the fur-
ther exploration of antifungal compounds. Further research
involving design, synthesis, and structure optimizations is
still in progress.

8
Journal of Chemistry
Conflict of Interests
[12] A. P. Liu, X. G. Wang, X. M. Ou et al., “Synthesis and
fungicidal activities of novel bis(trifluoromethyl)phenyl- based
strobilurins,” Journal of Agricultural and Food Chemistry, vol.
56, no. 15, pp. 6562–6566, 2008.
e authors declare that there is no conflict of interests
regarding the publication of this paper.
[13] X. L. Zhu, F. Wang, H. Li, W. C. Yang, Q. Chen, and G. F.
Yang, “Design, synthesis, and bioevaluation of novel strobilurin
derivatives,” Chinese Journal of Chemistry, vol. 30, no. 9, pp.
1999–2008, 2012.
Acknowledgment
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