Design, synthesis, and biological activities of novel 2-cyanoacrylates containing oxazole, oxadiazole, or quinoline moieties

Article abstract of DOI:10.1021/jf803632t

A series of novel 2-cyanoacrylates containing an oxazole, oxadiazole, or quinoline moiety were designed and synthesized, and their structures were characterized by ¹H NMR and elemental analysis (or high-resolution mass spectrometry). Their herbicidal activities against four weeds were evaluated, and the result indicated that some of the title compounds showed excellent herbicidal activities against rape and amaranth pigweed in postemergence treatment at a dose of 375 g/ha. Furthermore, most of these cyanoacrylates exhibited interesting plant growth regulatory activities.

Full text of DOI:10.1021/jf803632t

J. Agric. Food Chem. 2009, 57, 2849–2855 2849
Design, Synthesis, and Biological Activities of Novel
2-Cyanoacrylates Containing Oxazole, Oxadiazole, or
Quinoline Moieties
QIQI ZHAO, SHAOHUA LIU, YONGHONG LI, AND QINGMIN WANG*
State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic
Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
A series of novel 2-cyanoacrylates containing an oxazole, oxadiazole, or quinoline moiety were
designed and synthesized, and their structures were characterized by 1H NMR and elemental analysis
(or high-resolution mass spectrometry). Their herbicidal activities against four weeds were evaluated,
and the result indicated that some of the title compounds showed excellent herbicidal activities against
rape and amaranth pigweed in postemergence treatment at a dose of 375 g/ha. Furthermore, most
of these cyanoacrylates exhibited interesting plant growth regulatory activities.
KEYWORDS: Cyanoacrylates; oxazole; oxadiazole; quinoline; herbicidal activity; plant growth regulatory
activity
INTRODUCTION
designed a series of new 2-cyanoacrylates (D) bearing an
oxazole, oxadiazole, or quinoline group, in which R2 was chosen
as methylthio, isopropyl, or ethyl and R3 was fixed as an
ethoxyethyl group according to the structure-activity relation-
ship. Herein, we report the synthesis of these new 2-cyanoacry-
lates (D) bearing an oxazole, oxadiazole, or quinoline group.
The target compounds were evaluated for herbicidal activity
and plant growth regulatory activity.
2-Cyanoacrylates A are inhibitors of photosystem II (PSII)
electron transport that disrupt photosynthetic electron transport
at the PSII reaction center so as to inhibit the growth of weeds.
Among these cyanoacrylates, some compounds have been
reported to exhibit high inhibitory activity of the Hill reaction
and good herbicidal activities (1-5). Furthermore, 2-cyanoacry-
lates have also been reported to show fungicidal (6, 7) and
antiviral (8-11) activities.
MATERIALS AND METHODS
Bioisosterism is an effective way to optimize bioactive
compounds, and there are many successful examples such as
nitenpyram, acetamiprid, and thiacloprid (12, 13). In previous
works, we have reported the syntheses of cyanoacrylates
containing a heterocycle such as pyridine (B) and thiazole (C)
groups, and some of these compounds exhibited notable
activities (14-16).
The binding model of cyanoacrylate PSII electron transport
inhibitor B with the D1 protein of PSII was built, and the
structure-activity relationship research by comparative molec-
ular field analysis (CoMFA) was reported in our previous
work (4, 17). We have found that the N atom on the pyridine
ring could form an H-bond with the backbone amide of Phe265
on the D1 protein. At the same time, a bulky and electronegative
group around the para-position of the aromatic rings would have
the potential for higher activity. Moreover, the structure-activity
relationship also indicated that the activity of A could be
enhanced by decreasing the size of R2.
1
Instruments. H NMR spectra were obtained at 300 MHz using a
Bruker AV300 spectrometer or at 400 MHz using a Varian Mercury
Plus400 spectrometer in CDCl3 solution with tetramethylsilane as the
internal standard. Chemical shift values (δ) were given in ppm.
Elemental analyses were determined on a Yanaca CHN Corder MT-3
elemental analyzer. High-resolution mass spectrometry (HRMS) data
were obtained on a FTICR-MS instrument (Ionspec 7.0T). The melting
points were determined on an X-4 binocular microscope melting point
apparatus (Beijing Tech Instruments Co., Beijing, China) and were
uncorrected. Yields were not optimized.
General Synthesis. Different aminomethyl-substituted oxazoles,
oxadizoles, and quinolines were synthesized via the corresponding
halomethyl compounds by the Gabriel reaction, which involved
alkylation of potassium phthalimide followed by cleavage of the
phthaloyl protecting group (5, 16, 18).
Compounds IVa, IVb, and IVc were prepared according to our previous
work (14, 15). All of the anhydrous solvents were dried and distilled by
standard techniques. The heterocycles were listed in Table 1.
General Synthetic Procedures for I1 and I2. A mixture of 1 (12.4
mmol) and 1,3-dichloroacetone (3.15 g, 24.8 mmol) was heated at 130
°C for 1 h. After the mixture was cooled to room temperature, water
(30 mL) was added, and the mixture was extracted with dichlo-
romethane (3 × 15 mL). The organic layer was dried over anhydrous
magnesium sulfate, filtered, and concentrated in vacuo, and then, the
crude product was recrystallized with petroleum ether (60-90 °C) and
ethyl acetate to give a white solid.
It is known that nitrogen-containing heterocycles such as
oxazole, oxadiazole, or quinoline often appear as bioisosteric
analogues of benzene, pyridine, and thiazole. Hence, we have
* To whom correspondence should be addressed. Tel: +86(0)22-
23499842. Fax: +86(0)22-23499842. E-mail: wang98h@263.net.
10.1021/jf803632t CCC: $40.75  2009 American Chemical Society
Published on Web 03/09/2009

2850 J. Agric. Food Chem., Vol. 57, No. 7, 2009
Table 1. Type of Heterocycle Ar
Zhao et al.
Scheme 1. General Synthetic Route for Phenyl-Substituted Oxazolmeth-
ylchloride I1 and I2
Scheme 5. General Synthetic Route for Arylmethylamines III1-III9
Scheme 6. General Synthetic Route for the Title Compounds Va-Vs
Scheme 2. General Synthetic Route for Alkyl-Substituted Oxazolmeth-
ylchloride I3 and I4
Scheme 3. General Synthetic Route for 3-Phenyl-1,2,4-oxadiazole-5-
methylchloride I5 and I6
Table 2. Title Compounds Va-Vsa
compound
Ar
R
compound
Ar
R
Va
Vb
Vc
Vd
Ve
Vf
Vg
Vh
Vi
1
1
2
2
4
3
3
5
5
6
SMe
i-Pr
SMe
i-Pr
SMe
SMe
i-Pr
SMe
i-Pr
Vk
Vl
6
6
7
7
7
9
9
8
8
i-Pr
Et
SMe
Et
i-Pr
SMe
i-Pr
i-Pr
SMe
Vm
Vn
Vo
Vp
Vq
Vr
Vs
Vj
SMe
a Note: The meanings of the number in the Ar column were identical with those
Scheme 4. General Synthetic Route for Quinolinylmethylbromide I7, I8,
and I9
of intermediates I, II, and III in Table 1.
General Synthetic Procedures for 3a and 3b. To a cooled solution
(below 0 °C) of diazomethane in ethyl ether was added dropwise a
solution of isoburyryl chloride or acetyl chloride (20 mmol) in ethyl
ether (10 mL). The mixture was stirred below 0 °C for 24 h, and then,
nitrogen gas was guided in to remove the remaining diazomethane.
The solution was dried over anhydrous magnesium sulfate, filtered,
and concentrated in vacuo to give the crude product as a yellow oil
(3), which was utilized in the next step without further purification.
Data for 3a. Yield, 99.2%. 1H NMR (CDCl3): δ 1.08 [d, 3JHH ) 6.8
Hz, 6H, (CH3)2CH], 2.27 [m, 1H, (CH3)2CH], 5.27 (s, 1H, CHdN).
Data for 3b. Yield, 98.1%. 1H NMR (CDCl3): δ 2.01 (s, 3H, CH3),
5.26 (s, 1H, CH).
1
Data for I1. Yield, 70.1%; mp, 53-55 °C. H NMR (CDCl3): δ
4.56 (s, 2H, CH2), 7.43-7.45 (m, 3H, Ar-H), 7.68 (s, 1H, Ar-H),
8.01-8.04 (m, 2H, Ar-H).
1
Data for I2. Yield, 79.3%; mp, 93- 95 °C. H NMR (CDCl3): δ
4.57 (s, 2H, CH2), 7.37-7.44 (m, 2H, Ar-H), 7.72 (s, 1H, Ar-H),
General Synthetic Procedures for I3 and I4. To a cooled (-15
°C) flask containing chloroacetonitrile (15 mL) was added boron
3
7.92 (d, JHH ) 7.6 Hz, 1H, Ar-H), 8.04 (s, 1H, Ar-H).

Novel 2-Cyanoacrylates
J. Agric. Food Chem., Vol. 57, No. 7, 2009 2851
Table 3. Herbicidal Activities of Compounds Va-Vs (1.5 kg/ha, Percent Inhibition)
postemergence treatment
preemergence treatment
compound
rape
amaranth pigweed
alfalfa
hairy crabgrass
rape
amaranth pigweed
alfalfa
hairy crabgrass
Va
Vb
Vc
Vd
Ve
Vf
Vg
Vh
Vi
Vj
Vk
Vl
Vm
Vn
Vo
Vp
Vq
Vr
34.7
87.3
25.4
80.5
10.0
5.0
100
100
100
15.0
100
0
0
71.4
0
84.1
100
26.8
80.5
0
100
0
100
0
0
0
0
0
0
0
15.0
0
43.2
0
10.0
0
15.0
0
0
0
10.0
0
0
5.0
0
0
15.0
0
10.0
52.7
0
48.4
10.0
88.0
15.0
0
0
0
10.0
0
18.2
74.9
5.0
10.0
0
5.0
0
10.0
5.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5.0
0
0
0
0
0
0
10.0
0
0
0
0
0
0
10.0
0
0
0
87.0
6.5
0
10.0
0
10.0
37.5
57.5
10.0
82.5
0
0
43.9
5.0
0
0
50.3
0
0
0
0
20.0
0
35.6
8.5
0
0
0
0
72.0
100
73.7
100
100
77.8
100
0
100
100
50.6
66.2
0
45.5
48.1
0
0
41.9
35.5
0
10.0
Vs
67.8
Table 4. Herbicidal Activities of Compounds V (Postemergence Treatment,
Percent Inhibition)
with water (2 × 10 mL), dried over anhydrous magnesium sulfate,
filtered, and concentrated in vacuo. The residue was purified by flash
chromatography on a silica gel [eluent, ethyl acetate/petroleum ether
(60- 90 °C), 1:2, v/v] to afford a white solid.
compound
dose (g/ha)
rape
amaranth pigweed
750
375
750
375
750
375
750
375
57.4
35.4
100
99.5
100
87.2
100
100
Data for 6a. Yield, 54.7%; mp, 126- 128 °C. 1H NMR (CDCl3): δ
Vg
Vp
Vr
3
4.32 (s, 2H, CH2), 5.31 (brs, 2H, NH2), 7.69 (d, JHH ) 8.4 Hz, 2H,
3
100
96.0
100
57.6
100
91.9
Ar-H), 7.82 (d, JHH ) 8.4 Hz, 2H, Ar-H).
Data for 6b. Yield, 60.2%; mp, 134- 136 °C. 1H NMR (CDCl3): δ
3
4.32 (s, 2H, CH2), 5.13 (brs, 2H, NH2), 7.13 (t, JHH ) 8.7 Hz, 2H,
Ar-H), 7.67- 7.72 (m, 2H, Ar-H).
Vs
General Synthetic Procedures for I5 and I6. A solution of 6 in
xylene (20 mL) was refluxed for 5 h and then concentrated. The residue
was purified by flash chromatography on a silica gel [eluent, ethyl
acetate/petroleum ether (60- 90 °C), 1:10, v/v] to give I5 and I6 as a
light yellow oil.
trifluoride-ethyl ether (5- 6 mL), and then, a solution of 3 (17 mmol)
in chloroacetonitrile (10 mL) was added dropwise while the temperature
was kept at -10 °C. After it was stirred at room temperature for 1 h,
the solution was poured into a mixture of ice and ethyl ether and
modulated to alkalescence, and the aqueous layer was extracted with
ethyl ether (2 × 20 mL). The combined organic layer was dried over
anhydrous magnesium sulfate, filtered, and concentrated in vacuo to
afford yellow oil.
Data for I5. Yield, 95.1%. 1H NMR (CDCl3): δ 4.77 (s, 2H, CH2),
7.76 (d, 3JHH ) 8.0 Hz, 2H, Ar-H), 8.21 (d, 3JHH ) 8.0 Hz, 2H, Ar-H).
Data for I6. Yield, 87.0%. 1H NMR (CDCl3): δ 4.74 (s, 2H, CH2),
3
7.18 (t, JHH ) 8.8 Hz, 2H, Ar-H), 8.06-8.10 (m, 2H, Ar-H).
General Synthetic Procedures for I7, I8, and I9. A mixture of
methylquinoline (3 g, 21 mmol), N-bromosuccinimide (NBS, 3.7 g,
21 mmol), azodiisobutyronitrile (AIBN, 0.05 g), and carbon tetrachlo-
ride (100 mL) was refluxed for 2 h. After the mixture was cooled, the
precipitate was filtered off, and the filtrate was washed with brine, dried
over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The
residue was purified by flash chromatography on a silica gel [eluent,
ethyl acetate/petroleum ether (60- 90 °C), 1:9, v/v] to afford a yellow
oil, which was sent to the next step as soon as possible to avoid
polymerization.
Data for I3. Yield, 67.6%. 1H NMR (CDCl3): δ 1.25 [d, 3JHH ) 7.2
Hz, 6H, (CH3)2CH], 2.92-2.99 [m, 1H, (CH3)2CH], 4.55 (s, 2H, CH2),
6.68 (s, 1H, Ar-H).
Data for I4. Yield, 43.4%. 1H NMR (CDCl3): δ 2.31 (s, 3H, CH3),
4.54 (s, 2H, CH2), 6.70 (s, 1H, Ar-H).
General Synthetic Procedure for 5. To a stirred mixture of
hydroxylamine hydrochloride (0.69 g, 10 mmol), water (1 mL), and
sodium hydroxide (0.4 g, 10 mmol) was added dropwise substituted
benzonitrile (4, 8.54 mmol) in ethanol (7 mL). Then, the mixture was
refluxed for 18 h and cooled to room temperature. After most ethanol
was removed in vacuo, water was added and extracted with dichlo-
romethane (3 × 10 mL). The organic layer was dried over anhydrous
magnesium sulfate, filtered, and concentrated in vacuo to give a white
solid (5).
Data for I7. Yield, 41.6%. 1H NMR (CDCl3): δ 4.71 (s, 2H, CH2),
3
7.53-7.58 (m, 2H, Ar-H), 7.73 (t, JHH ) 7.2 Hz, 1H, Ar-H), 7.81
(d, 3JHH ) 8.0 Hz, 1H, Ar-H), 8.06 (d, 3JHH ) 8 0.4 Hz, 1H, Ar-H),
3
8.17 (d, JHH ) 8.4 Hz, 1H).
Data for I8. Yield, 73.4%. 1H NMR (CDCl3): δ 4.70 (s, 2H, CH2),
7.55 (t, 3JHH ) 8.0 Hz, 1H, Ar-H), 7.74 (t, 3JHH ) 8.0 Hz, 1H, Ar-H),
7.80 (d, 3JHH ) 8.0 Hz, 1H, Ar-H), 8.01 (s, 1H, Ar-H), 8.12 (d, 3JHH
Data for 5a. Yield, 70.2%; mp, 128-129 °C. 1H NMR (CDCl3): δ
4.92 (brs, 3H, NH2 and OH), 7.67 (d, 3JHH ) 8.4 Hz, 2H, Ar-H), 7.75
4
3
) 8.0 Hz, 1H, Ar-H), 8.82 (d, JHH ) 2.4 Hz, 1H).
(d, JHH ) 8.4 Hz, 2H, Ar-H).
Data for I9. Yield, 72.6%. 1H NMR (CDCl3): δ 4.66 (s, 2H, CH2),
7.41-7.45 (m, 1H, Ar-H), 7.57-7.61 (m, 1H, Ar-H), 7.66 (s, 1H,
Ar-H), 8.15 (t, 3JHH ) 7.5 Hz, 2H, Ar-H), 8.93-8.95 (m, 1H, Ar-H).
General Synthetic Procedures for II. To a solution of I (6 mmol)
in N,N-dimethylformamide (10 mL) was added potassium phthalimide
(6 mmol) in portions. After the mixture was stirred at room temperature
for 5 h, water (50 mL) was added, and the precipitate was collected by
filtration and washed with water. After recrystallization from ethanol,
a white crystal was obtained.
1
Data for 5b. Yield, 75.3%; mp, 79- 81 °C. H NMR (CDCl3): δ
4.92 (brs, 3H), 7.08 (t, 3JHH ) 8.4 Hz, 2H, Ar-H), 7.60-7.63 (m, 2H,
Ar-H).
General Synthetic Procedure for 6. To a cooled (below 0 °C)
solution of 5 (4.9 mmol) in chloroform (20 mL) was added dropwise
chloroacetyl chloride (0.55 g, 4.9 mmol) in chloroform (10 mL), and
the mixture was stirred for 20 min. Then, triethylamine (0.65 g, 6.5
mmol) in chloroform (10 mL) was added dropwise, and the solution
was stirred under room temperature for 5 h. The mixture was washed

2852 J. Agric. Food Chem., Vol. 57, No. 7, 2009
Zhao et al.
Figure 1. Chemical structures of compounds A-D.
Table 5. Plant Growth Regulatory Activities (10 mg/L) of Some of Compounds V
compound
Va
Vb
Vc
Vd
Ve
Vf
Vg
plant growth regulatory activities
50.0
60.0
80.0
-20.0
-20.6
63.7
98.2
compound
Vm
Vn
Vo
Vp
Vq
Vr
Vs
plant growth regulatory activities
60.0
95.4
115.0
145.0
85.0
85.0
110.0
1
1
3
Data for II1. Yield, 86.3%; mp, 133- 135 °C. H NMR (CDCl3):
δ 4.87 (s, 2H, CH2), 7.41 (s, 3H, Ar-H), 7.67 (s, 1H, Ar-H), 7.72
(m, 2H, Ar-H), 7.87 (m, 2H, Ar-H), 7.99 (s, 2H, Ar-H).
Data for III3. Yield, 72.7%. H NMR (CDCl3): δ 1.19 [d, JHH
)
6.8 Hz, 6H, (CH3)2CH], 1.70 (brs, 2H, NH2), 2.85-2.92 [m, 1H,
(CH3)2CH], 3.85 (s, 2H, CH2), 6.56 (s, 1H, Ar-H).
1
Data for II2. Yield, 92.6%; mp, 135- 137 °C. H NMR (CDCl3):
Data for III4. Yield, 70.5%. 1H NMR (CDCl3): δ 1.74 (s, 2H, NH2),
2.27 (s, 3H, CH3), 3.87 (s, 2H, CH2), 6.62 (s, 1H, Ar-H).
δ 4.86 (s, 2H, CH2), 7.35 (s, 2H, Ar-H), 7.69-7.73 (m, 3H, Ar-H),
7.86-7.92 (m, 3H, Ar-H), 7.98 (s, 1H, Ar-H).
1
Data for III5. Yield, 84.7%. H NMR (CDCl3): δ 4.32 (brs, 2H,
Data for II3. Yield, 91.1%; mp, 140-142 °C. 1H NMR (CDCl3): δ
1.21 [d, 3JHH ) 6.8 Hz, 6H, (CH3)2CH], 2.88-2.95 [m, 1H, (CH3)2CH],
4.94 (s, 2H, CH2), 6.60 (s, 1H, Ar-H), 7.74-7.76 (m, 2H, Ar-H),
7.86-7.89 (m, 2H, Ar-H).
CH2), 5.31 (s, 2H, NH2), 7.69 (d, 3JHH ) 8.4 Hz, 2H, Ar-H), 7.82 (d,
3JHH ) 8.4 Hz, 2H, Ar-H).
Data for III6. Yield, 92.9%. 1H NMR (CDCl3): δ 1.72 (s, 2H, NH2),
4.15 (s, 2H, CH2), 7.16 (t, 3JHH ) 8.4 Hz, 2H, Ar-H), 8.05-8.09 (m,
2H, Ar-H).
1
Data for II4. Yield, 71.9%; mp, 138- 140 °C. H NMR (CDCl3):
1
δ 2.27 (s, 3H, CH3), 4.94 (s, 2H, CH2), 6.64 (s, 1H, Ar-H), 7.74-7.77
(m, 2H, Ar-H), 7.89-7.92 (m, 2H, Ar-H).
Data for III7. Yield, 87.2%. H NMR (CDCl3): δ 3.02 (brs, 2H,
NH2), 4.23 (s, 2H, CH2), 7.37 (d, 3JHH ) 8.4 Hz, 1H, Ar-H), 7.51 (t,
1
3
Data for II5. Yield, 95.2%; mp, 146- 147 °C. H NMR (CDCl3):
3JHH ) 6.8 Hz, 1H, Ar-H), 7.69 (t, JHH ) 6.8 Hz, 1H, Ar-H), 7.79
3
3
3
δ 5.19 (s, 2H, CH2), 7.70 (d, JHH ) 8.0 Hz, 2H, Ar-H), 7.81-7.83
(d, JHH ) 8.8 Hz, 1H, Ar-H), 8.04 (d, JHH ) 6.8 Hz, 1H, Ar-H),
3
3
(m, 2H, Ar-H), 7.95-7.97 (m, 2H, Ar-H), 8.15 (d, JHH ) 8.0 Hz,
8.10 (d, JHH ) 8.8 Hz, 1H, Ar-H).
2H, Ar-H).
Data for III8. Yield, 78.3%. 1H NMR (CDCl3): δ 1.80 (s, 2H, NH2),
Data for II6. Yield, 96.7%; mp, 144-146 °C. 1H NMR (CDCl3): δ
5.17 (s, 2H, CH2), 7.12 (t, 3JHH ) 8.4 Hz, 2H, Ar-H), 7.80-7.82 (m,
2H, Ar-H), 7.94-7.96 (m, 2H, Ar-H), 8.00-8.04 (d, 3JHH ) 8.0 Hz,
2H, Ar-H).
3.87 (s, 2H, CH2), 7.38 (t, 3JHH ) 6.8 Hz, 1H, Ar-H), 7.53 (t, 3JHH
)
6.8 Hz, 1H, Ar-H), 7.62 (d, 3JHH ) 8.0 Hz, 1H, Ar-H), 7.86 (s, 1H,
3
4
Ar-H), 7.97 (d, JHH ) 8.0 Hz, 1H, Ar-H), 8.70 (d, JHH ) 2.4 Hz,
1H).
Data for II7. Yield, 90.0%; mp, 171-173 °C. 1H NMR (CDCl3): δ
Data for III9. Yield, 73.5%. 1H NMR (CDCl3): δ 1.70 (s, 2H, NH2),
4.05 (s, 2H, CH2), 7.35-7.39 (m, 1H, Ar-H), 7.64-7.66 (m, 1H,
Ar-H), 7.73 (s, 1H, Ar-H), 8.05 (d, 3JHH ) 8.8 Hz, 1H, Ar-H), 8.11
5.20 (s, 2H, CH2), 7.36 (d, 3JHH ) 8.8 Hz, 1H, Ar-H), 7.49 (t, 3JHH
)
3
7.6 Hz, 1H, Ar-H), 7.65 (t, JHH ) 7.6 Hz, 1H, Ar-H), 7.75-7.78
(m, 3H, Ar-H), 7.90-7.92 (m, 2H, Ar-H), 7.97 (d, JHH ) 8.4 Hz,
3
3
(d, JHH ) 8.8 Hz, 1H, Ar-H), 8.85-8.87 (m, 1H, Ar-H).
1H, Ar-H), 8.10 (d,3JHH ) 8.4 Hz, 1H, Ar-H).
General Synthetic Procedures for the Title Compounds V. A
mixture of IVa (or IVb or IVc, prepared according to our previous
work; 14, 15) (1.35 mmol), crude III (1.45 mmol), and ethanol (20
mL) was refluxed for 1.5-2 h [monitored by thin-layer chromatography
(ethyl acetate/petroleum ether (60-90 °C), 1:2, v/v)] and then
evaporated under reduced pressure to give crude product. The residue
was purified by vacuum column chromatography on a silica gel [eluent,
ethyl acetate/petroleum ether (60-90 °C), 1:2, v/v] to afford the title
compounds.
Data for II8. Yield, 92.1%; mp, 154-156 °C. 1H NMR (CDCl3): δ
5.05 (s, 2H, CH2), 7.54 (t, 3JHH ) 6.9 Hz, 1H, Ar-H), 7.67-7.74 (m,
3H), 7.80 (d, 3JHH ) 8.1 Hz, 1H, Ar-H), 7.85-7.88 (m, 2H, Ar-H),
8.09 (d, 3JHH ) 8.1 Hz, 1H, Ar-H), 8.22 (s, 1H, Ar-H), 9.03 (s, 1H,
Ar-H).
Data for II9. Yield, 91.5%; mp, 163-165 °C. 1H NMR (CDCl3): δ
5.03 (s, 2H, CH2), 7.37-7.40 (m, 1H, Ar-H), 7.71-7.80 (m, 7H,
3
Ar-H), 7.66 (s, 1H, Ar-H), 8.17 (t, JHH ) 7.5 Hz, 2H, Ar-H),
1
8.91-8.94 (m, 1H, Ar-H).
Data for Va. Yield, 96.8%; mp, 51-52 °C. H NMR (CDCl3): δ
3
General Synthetic Procedures for III. To a suspension of N-
substituted phthalimide II (4 mmol) in ethanol (20 mL) was added
hydrazine hydrate (50%, 0.48 g, 4.8 mmol). The reaction mixture was
refluxed for 5 h and then cooled. The precipitated phthalylhydrazide
was filtered off and washed with ethanol, and then, the filtrate was
concentrated under reduced pressure to give crude III, which was
utilized in the next reaction without further purification.
1.18 (t, JHH ) 7.2 Hz, 3H, CH2CH3), 2.72 (s, 3H, SCH3), 3.55 (q,
3JHH ) 7.2 Hz, 2H, CH2CH3), 3.67 (t, 3JHH ) 5.2 Hz, 2H, OCH2), 4.28
3
3
(t, JHH ) 5.2 Hz, 2H, OCH2), 4.75 (d, JHH ) 5.6 Hz, 2H, NCH2),
7.44-7.46 (m, 3H, Ar-H), 7.62 (s, 1H, Ar-H), 7.99-8.01 (m, 2H,
Ar-H), 10.30 (brs, 1H, NH). Anal. calcd for C19H21N3O4S (%): C,
58.90; H, 5.46; N, 10.85. Found: C, 59.09; H, 5.79; N, 11.49.
Data for Vb. Yield, 85.3%; oil. 1.19 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
1.46 [d, 3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.29-3.36 [m, 1H, CH(CH3)2],
1
Data for III1. Yield, 73.3%. H NMR (CDCl3): δ 1.75 (brs, 2H,
NH2), 3.83 (s, 2H, CH2), 7.42-7.43 (m, 3H, Ar-H), 7.53 (s, 1H,
3.56 (q, JHH ) 7.2 Hz, 2H, CH2CH3), 3.68 (t,3JHH ) 5.2 Hz, 2H,
3
3
3
Ar-H), 7.99-8.01 (s, 2H, Ar-H).
OCH2), 4.27 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.57 (d, JHH ) 5.6 Hz,
2H, NCH2), 7.45-7.47 (m, 3H, Ar-H), 7.62 (s, 1H, Ar-H), 8.00-8.02
(m, 2H, Ar-H), 10.56 (brs, 1H, NH). HRMS, m/z 382.1772. Calcd
for C21H25N3O4 - H, 382.1767.
Data for III2. Yield, 78.8%. 1H NMR (CDCl3): δ 3.83 (s, 2H, NH2),
7.35-7.41 (m, 2H, Ar-H), 7.56 (s, 1H, Ar-H), 7.89 (d, JHH ) 7.6
3
Hz, 1H, Ar-H), 8.01 (s, 1H, Ar-H).

Novel 2-Cyanoacrylates
J. Agric. Food Chem., Vol. 57, No. 7, 2009 2853
3
3
Data for Vc. Yield, 88.1%; mp, 83-84 °C. 1.19 (t, 3JHH ) 7.2 Hz,
CH2CH3), 3.73 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.36 (t, JHH ) 5.2 Hz,
3 3
3
3H, CH2CH3), 2.72 (s, 3H, SCH3), 3.55 (q, JHH ) 7.2 Hz, 2H,
2H, OCH2), 5.06 (d, JHH ) 4.8 Hz, 2H, NCH2), 7.31 (d, JHH ) 8.8
3 3
3
3
CH2CH3), 3.68 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.28 (t, JHH ) 5.2 Hz,
Hz, 1H, Ar-H), 7.57 (t, JHH ) 7.6 Hz, 1H, Ar-H), 7.75 (t, JHH )
3
2H, OCH2), 4.75 (d, JHH ) 5.6 Hz, 2H, NCH2), 7.36-7.42 (m, 2H,
7.6 Hz, 1H, Ar-H), 7.83 (d, 3JHH ) 8.0 Hz, 1H, Ar-H), 8.13 (d, 3JHH
) 8.0 Hz, 1H, Ar-H), 8.18 (d, 3JHH ) 8.8 Hz, 1H, Ar-H), 11.03 (brs,
1H, NH). Anal. calcd for C19H21N3O3S: C, 61.44; H, 5.70; N, 11.31.
Found: C, 61.41; H, 5.79; N, 11.49.
Ar-H), 7.63 (s, 1H, Ar-H), 7.88 (d, 3JHH ) 7.6 Hz, 1H, Ar-H), 7.99
(s, 1H, Ar-H), 10.30 (brs, 1H, NH). Anal. calcd for C19H20ClN3O4S
(%): C, 54.09; H, 4.78; N, 9.96; Found: C, 54.11; H, 4.79; N, 9.70.
Data for Vd. Yield, 90.9%; oil. 1.20 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
1.46 [d, 3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.27-3.34 [m, 1H, CH(CH3)2],
3
Data for Vn. Yield, 84.0%; mp, 117-118 °C. 1.22 (t, JHH ) 6.8
Hz, 3H, OCH2CH3), 1.30 (t, 3JHH ) 7.6 Hz, 3H, vinyl-CH2CH3), 2.72
3
3
3
3
3.56 (q, JHH ) 7.2 Hz, 2H, CH2CH3), 3.69 (t, JHH ) 5.2 Hz, 2H,
(q, JHH ) 7.6 Hz, 2H, vinyl-CH2CH3), 3.59 (q, JHH ) 6.8 Hz, 2H,
3 3
3
3
OCH2), 4.27 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.57 (d, JHH ) 5.6 Hz,
2H, OCH2), 7.38-7.45 (m, 2H, Ar-H), 7.64 (s, 1H, Ar-H), 7.89 (d,
3JHH ) 7.6 Hz, 1H, Ar-H), 8.00 (s, 1H, Ar-H), 10.56 (brs, 1H, NH).
HRMS, m/z 416.1383. Calcd for C21H24ClN3O4 - H, 416.1377.
Data for Ve. Yield, 63.8%; mp, 73-74 °C. 1.21 (t, 3JHH ) 6.9 Hz,
3H, CH2CH3), 2.32 (s, 3H, Ar-CH3), 2.70 (s, 3H, SCH3), 3.57 (q,
3JHH ) 6.9 Hz, 2H, CH2CH3), 3.70 (t, 3JHH ) 5.1 Hz, 2H, OCH2), 4.32
OCH2CH3), 3.72 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.35 (t, JHH ) 5.2
3 3
Hz, 2H, OCH2), 4.86 (d, JHH ) 5.6 Hz, 2H, NCH2), 7.32 (d, JHH
)
3
3
8.8 Hz, 1H, Ar-H), 7.57 (t, JHH ) 8.0 Hz, 1H, Ar-H), 7.76 (t, JHH
3
) 8.0 Hz, 1H, Ar-H), 7.83 (d, JHH ) 8.0 Hz, 1H, Ar-H), 8.13 (d,
3JHH ) 8.0 Hz, 1H, Ar-H), 8.19 (d, 3JHH ) 8.8 Hz, 1H, Ar-H), 10.87
(brs, 1H, NH). Anal. calcd for C20H23N3O3: C, 67.97; H, 6.56; N, 11.89.
Found: C, 67.72; H, 6.53; N, 12.00.
3
3
(t, JHH ) 5.1 Hz, 2H, OCH2), 4.84 (d, JHH ) 5.7 Hz, 2H, NCH2),
6.72 (s, 1H, Ar-H), 10.43 (brs, 1H, NH). Anal. calcd for C14H19N3O4S
(%): C, 51.68; H, 5.89; N, 12.91. Found: C, 51.65; H, 5.93; N, 12.70.
Data for Vf. Yield, 88.1%; oil. 1.21 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
1.25 [d, 3JHH ) 6.9 Hz, 6H, CH(CH3)2], 2.70 (s, 3H, SCH3), 2.92-3.00
[m, 1H, CH(CH3)2], 3.57 (q,3JHH ) 7.2 Hz, 2H, CH2CH3), 3.70 (t, 3JHH
Data for Vo. Yield, 75.0%; mp, 74-75 °C. 1.22 (t, 3JHH ) 6.9 Hz,
3H, CH2CH3), 1.43 [d, 3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.22-3.33 [m,
1H, CH(CH3)2], 3.60 (q, 3JHH ) 7.2 Hz, 2H, CH2CH3), 3.73 (t, 3JHH
)
3
3
5.4 Hz, 2H, OCH2), 4.35 (t, JHH ) 5.4 Hz, 2H, OCH2), 4.91 (d, JHH
3
) 5.7 Hz, 2H, NCH2), 7.33 (d, JHH ) 8.7 Hz, 1H, Ar-H), 7.57 (t,
3JHH ) 7.8 Hz, 1H, Ar-H), 7.76 (t, JHH ) 7.8 Hz, 1H, Ar-H), 7.83
3
3
3
3
) 5.1 Hz, 2H, OCH2), 4.32 (t, JHH ) 5.1 Hz, 2H, OCH2), 4.85 (d,
(d, JHH ) 7.5 Hz, 1H, Ar-H), 8.13 (d, JHH ) 7.5 Hz, 1H, Ar-H),
8.20 (d,3JHH ) 8.7 Hz, 1H, Ar-H), 11.21 (brs, 1H, NH). Anal. calcd
for C21H25N3O3: C, 68.64; H, 6.86; N, 11.44. Found: C, 68.54; H, 6.76;
N, 11.45.
3JHH ) 5.7 Hz, 2H, NCH2), 6.68 (s, 1H, Ar-H), 10.44 (brs, 1H, NH).
HRMS, m/z 376.1301. Calcd for C16H23N3O4S + Na, 376.1307.
Data for Vg. Yield, 70.4%; oil. 1.21 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
3
3
1.25 [d, JHH ) 6.9 Hz, 6H, Ar-CH(CH3)2], 1.41 [d, JHH ) 6.9 Hz,
6H, vinyl-CH(CH3)2], 2.92-3.01 [m, 1H, CH, Ar-CH(CH3)2], 3.20-3.29
[m, 1H, CH, vinyl-CH(CH3)2], 3.58 (q, 3JHH ) 7.2 Hz, 2H, CH2CH3),
3.70 (t,3JHH ) 5.1 Hz, 2H, OCH2), 4.31 (t, 3JHH ) 5.1 Hz, 2H, OCH2),
Data for Vp. Yield, 96.8%; oil. 1.21 (t, 3JHH ) 6.9 Hz, 3H, CH2CH3),
3
2.68 (s, 3H, SCH3), 3.57 (q, JHH ) 6.9 Hz, 2H, CH2CH3), 3.70 (t,
3JHH ) 5.1 Hz, 2H, OCH2), 4.31 (t, JHH ) 5.1 Hz, 2H, OCH2), 4.99
3
(d,3JHH ) 6.0 Hz, 2H, NCH2), 7.43-7.47 (m, 1H, Ar-H), 7.57-7.61
(m, 1H, Ar-H), 7.66 (s, 1H, Ar-H), 8.14-8.16 (m, 2H, Ar-H),
8.93-8.95 (m, 1H, Ar-H), 10.48 (brs, 1H, NH). Anal. calcd for
C19H21N3O3S: C, 61.44; H, 5.70; N, 11.31. Found: C, 61.27; H, 5.52;
N, 11.29.
3
4.65 (d, JHH ) 5.7 Hz, 2H, NCH2), 6.70 (s, 1H, Ar-H), 10.71 (brs,
1H, NH). HRMS, m/z 372.1894. Calcd for C18H27N3O4 + Na, 372.1899.
Data for Vh. Yield, 79.4%; mp, 79-81 °C. 1.22 (t, 3JHH ) 7.2 Hz,
3
3H, CH2CH3), 2.72 (s, 3H, SCH3), 3.58 (q, JHH ) 6.8 Hz, 2H,
3
3
CH2CH3), 3.72 (t, JHH ) 4.8 Hz, 2H, OCH2), 4.35 (t, JHH ) 4.8 Hz,
Data for Vq. Yield, 90.6%; oil. 1.20 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
3
3
2H, OCH2), 5.11 (d, JHH ) 6.4 Hz, 2H, NCH2), 7.76 (d, JHH ) 8.4
Hz, 2H, Ar-H), 8.21 (d,3JHH ) 8.4 Hz, 2H, Ar-H), 10.53 (brs, 1H,
NH). Anal. calcd for C19H19F3N4O4S: C, 50.00; H, 4.20; N, 12.27.
Found: C, 50.27; H, 4.28; N, 12.13.
1.35 [d,3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.17 [s, 1H, CH(CH3)2], 3.56
3
3
(q, JHH ) 6.8 Hz, 2H, CH2CH3), 3.69 (t, JHH ) 5.2 Hz, 2H, OCH2),
4.28 (t, 3JHH ) 5.2 Hz, 2H, OCH2), 4.78 (d, 3JHH ) 6.0 Hz, 2H, NCH2),
7.42-7.45 (m, 1H, Ar-H), 7.56-7.58 (m, 1H, Ar-H), 7.65 (s, 1H,
Ar-H), 8.14-8.16 (m, 2H, Ar-H), 8.91-8.93 (m, 1H, Ar-H),
10.71(brs, 1H, NH). Anal. calcd for C21H25N3O3: C, 68.64; H, 6.86;
N, 11.44. Found: C, 68.44; H, 6.80; N, 11.32.
Data for Vi. Yield, 47.1%; oil. 1.21 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
1.46 [d, 3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.17 [m, 1H, CH(CH3)2], 3.58
3
3
(q, JHH ) 7.2 Hz, 2H, CH2CH3), 3.71 (t, JHH ) 4.8 Hz, 2H, OCH2),
4.33 (t, 3JHH ) 4.8 Hz, 2H, OCH2), 4.91 (d, 3JHH ) 6.4 Hz, 2H, NCH2),
7.76 (d, 3JHH ) 8.4 Hz, 2H, Ar-H), 8.21 (d, 3JHH ) 8.4 Hz, 2H, Ar-H),
10.83 (brs, 1H, NH). HRMS, m/z 453.1750. Calcd for C21H23F3N4O4
+ H, 453.1744.
Data for Vr. Yield, 88.1%; mp, 95-96 °C. 1.18 (t, 3JHH ) 6.8 Hz,
3
3H, CH2CH3), 1.37 [d, JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.12 [s, 1H,
CH(CH3)2], 3.55 (q, 3JHH ) 7.2 Hz, 2H, CH2CH3), 3.67 (t, 3JHH ) 5.2
3
3
Hz, 2H, OCH2), 4.27 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.79 (d, JHH
)
)
3
Data for Vj. Yield, 89.5%; mp, 116-117 °C. 1.22 (t, JHH ) 7.2
6.0 Hz, 2H, NCH2), 7.56 (t, 3JHH )8.0 Hz, 1H, Ar-H), 7.73 (t, 3JHH
3
Hz, 3H, CH2CH3), 2.71 (s, 3H, SCH3), 3.58 (q, JHH ) 6.8 Hz, 2H,
8.0 Hz, 1H, Ar-H), 7.81 (d, 3JHH ) 8.0 Hz, 1H, Ar-H), 8.00 (s, 1H,
3
3
3
4
CH2CH3), 3.72 (t, JHH ) 4.8 Hz, 2H, OCH2), 4.36 (t, JHH ) 4.8 Hz,
Ar-H), 8.11 (d, JHH ) 8.0 Hz, 1H, Ar-H), 8.80 (d, JHH ) 2.4 Hz,
1H, Ar-H), 10.68 (brs, 1H, NH). Anal. calcd for C21H25N3O3: C, 68.64;
H, 6.86; N, 11.44. Found: C, 68.89; H, 6.82; N, 11.57.
3
2H, OCH2), 5.08 (d, JHH ) 6.4 Hz, 2H, NCH2), 7.16-7.20 (m, 2H,
Ar-H), 8.06-8.09 (m, 2H, Ar-H), 10.51 (brs, 1H, NH). Anal. calcd
for C18H19FN4O4S: C, 53.19; H, 4.71; N, 13.79. Found: C, 53.18; H,
4.90; N, 13.70.
Data for Vs. Yield, 96.8%; mp, 83-84 °C. 1.18 (t, 3JHH ) 6.8 Hz,
3
3H, CH2CH3), 2.66 (s, 3H, SCH3), 3.54 (q, JHH ) 6.8 Hz, 2H,
3
3
Data for Vk. Yield, 87.2%; oil. 1.20 (t, 3JHH ) 7.2 Hz, 3H, CH2CH3),
CH2CH3), 3.67 (t, JHH ) 5.2 Hz, 2H, OCH2), 4.28 (t, JHH ) 5.2 Hz,
3 3
1.44 [d, 3JHH ) 7.2 Hz, 6H, CH(CH3)2], 3.15 [m, 1H, CH(CH3)2], 3.56
2H, OCH2), 4.96 (d, JHH ) 6.0 Hz, 2H, NCH2), 7.56 (t, JHH ) 8.0
3
3
3
3
(q, JHH ) 7.2 Hz, 2H, CH2CH3), 3.70 (t, JHH ) 4.8 Hz, 2H, OCH2),
4.31 (t, 3JHH ) 4.8 Hz, 2H, OCH2), 4.87 (d, 3JHH ) 6.4 Hz, 2H, NCH2),
7.17-7.20 (m, 2H, Ar-H), 8.05-8.08 (m, 2H, Ar-H), 10.79 (brs,
1H, NH). HRMS, m/z 425.1601. Calcd for C20H23FN4O4 + Na,
425.1596.
Hz, 1H, Ar-H), 7.72 (t, JHH ) 8.0 Hz, 1H, Ar-H), 7.80 (d, JHH )
8.0 Hz, 1H, Ar-H), 7.98 (s, 1H, Ar-H), 8.10 (d, 3JHH ) 8.0 Hz, 1H,
4
Ar-H), 8.80 (d, JHH ) 2.4 Hz, 1H, Ar-H), 10.45 (brs, 1H, NH).
Anal. calcd for C19H21N3O3S: C, 61.44; H, 5.70; N, 11.31. Found: C,
61.30; H, 5.51; N, 11.20.
3
Data for Vl. Yield, 76.0%; mp, 109-110 °C. 1.21 (t, JHH ) 7.2
Herbicidal Activity. Two dicotyledon crops, rape (Brassica napus
L.) and amaranth pigweed (Amaranthus retroflexus), and two
monocotyledon crops, alfalfa (Medicago satiVa L.) and hairy
crabgrass (Digitaria sanguinalis L. Scop.), were used to test the
herbicidal activities of compounds Va-s using a previously reported
procedure (14).
Plant Growth Regulatory Activities. The plant growth regulatory
activities of the title compounds were evaluated using seeds of
cucumber, and the procedures were previously reported in
literature (19, 20).
Hz, 3H, OCH2CH3), 1.31 (t, 3JHH ) 7.6 Hz, 3H, vinyl-CH2CH3), 2.72
3
3
(q, JHH ) 7.6 Hz, 2H, vinyl-CH2CH3), 3.57 (q, JHH ) 7.2 Hz, 2H,
3
3
OCH2CH3), 3.71 (t, JHH ) 4.8 Hz, 2H, OCH2), 4.33 (t, JHH ) 4.8
Hz, 2H, OCH2), 4.83 (d, JHH ) 6.4 Hz, 2H, NCH2), 7.17-7.21 (m,
3
2H, Ar-H), 8.06-8.10 (m, 2H, Ar-H), 10.40 (brs, 1H, NH). Anal.
calcd for C19H21FN4O4: C, 58.76; H, 5.45; N, 14.43. Found: C, 58.53;
H, 5.62; N, 14.25.
Data for Vm. Yield, 80.0%; mp, 83-84 °C. 1.22 (t, 3JHH ) 6.8 Hz,
3
3H, CH2CH3), 2.71 (s, 3H, SCH3), 3.59 (q, JHH ) 6.8 Hz, 2H,

2854 J. Agric. Food Chem., Vol. 57, No. 7, 2009
Zhao et al.
acterized by 1H NMR and elemental analysis (or HRMS). Their
herbicidal activities against four weeds and plant growth
regulatory activities were evaluated. Some compounds exhibited
excellent herbicidal activities at a dose of 375 g/ha, while most
of these cyanoacrylates presented interesting plant growth
regulatory activities.
RESULTS AND DISCUSSION
Synthesis. The synthesis of target compounds Va-Vs was
started from preparation of halomethyl-substituted hetero-
cycles I1-I9, which were the key intermediates in the whole
routes. The synthetic routes of phenyl-substituted oxazolm-
ethylchloride I1-I2 were different from that of alkyl-
substituted oxazolmethylchloride I3-I4. In detail, 2-phenyl-
4-oxazolmethylchlorideI1andI2werepreparedby2-chloroacetyl
chloride and different benzamides (Scheme 1), whereas
2-(chloromethyl)-5-alkyloxazole I3 and I4 were synthesized
via diazo compounds 3a,b starting from corresponding acyl
chloride 2a,b (Scheme 2).
LITERATURE CITED
(1) Phillips, J. N.; Huppatz, J. L. Cyanoacrylate inhibitors of the Hill
reaction III. Stereochemical and electronic aspects of inhibitor
binding. Z. Naturforsch. 1984, 39C, 617–622.
(2) Huppatz, J. L.; Mcfadden, H. G.; Huber, M.-L.; McCaffery, L. F.
Cyanoacrylate inhibitors of photosynthetic electron transport.
Structural requirements for inhibitor potency and herbicidal
activity. In Synthesis and Chemistry of Agrochemicals III; Baker,
D. R., Fenyes, J. G., Steffens, J. J., Eds.; Maple Press: New York,
1992; pp 186-199.
(3) Mackay, S. P.; O’Malley, P. J. Molecular modelling of the
interaction of cyanoacrylate inhibitors with photosystem II. Part
I. Z. Naturforsch. 1993, 48C, 773–781.
4-Trifluoromethyl- or 4-fluoro-benzonitrile 4 and hydroxy-
lamine hydrochloride were refluxed in ethanol in the presence
of sodium hydroxide to give compounds 5, which was reacted
with chloroacetyl chloride to afford intermediates 6a and 6b,
respectively. Compounds 6 were refluxed in xylene to give
3-phenyl-1,2,4-oxadiazole-5-methylchloride I5 and I6
(Scheme 3).
Different methyl-substituted quinoline was reacted with NBS
or NCS in the presence of AIBN to give quinolinylmethylbro-
mide I7, I8, or I9, which was allowed to proceed the next step
as soon as possible to avoid polymerization (Scheme 4).
Alkyoxy- or methylthio-substituted cyanoacrylate IV was
prepared according to our previous work (14, 15). Arylmethy-
lamines III1-III9 were synthesized from the corresponding
halomethyl compounds I1-I9 by Gabriel reaction (Scheme 5).
The title compounds Va-Vs were synthesized from IV and
III with good yields (Scheme 6 and Tables 1 and 2).
Herbicidal Activity Bioassay. Herbicidal activities of the
title compounds Va-Vs are listed in Table 3. In postemer-
gence treatment, most of the title compounds showed higher
herbicidal activities as compared to preemergence treatment,
and these compounds exhibited higher herbicidal activities
against dicotyledon weeds (rape and amaranth pigweed) than
against monocotyledon weeds (alfalfa and hairy crabgrass).
For instance, the herbicidal activities of Vi, Vk, Vp, Vr, and
Vs against rape and amaranth pigweed were 100% at 1.5
kg/ha in postemergence treatment, while Vd and Vg showed
activities above 80% at the same dose. Interestingly, the
herbicidal activities of Vb and Vk against hairy crabgrass
were 87.2 and 82.5%, respectively. Furthermore, in preemer-
gence treatment, Vk and Vs exhibited good herbicidal
activities, 88.0 and 74.9% in detail, which were different from
most of the 2-cyanoacrylates reported in our previous
work (13-16).
Compound Vr exhibited excellent herbicidal activity at 750
g/ha; however, its activity decreased remarkably when the dose
was reduced to 375 g/ha. At the rate of 375 g/ha, compounds
Vp and Vs still showed excellent herbicidal activities; the results
indicate that introduction of quinoline was effective for the
herbicidal activities (Table 4).
Plant Growth Regulatory Activities. The plant growth
regulatory activities of compounds Va-Vg and Vm-Vs were
evaluated, and their effects on the radicle growth of cucumber
are listed in Table 5. Interestingly, most of these compounds,
such as Vg, Vn, Vo, Vp, and Vs, stimulated radicle growth
of cucumber and showed nearly or more than 100% promo-
tion, whereas other compounds, such as Vd and Ve, had an
inhibitory effect, 20.0 and 18.6% inhibition, respectively.
In conclusion, a series of novel 2-cyanoacrylates containing
an oxazole, oxadiazole, or quinoline moiety were synthesized
from corresponding arylmethylamine and alkyoxy- or meth-
ylthio-substituted cyanoacrylate, and their structures were char-
(4) Huppatz, J. L. Quantifying the inhibitor-target site interactions
of photosystem II herbicides. Weed Sci. 1996, 44, 743–748.
(5) Liu, Y. X.; Wei, D. G.; Zhu, Y. R.; Liu, S. H.; Zhang, Y. L.;
Zhao, Q. Q.; Cai, B. L.; Li, Y. H.; Song, H. B.; Liu, Y.; Wang,
Y.; Huang, R. Q.; Wang, Q. M. Synthesis, herbicidal activities,
and 3D-QSAR of 2-cyanoacrylates containing aromatic methy-
lamine moieties. J. Agric. Food Chem. 2008, 56, 204–212.
(6) Li, H. K.; Diao, Y. M.; Wang, H. X.; Chen, C. J.; Ni, J. P.; Zhou,
M. G. JS399--19, a new fungicide against wheat scab. Crop Prot.
2008, 27, 90–95.
(7) Zhou, M. G.; Wang, J. X.; Li, H. K. Method for preventing and
controlling wheat bakanae disease by JS399-19 and tebuconazole.
CN 1899040, 2007.
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L.; Xue, W. Synthesis and antiviral activity of novel chiral
cyanoacrylate derivatives. J. Agric. Food Chem. 2005, 53, 7886–
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Received for review November 20, 2008. Revised manuscript received
February 12, 2009. Accepted February 17, 2009. This work was
financially supported by the National Natural Science Foundation of
China (20872072).
JF803632T