Synthesis and fungicidal activity of (E)-α-(Methoxyimino)benzeneacetate derivatives containing 1,2,4-triazole schiff base side Chain

Article abstract of DOI:10.1002/jhet.1795

Figure presented To find new strobilurin analogs with high activity against resistant pathogens, twelve (E)-α-(methoxyimino)benzeneacetate derivatives containing 1,2,4-triazole Schiff base side chain 3a-3l were designed and synthesized. Their structures were confirmed by IR, ¹H-NMR, EIMS, and elemental analyses. Bioassays indicated that most of the target compounds showed moderate to good fungicidal activities against Physalospora piricola Nose and Alternaria solani. For example, compounds 3d, 3e, and 3f possessed 99.5%, 100%, and 95.6% inhibition against Physalospora piricola Nose, whereas compounds 3d, 3f, and 3g exhibited 92%, 91%, and 92% inhibition against Alternaria solani at the concentration of 50 mg/L, respectively.

Full text of DOI:10.1002/jhet.1795

September 2014 Synthesis and Fungicidal Activity of (E)-a-(Methoxyimino)benzeneacetate
Derivatives Containing 1,2,4-Triazole Schiff Base Side Chain
Hong-Xing Song and De-Qing Shi*
1345
Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal
University, Wuhan 430079, Hubei, People’s Republic of China
*
E-mail: chshidq@mail.ccnu.edu.cn
Received April 22, 2012
DOI 10.1002/jhet.1795
Published online 17 March 2014 in Wiley Online Library (wileyonlinelibrary.com).
N NH
N
N
Br
S
S
F3C
N
N
K CO /CH CN
2 3 3
+
N
CF3
O
O
O
O
N
N
N
O
Ar
O
Ar
1
2
3a~3l
To find new strobilurin analogs with high activity against resistant pathogens, twelve (E)-a-(methoxyimino)
benzeneacetate derivatives containing 1,2,4-triazole Schiff base side chain 3a–3l were designed and synthe-
1
sized. Their structures were confirmed by IR, H-NMR, EIMS, and elemental analyses. Bioassays indicated that
most of the target compounds showed moderate to good fungicidal activities against Physalospora piricola
Nose and Alternaria solani. For example, compounds 3d, 3e, and 3f possessed 99.5%, 100%, and 95.6%
inhibition against Physalospora piricola Nose, whereas compounds 3d, 3f, and 3g exhibited 92%, 91%, and
92% inhibition against Alternaria solani at the concentration of 50mg/L, respectively.
J. Heterocylic Chem., 51, 1345 (2014).
INTRODUCTION
RESULTS AND DISCUSSION
Synthetic chemistry and structure characterization. The
synthetic route for the target compounds is outlined in
Scheme 1. o-Tolylmagnesium bromide reacted with oxalic
acid dimethyl ester to generate methyl oxo-o-tolyl-acetate,
which condensated with methoxyamine, followed by the
bromination of NBS to form (E)-methyl 2-(2-(bromomethyl)
phenyl)-2-methoxyiminoacetate 1 in moderate yield. 1
reacted with 4-amino-3-mercapto-5-(trifluoromethyl)-1,2,4-
triazole Schiff base 2 in the presence of potassium carbonate
in acetonitrile at RT to afford the target compounds 3 in
yields of 75–94%.
The Strobilurins are a class of fungicidal compounds
discovered after natural compounds isolated from several
basidomycete species and are used widely to agricultural
disinfectants in many countries because of their novel
mode of action, wide spectrum of antifungal activities,
and low toxicity toward mammals [1–4]. These compounds
act through inhibition of mitochondrial respiration by block-
ing electron transfer at the ubiquinol oxidation center (Qo
site) of the cytochrome bc1 complex (complex III) [5]. The
first two commercial strobilurin fungicides azoxystrobin
and kresoxim-methyl were discovered by ICI and BASF,
respectively. An (E)-methyl-b-methoxyacrylate or (E)-
methoxyiminoacetate is the common pharmacophore group
in strobilurin fungicides. However, the high frequency
repeated field application of strobilurin fungicides has led
to the development of resistance in a range of important plant
pathogens [6,7]. So, continually developing new strobilurin
fungicide analogs is the best way to solve this problem
The structures of all of the target compounds were char-
1
acterized by H-NMR, EIMS spectrum, and elemental
analyses, which were listed in the Experimental Section.
1
In the H-NMR spectra of 3, the two CH O protons
3
showed as two singlets with chemical shifts d 3.78 and
4
.0, respectively, whereas the methylene protons also
exhibited as a singlet with chemical shifts d 4.45. The
CH═N proton displayed as a singlet in d 8.35, whereas
the aromatic protons presented in d 7.2–7.8. IR spectra of
compounds 3 showed normal stretching absorption bands,
[8–11]. 1,2,4-Triazole Schiff base derivatives exhibit a broad
spectrum of biological activities such as antitumor [12,13],
herbicidal [14], antiviral [15], and fungicidal [16–18]
activities. In this study, we synthesized a series of (E)-
a-(methoxyimino)benzeneacetate derivatives containing 1,2,
À1
indicating the existence of Ar—H (~3120cm ), C═O
À1
À1
À1
(
~1730 cm ), C═N (~1610cm ), C—O—C (~1200 cm ).
The EI mass spectra of compounds 3 revealed the
existence of the weak molecular ion peaks and strong
fragment ion peaks, which were in good accordance with
the given structures of products.
Fungicidal activity. The preliminary fungicidal activity
of the target compounds 3 was evaluated by the classic
4
-triazole Schiff base side chain, via the condensation of (E)-
methyl 2-(2-(bromomethyl)phenyl)-2-methoxyiminoacetate
with 4-amino-3-mercapto-5-(trifluoromethyl)-1,2,4-
1
triazole Schiff bases 2 under basic conditions. Herein, we
would like to report the synthesis and fungicidal activities
of the title compounds 3 in this article (Scheme 1).
©
2014 HeteroCorporation

1
346
H.-X. Song and D.-Q. Shi
Vol 51
Scheme 1. Synthetic route to compounds 3a–3l.
O
CH3
°
O
-78 C
NBS/AIBN
CCl4
+
MeONH2.HCl/Pyridine
3
Br
O
MgBr
THF
O
O
CH OH, Reflux
O
O
O
O
O
N
N
O
O
O
N
NH
1
N
N
S
S
F3C
N
K CO /CH CN
2 3 3
1
+
N
N
CF3
O
O
N
N
Ar
O
2
3a~3l
Ar
plate method at the concentration of 50 mg/L, which was
described in the Experimental Section. The five fungi
Fusarium omysporum, Physalospora piricola Nose,
Alternaria solani, Cercospora arachidiaola Hori, and
Gibberella saubinetii, belong to the group of field fungi
and were isolated from corresponding crops. The
activities data were listed in Table 1. The preliminary
bioassay (in vitro) indicated that most of the target
compounds showed moderate to good fungicidal
activities against P. piricola Nose and A. solani. For
example, compounds 3d, 3e, and 3f possessed 99.5%,
relationships needs more experimental results to support.
Further biological activity (in vivo) investigations are on
the way.
In conclusion, a series of (E)-a-(methoxyimino)benze-
neacetate derivatives containing 1,2,4-triazole Schiff base
side chain 3a–3l were designed and synthesized. Their
1
structures were confirmed by IR, H-NMR, EIMS, and
elemental analyses. Bioassays indicated that most of the
target compounds showed moderate to good fungicidal
activities against P. piricola Nose and A. solani.
1
00%, and 95.6% inhibition against P. piricola Nose,
EXPERIMENTAL
whereas compounds 3d, 3f, and 3g exhibited 92%, 91%,
and 92% inhibition against A. solani at the concentration
of 50 mg/L, respectively. As for the preliminary structure-
activity relationships, firstly, most of compounds 3
showed the better fungicidal activities against P. piricola
Nose and A. solani, and P. piricola Nose is the most
effective fungus. Secondly, the electronic effects of the
phenyl substituents have influenced on their fungicidal
activities, for example, the compounds when 4-Br and
Melting points were determined with a WRS-1B digital melting
point apparatus and are uncorrected. H-NMR spectra was recorded
with a Varian Mercury PLUS 400 (400 MHz) or Varian Mercury
PLUS 600 (600 MHz) spectrometer with TMS as the internal
1
reference and CDCl as the solvent, whereas mass spectra were
3
obtained with a Finnigan TRACEMS2000 spectrometer using the
EI method. IR spectra were measured by a Nicolet NEXUS470
spectrometer. Elemental analyses were performed with an
Elementar Vario ELШ CHNSO elemental analyzer. (E)-Methyl
-(2-(bromomethyl)phenyl)-2-methoxyiminoacetate 1 and 4-amino-
-mercapto-5-(trifluoromethyl)-1,2,4-triazole Schiff base 2 were
prepared according to the literature procedure [8,19,15], respectively.
All of the solvents and materials were reagent grade and purified
as required.
2
3
4
-NO substituted on the phenyl ring such as 3d and 3e
2
showed higher activity among all the target compounds,
whereas the ortho-position substituted compounds displayed
weaker activities. Further exploring of structure-activity
Table 1
Fungicidal activity of compounds 3a–3l (in vitro, 50 mg/L, relative inhibitory rate %).
Fusarium
omysporum
Physalospora piricola
Nose
Alternaria
solani
Cercospora arachidiaola
Hori
Gibberella
saubinetii
Compd.
3
3
3
3
3
3
3
3
3
3
3
3
a
b
c
d
e
f
g
h
i
64.5
47.6
67.8
67.8
78.6
72.0
64.5
72.0
47.6
0
92.0
82.0
91.6
99.5
100
95.6
91.6
95.0
78.6
88.5
72.0
90.8
98.5
85.0
58.5
82.6
92.0
82.6
91.0
92.0
76.0
58.5
58.5
58.5
70.2
92.4
68.4
58.0
68.4
75.5
75.5
75.5
68.4
63.0
48.5
48.5
58.0
48.5
98.5
76.5
50.5
83.5
91.2
82.0
76.5
63.0
63.0
56.8
56.8
53.6
65.5
96.8
j
k
l
64.5
64.5
100
kresoxim-methyl
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

September 2014
(E)-a-(Methoxyimino)benzeneacetate Derivatives
1347
Containing 1,2,4-Triazole Schiff Base Side Chain
General procedure for the synthesis of 3.
mercapto-5-(trifluoromethyl)-1,2,4-triazole Schiff base 2 (1 mmol), (E)-
methyl 2-(2-(bromomethyl)phenyl)-2-methoxyiminoacetate 1
4-Amino-3-
7.55 (t, J= 4.2 Hz, 1H, ArH), 7.70 (d, J= 8.4 Hz, 2H, ArH), 8.34 (s,
1H, ═CH); IR (KBr) υ: 3126 (ArH), 1734 (C═O), 1604 (C═N),
1122, 1068 (C—O—C) cm ; EIMS m/z (%): 491 (M , 1.2), 460 (3),
À1
+
(
0.32 g, 1.1 mmol), K
2
CO
3
(0.21 g, 1.5 mmol), and anhydrous
258 (4.8), 206 (34), 205 (100), 175 (9.5), 146 (36), 116 (51),
acetonitrile (10 mL) were added to a 50mL three-necked flask.
The reaction mixture was stirred at RT and monitored by TLC. At
completion of the reaction (about 4 h), the workup involved addition
of water (30 mL) and extraction of the product mixture into
chloroform (15 mL Â 3), after phase separation, drying over
anhydrous sodium sulfate, filtration, and evaporation, the crude
product was followed by chromatography purification on silica using
a mixture of petroleum ether and ethyl acetate (3:1) as an eluent to
91 (36), 89 (18), 59 (20). Anal. Calcd for C22
53.76, H 4.10, N 14.25; found C 53.90, H 4.03, N 14.37.
g (Ar = H;4-CH O-C ). White solid, yield: 94%, mp 88.4–
89.6 C; H-NMR (CDCl , 400 MHz) d: 3.78 (s, 3H, OCH ), 3.89
20 3 5 3
H F N O S: C
3
3
6 4
H
ꢀ
1
3
3
(s, 3H, CH O), 4.02 (s, 3H, OCH ), 4.44 (s, 2H, CH ), 6.99
3
3
2
(d, J= 7.6 Hz, 2H, ArH), 7.14 (t, J= 7.8 Hz, 1H, ArH), 7.37
(t, J= 6.6 Hz, 2H, ArH), 7.55 (t, J= 5.4 Hz, 1H, ArH), 7.77 (d,
J= 7.6 Hz, 2H, ArH), 8.27 (s, 1H, ═CH); IR (KBr) υ: 3125 (ArH),
À1
give the target compounds in 75–94% yields.
1738 (C═O), 1601 (C═N), 1121, 1064 (C—O—C) cm ; EIMS
ꢀ
+
3
a (Ar = H;C H ). White solid, yield: 84%, mp 78.4–80.1 C;
m/z (%): 507 (M , 1.6), 206 (37), 205 (100), 146 (41), 116 (65), 95
6
5
1
H-NMR (CDCl
3
, 400 MHz) d: 3.77 (s, 3H, CH
), 7.15 (t, J= 6.0 Hz, 1H, ArH), 7.36–7.38
m, 2H, ArH), 7.48–7.60 (m, 4H, ArH), 7.81 (t, J = 7.2 Hz, 2H,
3
O), 4.02 (s, 3H,
(25), 89 (20), 59 (25). Anal. Calcd for C22
3.97, N 13.80; found C 52.16, H 3.82, N 13.64.
3h (Ar = H;3-Cl-C H ). White solid, yield: 83%, mp 113.8–
20 3 5 4
H F N O S: C 52.07, H
3 2
OCH ), 4.46 (s, 2H, CH
(
6
4
ꢀ
1
ArH), 8.39 (s, 1H, ═CH); IR (KBr) υ: 3130 (ArH), 1728 (C═O),
1
15.4 C; H-NMR (CDCl
3
, 400 MHz) d: 3.81 (s, 3H, OCH
3
), 4.03
À1
1
(
(
600 (C═N), 1137, 1068(C—O—C) cm ; EIMS m/z (%): 477
(
s, 3H, OCH ), 4.46 (s, 2H, CH
3
2
), 7.16 (q, J= 7.8 Hz, 1H, ArH),
+
M , 1.0), 446 (3.3), 205 (100), 175 (9.8), 146 (42), 116 (58), 89
25), 77 (34). Anal. Calcd for C21 S: C 52.83, H 3.80, N
7.38 (q, J= 7.2 Hz, 2H, ArH), 7.45 (t, J= 8.0 Hz, 1H, ArH), 7.54
(q, J= 7.6 Hz, 2H, ArH), 7.68 (d, J= 7.6 Hz, 1H, ArH), 7.81 (s, 1H,
ArH), 8.36 (s, 1H, ═CH); IR (KBr) υ: 3120 (ArH), 1735 (C═O),
18 3 5 3
H F N O
1
4.67; found C 52.64, H 3.97, N 14.61.
b (Ar= H;4-F-C ). White solid, yield: 82%, mp 129.4–
30.7 C; H-NMR (CDCl , 600 MHz) d: 3.78 (s, 3H, CH O), 4.02
À1
3
6
H
4
1605 (C═N), 1128, 1061 (C—O—C) cm ; EIMS m/z (%): 511
ꢀ
1
+
1
3
3
(M , 1.1), 258 (3.5), 206 (38), 205 (100), 175 (8.3), 146 (42), 116
(
s, 3H, OCH ), 4.45 (s, 2H, CH ), 7.15 (t, J= 6.0 Hz, 1H, ArH),
(62), 89 (32), 59 (24), 44 (32). Anal. Calcd for C H ClF N O S:
3
2
21 17
3 5 3
7.19 (t, J= 8.4 Hz, 2H, ArH), 7.37 (t, J= 6.6 Hz, 2H, ArH), 7.53
C 49.27, H 3.35, N 13.68; found C 49.13, H 3.29, N 13.50.
(
8
t, J= 6.0 Hz, 1H, ArH), 7.83 (dd, J=5.4Hz, J= 9.0 Hz, 2H, ArH),
3i (Ar = H;3-NO -C H ). White solid, yield: 91%, mp 129.3–
2
6 4
ꢀ
130.9 C; H-NMR (CDCl , 400 MHz) d: 3.83 (s, 3H, CH O),
3 3
1
.35 (s, 1H, ═CH); IR (KBr) υ: 3125 (ArH), 1732 (C═O), 1602
À1
+
(C═N), 1125, 1065(C—O—C) cm ; EIMS m/z (%): 495 (M ,
4.04 (s, 3H, OCH ), 4.47 (s, 2H, CH ), 7.16 (d, J = 7.6 Hz, 1H,
3 2
1
9
5
.1), 464 (3.0), 206 (37), 205 (100), 175 (12), 146 (44), 116 (67),
ArH), 7.39 (q, J = 7.6 Hz, 2H, ArH), 7.51 (d, J = 7.6 Hz, 1H,
ArH), 7.73 (t, J = 7.2 Hz, 1H, ArH), 8.20 (d, J = 7.6 Hz, 1H,
ArH), 8.44 (d, J = 7.6 Hz, 1H, ArH), 8.49 (s, 1H, ArH), 8.36 (s,
1H, ═CH); IR (KBr) υ: 3124 (ArH), 1736 (C═O), 1618
5 (26), 89 (21), 59 (26). Anal. Calcd for C H F N O S: C
21 17 4 5 3
0.91, H 3.46, N 14.14; found C 51.07, H 3.39, N 14.20.
c (Ar = H;4-Cl-C H ). White solid, yield: 76%, mp 121.1–
3
6
4
ꢀ
1
À1
1
4
21.1 C; H-NMR (CDCl
3
, 400 MHz) d: 3.79 (s, 3H, CH
3
O),
(C═N), 1122, 1063 (C—O—C) cm ; EIMS m/z (%): 522
+
.03 (s, 3H, OCH ), 4.46 (s, 2H, CH
3
2
), 7.15 (t, J = 7.2 Hz, 1H,
(M , 1), 491 (2), 206 (52), 205 (100), 146 (46), 116 (75), 89
ArH), 7.37 (t, J = 6.0 Hz, 2H, ArH), 7.50 (d, J = 7.6 Hz, 2H,
ArH), 7.53 (d, J = 7.2 Hz, 1H, ArH), 7.76 (d, J = 8.0 Hz, 2H,
(27), 76 (15), 59 (27). Anal. Calcd for C21
48.28, H 3.28, N 16.09; found C 48.34, H 3.41, N 16.13.
j (Ar = H;2-F-C ). White solid, yield: 78%, mp 136.4–
137.3 C; H-NMR (CDCl , 400 MHz) d: 3.83 (s, 3H, CH O),
17 3 6 5
H F N O S: C
ArH), 8.36 (s, 1H, ═CH); IR (KBr) υ: 3128 (ArH), 1735
3
6 4
H
À1
1
ꢀ
(
C═O), 1605 (C═N), 1123, 1068 (C—O—C) cm . Anal.
3
3
Calcd for C21
C 49.14, H 3.30, N 13.49.
d (Ar = H;4-Br-C H ). White solid, yield: 85%, mp 127.0–
H
17ClF
3
N
5
O
3
S: C 49.27, H 3.35, N 13.68; found
4.04 (s, 3H, OCH ), 4.49 (s, 2H, CH ), 7.16–7.21 (m, 2H, ArH),
3 2
7.30 (d, J = 7.6 Hz, 1H, ArH), 7.38 (t, J = 6.6 Hz, 2H, ArH), 7.59
(t, J = 8.4 Hz, 2H, ArH), 8.06 (t, J = 7.2 Hz, 1H, ArH), 8.77 (s, 1H,
═CH); IR (KBr) υ: 3127 (ArH), 1705 (C═O), 1612 (C═N),
3
6
4
ꢀ
1
1
4
28.6 C; H-NMR (CDCl , 400MHz) d: 3.79 (s, 3H, CH O),
3
3
À1
+
3 2
.03 (s, 3H, OCH ), 4.46 (s, 2H, CH ), 7.15 (q, J = 7.2 Hz, 1H,
1173, 1068 (C—O—C) cm ; EIMS m/z (%): 495 (M , 2), 464
ArH), 7.37 (q, J = 7.6 Hz, 2H, ArH), 7.54 (t, J = 7.2 Hz, 1H, ArH),
(4), 206 (40), 205 (100), 146 (43), 116 (55), 95 (12), 89 (20), 59
7
.64–7.70 (m, 4H, ArH), 8.35 (s, 1H, ═CH); IR (KBr) υ: 3134
(21). Anal. Calcd for C21
found C 50.84, H 3.33, N 14.20.
3k (Ar = H;2-Br-C H ). White solid, yield: 75%, mp 144.4–
H F N O S: C 50.91, H 3.46, N 14.14;
17 4 5 3
À1
(
ArH), 1738 (C═O), 1612 (C═N), 1120, 1064 (C—O—C) cm
.
Anal. Calcd for C21
found C 45.47, H 3.01, N 12.71.
3 5 3
H17BrF N O S: C 45.34, H 3.08, N 12.59;
6
4
ꢀ
145.2 C; H-NMR (CDCl , 400 MHz) d: 3.84 (s, 3H, CH O),
3 3
1
3
e (Ar= H;4-NO -C H ). White solid, yield: 82%, mp 198.7–
4.05 (s, 3H, OCH ), 4.52 (s, 2H, CH ), 7.16 (q, J = 7.6 Hz, 1H,
2
6
4
3 2
ꢀ
1
2
4
7
7
00.6 C; H-NMR (CDCl
.03 (s, 3H, OCH ), 4.46 (s, 2H, CH
.36–7.39 (m, 2H, ArH), 7.52–7.55 (m, J = 8.4 Hz, 2H, ArH),
.63–7.70 (m, 2H, ArH), 8.36 (s, 1H, ═CH); IR (KBr) υ: 3125
3
, 400MHz) d: 3.79 (s, 3H, CH
3
O),
ArH), 7.37 (q, J = 7.6 Hz, 2H, ArH), 7.45 (q, J = 6.0 Hz, 2H,
ArH), 7.61 (t, J = 7.2 Hz, 1H, ArH), 7.67 (t, J = 8.4 Hz, 1H,
ArH), 8.12 (t, J = 8.4 Hz, 1H, ArH), 8.96 (s, 1H, ═CH); IR
(KBr) υ: 3122 (ArH), 1726 (C═O), 1609 (C═N), 1175, 1072
3
2
), 7.14–7.16 (m, 2H, ArH),
À1
À1
(
ArH), 1731 (C═O), 1615 (C═N), 1123, 1059 (C—O—C) cm
.
(C—O—C) cm . Anal. Calcd for C H BrF N O S: C
2
1
17
3 5 3
17 3 6 5
Anal. Calcd for C21H F N O S: C 48.28, H 3.28, N 16.09; found
45.34, H 3.08, N 12.59; found C 45.47, H 3.11, N 12.73.
C 48.11, H 3.24, N 16.23.
f (Ar= H;4-CH -C
1.2 C; H-NMR (CDCl
H, CH O), 4.01 (s, 3H, OCH
H, ArH), 7.30 (d, J= 7.8 Hz, 2H, ArH), 7.36 (t, J= 4.2 Hz, 2H, ArH),
3l (Ar = H;2-CH O-C H ). White solid, yield: 87%, mp 87.0–
3
6
4
ꢀ
1
3
3
6
H
3
4
). White solid, yield: 82%, mp 89.0–
, 600MHz) d: 2.44 (s, 3H, CH ), 3.78 (s,
), 4.45 (s, 2H, CH ), 7.14 (t, J=4.8Hz,
88.1 C; H-NMR (CDCl
3 3
3.89 (s, 3H, CH O), 4.03 (s, 3H, OCH ), 4.47 (s, 2H, CH
3
, 400 MHz) d: 3.81 (s, 3H, OCH
3
),
),
ꢀ
1
9
3
1
3
2
3
3
2
6.97 (d, J = 8.0 Hz, 1H, ArH), 7.05 (t, J = 7.6 Hz, 1H, ArH),
7.14 (t, J = 6.8 Hz, 1H, ArH), 7.36 (t, J = 8.0 Hz, 2H, ArH), 7.53–
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

1
348
H.-X. Song and D.-Q. Shi
Vol 51
7
═
1
.61 (m, 2H, ArH), 8.03 (d, J = 7.6 Hz, 1H, ArH), 8.90 (s, 1H,
CH); IR (KBr) υ: 3127(ArH), 1731 (C═O), 1598 (C═N),
148, 1070 (C—O—C) cm ; EIMS m/z (%): 507 (M , 1), 476
[2] Sauter, H.; Steglich, W.; Anke, T. Angew Chem Int Ed 1999,
8, 1328 and references therein.
3
À1
+
[3] Bartett, D. W.; Clough, J. M.; Godfrey, C. R. A.; Godwin,
J. R.; Hall, A. A.; Heaney, S. P.; Maund, S. J. Pestic Outlook 2001,
2, 143.
4] Bartlett, D. W.; Clough, J. M.; Godwin, J. R.; Hall, A. A.;
(
2), 258 (4), 206 (29), 205 (100), 146 (32), 116 (45), 91 (21),
1
8
5
9 (18), 77 (27), 59 (20). Anal. Calcd for C22
2.07, H 3.97, N 13.80; found C 52.03, H 3.84, N 13.95.
Fungicidal activity testing. The fungicidal activity measurement
method was adapted from the one described by Molina Torres
20]. The synthesized target compounds were dissolved in
.5–1.0 mL of DMF to the concentration of 500 mg/L. The
20 3 5 4
H F N O S: C
[
Hamer, M.; Parr-Dobrzanski, B. Pest Manag Sci 2002, 58, 649.
[5] Becker, W. F.; von Jagow, G.; Anke, T.; Steglich, W. FEBS
Lett 1981, 132, 329.
[
[
6] Fisher, N.; Meunier, B. Pest Manag Sci 2005, 61, 973.
7] Gisi, U.; Sierotzki, H.; Cook, A.; McCaffery, A. Pest Manag
[
0
Sci 2002, 58, 859.
solutions (1 mL) were mixed rapidly with thawed potato
glucose agar culture medium (9 mL) under 50 C. The mixtures
were poured into Petri dishes. After the dished were cooled, the
[8] Huang, W.; Zhao, P. L.; Liu, C.-L.; Chen, Q.; Liu, Z.-M.;
ꢀ
Yang, G.-F. J Agric Food Chem 2007, 55, 3004.
[9] Li, M.; Liu, C.-L.; Yang, J.-C.; Zhang, J.-B.; Li, Z.-N.; Zhang,
solidified plates were incubated with 4 mm mycelium disk,
inverted, and incubated at 28 C for 48h. Distilled water was used
H.; Li, Z.-M. J Agric Food Chem 2010, 58, 2664.
[10] Tu, S.; Xu, L.-H.; Ye, L.-Y.; Wang, X.; Sha, Y.; Xiao, Z.-Y. J
Agric Food Chem 2008, 56, 5247.
ꢀ
as the blank control and the commercial available fungicide
kresoxim-methyl as the control drug. Three replicates of each test
were carried out. The mycelial elongation radius (mm) of fungi
settlements was measured after 48 h of culture. The growth
inhibitory rates were calculated with the following equation:
I=[(CÀ T)/C]Â 100%. Here, I is the growth inhibitory rate (%), T
is the treatment group fungi settlement radius (mm), and C is the
radius of the blank control. The results are listed in Table 1.
[
11] Li, Y.; Zhang, H.-Q.; Liu, J.; Yang, X.-P.; Liu, Z.-J. J Agric
Food Chem 2006, 54, 3636.
12] Yang, R. S.; Hu, G. Q.; Xie, S. Q.; Huang, W. L. Chin J Appl
Chem 2008, 25, 783.
13] Hu, G. Q.; Hou, L. L.; Xie, S. Q.; Du, G. J.; Huang, W. L.;
[
[
Zhang, H. B. Chin J Org Chem 2008, 28, 700.
[14] Chai, A.; Xue, S. J.; Bian, W. D.; Yu, S. R. Chin J Org Chem
2008, 28, 1199.
[15] Li, Q. Z.; Song, B. A.; Cai, X. J.; Zheng, Y. G.; Guo, Q. Q.
Chin J Org Chem 2010, 30, 569.
Acknowledgments. This work was supported by the Natural
Science Foundation of China (Grant No. 20872046) and the
Fundamental Research Funds for the Central Universities
[16] Zhao, P. L.; Zhang, B.; Wang, Y. Z.; Yang, G. F. Chin J Org
Chem 2008, 28, 875.
[
17] Hu, G. Q.; Yao, S. M.; Li, S.; Du, G. J.; Huang, W. L.; Zhang,
H. B. Chin J Org Chem 2007, 27, 636.
18] Yuan, Z. L.; Wu, Q.; Yang, X. B.; Hu, Q. H.; Zhang, M. Q.
(
No. CCNU09A02013).
[
Chin J Org Chem 2011, 31, 1698.
REFERENCES AND NOTES
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1] Beautement, K.; Clough, J. M.; De Fraine, P. J.; Godfrey, C.
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Journal of Heterocyclic Chemistry
DOI 10.1002/jhet