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* E-mail: nkzml@vip.163.com; Tel.: 0086-022-23505376; Fax: 0086-022-23505948 Received November 27, 2010; revised March 21, 2011; accepted April 12, 2011. Project supported by the National Basic Research Program of China (No. 2010CB126106) and the National Natural Science Foundation of China

(No. 20872069)

Chin. J. Chem. 2011, 29, 1651—1655 © 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1651

Synthesis and Insecticidal Evaluation of Novel N-Pyridylpyrazolecarboxamides Containing Different

Substituents in the ortho-Position

Feng, Qi(冯启) Yu, Guanping(于观平) Xiong, Lixia(熊丽霞) Wang, Mingzhong(王明忠) Li, Zhengming*(李正名)

State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China

In order to look for novel insecticides containing N-pyridylpyrazole, ten novel pyrazolecarboxamides containing different ortho-substituents in the aniline part were synthesized, and their structures were characterized by 1H NMR, 13C NMR and HRMS. The single crystal structure of 10b was determined by X-ray diffraction. Their evaluated in-secticidal activity against oriental armyworm (Mythimna separata) indicated that all the compounds exhibited mod-erate insecticidal activities.

Keywords insecticidal activity, N-pyridylpyrazole, pyrazolecarboxamide, ortho-substituents

Introduction

Since the introduction of chlorantraniliprole (Figure 1, A) as an insecticide for crop protection in recent years,1 several anthranilic diamides insecticides have been developed due to their high potency, low mam-malian toxicity, broad insecticidal spectra, and new mode of action.2,3 From their chemical structures, two features are evident: one is the N-pyridylpyrazole moi-ety, the other is the anthranilamide moiety. Previous research indicated that some modification focused on the anthranilamide while preserving the N-pyridyl- pyrazole.4 However, the amides in the ortho-position have been changed a lot in the reported patents, such as heterocyclic groups,5,6 N-alkoxy amides,7 cyano- containing amides,8 etc. Recently a novel pyrazolecar-boxamide with thiadiazol group in the ortho-position (Figure 1, B, JS 9117) was reported with high insecti-cidal activity,9,10 indicating the ortho-position is still attractive in further modification. In this article, novel pyrazolecarboxamides containing different ortho- substituents in the aniline part, including methylene acohols, methylene amines, aldehydes, oximes and thi-azolidines, were synthesized as shown in Scheme 1 and their insecticidal activity against oriental armyworm was tested accordingly.

Experimental

Materials and instruments

NMR spectra were recorded at 400 MHz using a

Figure 1 Chemical structures of compounds A and B.

Bruker AV-400 spectrometer in CDCl3 or DMSO-d6

solution with tetramethylsilane as the internal standard, High-resolution mass spectrometry (HRMS) data were obtained on a Varian QFT-ESI instrument. The melting points were determined on an X-4 binocular microscope melting point apparatus (Beijing Tech Instruments Co., Beijing, China) and were uncorrected. Manganese di-oxide (activated, tech.) was purchased from Alfa Aesar. Reagents were all analytically pure. All solvents and liquid reagents were dried by standard methods in ad-vance and distilled before use. Chlorantraniliprole was synthesized according to the literature11 and used as control.

General procedure

The intermediate 3-bromo-1-(3-chloro-2-pyridyl)- 1H-pyrazole-5-caboxylic acid (4) was synthesized ac-cording to procedure reported by Dong et al.11 The title compounds were prepared as shown in Scheme 1.

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Scheme 1 General synthetic procedure of title compounds 5—11

(2-Amino-5-chloro-3-methylphenyl) methanol (2)

The solution of compound 1 (60.0 mmol) in 20 mL of THF was added dropwise to an ice-cold mixture of lith-ium aluminium hydride (0.120 mol) in 60 mL of THF with the temperature maintained below 5 ℃ throughout. After stirring at 5 ℃ for 3 h, 60 mL of 5% sodium hy-droxide solution was added to quench the reaction. The resulting mixture was extracted with ethyl acetate (40 mL×3). The combined extracts were washed with brine, dried with anhydrous sodium sulfate and evaporated to give the title compound as a dust-color solid. Yield 97.0%, m.p. 83—85 ℃; 1H NMR (CDCl3, 400 MHz) δ: 7.02 (d, J＝2.4 Hz, 1H, Ar-H), 6.93 (d, J＝2.4 Hz, 1H, Ar-H), 4.63 (s, 2H, Ar-CH2), 2.16 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 142.6, 129.9, 126.5, 125.5, 124.4, 121.9, 63.9, 17.2.

2-Amino-5-chloro-3-methylbenzaldehyde (3) Manganese dioxide (4.0 mmol) was added to a solution of compound 2 (2.0 mmol) in 20 mL of dichloro-methane in one portion. The resulting mixture was stirred at room temperature for 6 h, then an additional

portion of manganese dioxide (2.0 mmol) was added and the stirring was continued overnight. Silica gel (2.0 g) was added and the mixture was evaporated, the re-sulting black powder was applied to flash chromatogra-phy on silica gel with petroleum ether/ethyl acetate (4/1, V/V) to give the title compound as a yellow solid. Yield 77.0%, m.p. 114—116 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.81 (s, 1H, CHO), 7.35 (s, 1H, Ar-H), 7.21 (s, 1H, Ar-H), 6.23 (br s, 2H, Ar-NH2), 2.16 (s, 3H, Ar-CH3); 13C NMR (CDCl3, 100 MHz) δ: 193.1, 147.0, 135.6, 132.2, 124.9, 120.3, 117.8, 16.5.

3-Bromo-N-(4-chloro-2-(hydroxymethyl)-6-meth-ylphenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5- carboxamide (5) Carboxylic acid 4 (1.0 mmol) was dissolved in 20 mL of dichloromethane under stirring; oxalyl chloride (1.5 mmol) and a drop of DMF were added successively. After stirring for 2 h at room tem-perature, dichloromethane was removed in vacuum. The residue was dissolved in 20 mL of dichloromethane, and then added dropwise to an ice-cold solution of com-pound 2 (1.0 mmol), pyridine (1.0 mmol) in 20 mL of

Synthesis and Insecticidal Evaluation of Novel N-Pyridylpyrazolecarboxamides

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dichloromethane. The mixture was stirred at room tem-perature for 2 h before it was washed with 2 mol/L hy-drochloric acid, saturated sodium bicarbonate solution and brine successively. The organic layer was dried with sodium sulfate and evaporated. The residue was subjected to flash chromatography on silica gel with petroleum ether/ethyl acetate (2/1, V/V) to give the title compound as white solid. Yield 50.0%, m.p. 92—94 ℃; 1H NMR (CDCl3, 400 MHz) δ: 8.51 (s, 1H, CONH), 8.42 (dd, J＝1.4, 4.6 Hz, 1H, Ar-H), 7.87 (dd, J＝1.6, 8.0 Hz, 1H, Ar-H), 7.37 (dd, J＝4.4, 8.0 Hz, 1H, Ar-H), 7.15 (d, J＝2.0 Hz, 1H, Ar-H), 7.10 (d, J＝2.0 Hz, 1H, Ar-H), 6.90 (s, 1H, Ar-H), 4.48 (s, 2H, Ar-CH2), 2.15 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 156.1, 148.6, 146.8, 139.3, 139.1, 137.6, 137.3, 132.8, 131.8, 130.6, 128.9, 128.2, 126.8, 125.9, 110.4, 63.1, 18.5; HRMS calcd for C17H13BrCl2N4O2Na ([M＋Na] ＋ ) 476.9494, found 496.9491.

2-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole- 5-carboxamido)-5-chloro-3-methylbenzyl acetate (6) Acetyl chloride (0.52 mmol) was added dropwise to an ice-cold solution of compound 5 (0.50 mmol) in 10 mL of pyridine. After stirring for 2 h, 40 mL of water was added to quench the reaction and the solution was ex-tracted with ethyl acetate (40 mL×3). The extracts were combined, washed with 2 mol/L hydrochloride acid and brine, dried, then evaporated. The resulting residue was applied to flash chromatography on silica gel with petroleum ether/ethyl acetate (2/1, V/V) to give the title compound as white solid. Yield 95.8%, m.p. 77—79 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.29 (s, 1H, CONH), 8.46 (dd, J＝1.4, 4.6 Hz, 1H, Ar-H), 7.86 (dd,

J＝1.2, 8.2 Hz, 1H, Ar-H), 7.38 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.25 (d, J＝2.0 Hz, 1H, Ar-H), 7.22 (d, J＝2.4 Hz, 1H, Ar-H), 7.10 (s, 1H, Ar-H), 4.99 (s, 2H, CH2), 2.19 (s, 3H, CH3CO), 2.11 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 172.4, 155.8, 149.0, 146.9, 139.0, 138.8, 138.5, 133.0, 132.7, 131.9, 131.6, 129.0, 128.6, 128.2, 125.8, 110.3, 63.1, 21.0, 18.7; HRMS calcd for C19H15BrCl2N4O3Na ([M ＋ Na] ＋ ) 474.9335, found 474.9335.

3-Bromo-N-(4-chloro-2-formyl-6-methylphenyl)- 1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide (7) This compound was prepared following the same procedure described for compound 5 using 2-amino-5- chloro-3-methylbenzaldehyde (3) instead of compound 2. Yellow solid, yield 60.0%, m.p. 86—88 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.95 (s, 1H, CHO), 9.91 (s, 1H, CONH), 8.46 (d, J＝4.4 Hz, 1H, Ar-H), 7.86 (d, J＝8.0 Hz, 1H, Ar-H), 7.58 (s, 1H, Ar-H), 7.46 (s, 1H, Ar-H), 7.39 (dd, J＝4.4, 8.0 Hz, 1H, Ar-H), 7.09 (s, 1H, Ar-H), 2.21 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 193.0, 155.7, 148.7, 146.9, 139.1, 138.9, 137.8, 137.0, 134.2, 132.1, 132.0, 129.1, 128.9, 128.3, 125.8, 110.9, 19.1; HRMS calcd for C17H11BrCl2N4O2Na ([M＋Na]＋) 518.9591, found 518.9597.

The general synthetic procedure for the compounds 8a—8d

Alkylamine (0.60 mmol) was added to a solution of compound 7 (0.60 mmol) in 20 mL ethanol. The result-ing solution was stirred at room temperature for 2 h, and then the solvent was evaporated. The residue was dis-solved in methanol (20 mL), and sodium borohydride (0.80 mmol) was added. The reaction was stirred for 2 h, and then most of the solvent was evaporated. Ethyl ace-tate (50 mL) was added to the residue, which was washed with potassium carbonate solution (10%, 40 mL) and brine successively. The resulting organic phase was concentrated and subjected to flash chromatography on silica gel with petroleum ether∶ethyl acetate (1∶1, V/V) to give the title compounds 8a—8d.

3-Bromo-N-(4-chloro-2-methyl-6-((methylamino)-methyl)phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole- 5-carboxamide (8a) White solid, yield 50.2%, m.p. 134—136 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.80 (br s, 1H, CONH), 8.50 (d, J＝4.4 Hz, 1H, Ar-H), 7.88 (d, J＝8.0 Hz, 1H, Ar-H), 7.41 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.18 (s, 1H, Ar-H), 7.06 (s, 1H, Ar-H), 6.94 (s, 1H, Ar-H), 3.76 (s, 2H, CH2), 2.48 (s, 3H, CH3NH), 2.20 (s, 3H, Ar-CH3).

3-Bromo-N-(4-chloro-2-((isopropylamino)methyl)- 6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole- 5-carboxamide (8b) White solid, yield 85.0%, m.p. 161—163 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.96 (brs, 1H, CONH), 8.50 (dd, J＝1.4, 4.6 Hz, 1H, Ar-H), 7.87 (dd, J＝1.2, 8.0 Hz, 1H, Ar-H), 7.40 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.16 (s, 1H, Ar-H), 7.06 (s, 1H, Ar-H), 6.92 (s, 1H, Ar-H), 3.78 (s, 1H, CH2), 2.88—2.82 (m, 1H, CH), 2.19 (s, 3H, Ar-CH3), 1.15 (d, J＝6.4 Hz, 6H, CH3).

N-(2-((tert-butylamino)methyl)-4-chloro-6-methyl- phenyl)-3-bromo-1-(3-chloropyridin-2-yl)-1H-pyra- zole-5-carboxamide (8c) White solid, yield 97.5%, m.p. 60—62 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.96 (br s, 1H, CONH), 8.48 (dd, J＝1.2, 4.8 Hz, 1H, Ar-H), 7.82 (dd, J＝1.2, 4.8 Hz, 1H, Ar-H), 7.36 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.12 (s, 1H, Ar-H), 7.05 (s, 1H, Ar-H), 6.91 (s, 1H, Ar-H), 3.71 (s, 2H, CH2), 2.15 (s, 3H, Ar-CH3), 1.15 (s, 9H, C(CH3)3).

3-Bromo-N-(4-chloro-2-((dimethylamino)methyl)-6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H-pyra- zole-5-carboxamide (8d) White solid, yield 45.0%, m.p. 218—220 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.82 (br s, 1H, CONH), 8.49 (d, J＝6.0 Hz, 1H, Ar-H), 7.86 (dd, J＝1.6, 10.8 Hz, 1H, Ar-H), 7.39 (dd, J＝6.2, 10.8 Hz, 1H, Ar-H), 7.16 (s, 1H, Ar-H), 7.00 (s, 1H, Ar-H), 6.86 (s, 1H, Ar-H), 3.41 (s, 2H, CH2), 2.29 (s, 6H, CH3), 2.19 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 154.9, 149.1, 146.9, 139.7, 138.9, 134.0, 131.3, 131.1, 130.4, 129.0, 128.9, 128.1, 127.1, 125.8, 109.7, 62.8, 45.0, 19.0; HRMS calcd for C19H19BrCl2N5O ([M＋H])＋ 482.0150, found 482.0145.

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Compounds 8a—8c were further treated with hy-drochloric acid gas in ethyl ether to give compounds 9a—9c.

3-Bromo-N-(4-chloro-2-methyl-6-((methylamino)-methyl)phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide hydrochloride (9a) White solid, quantitative yield, m.p. 168—170 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.80 (s, 1H, CONH), 9.19 (brs, 2H,

2NH Cl＋ － ), 8.52 (d, J＝4.8 Hz, 1H, Ar-H), 8.21 (d, J＝8.4 Hz, 1H, Ar-H), 7.73 (s, 1H, Ar-H), 7.63 (dd, 1H, J＝4.8, 8.0 Hz, Ar-H), 7.57 (s, 1H, Ar-H), 7.48 (s, 1H, Ar-H), 4.01 (t, J＝5.8 Hz, 2H, CH2), 2.55 (t, J＝5.0 Hz, 3H, CH3), 2.17 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 155.9, 148.3, 147.2, 139.4, 138.9, 133.1, 131.7, 131.6, 130.8, 128.2, 128.1, 127.7, 126.6, 111.4, 47.1, 32.4, 17.8; HRMS calcd for C18H17BrCl2N5O ([M－Cl])＋

467.9984, found 467.9988. 3-Bromo-N-(4-chloro-2-((isopropylamino)meth-

yl)6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H-py- razole-5-carboxamide hydrochloride (9b) White solid, quantitative yield, m.p. 163—165 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.97 (s, 1H, CONH), 9.15 (br s, 2H, 2NH Cl＋ － ), 8.45 (d, J＝3.6 Hz, 1H, Ar-H), 7.84 (d, J＝7.6 Hz, 1H, Ar-H), 7.55 (s, 1H, Ar-H), 7.38—7.34 (m, 2H, Ar-H), 7.27 (s, 1H, Ar-H), 3.82 (s, 2H, CH2), 3.10 (s, 1H, CH), 2.23 (s, 3H, Ar-CH3), 1.18 (d, J＝6.4 Hz, 6H, CH(CH3)2);

13C NMR (CDCl3, 100 MHz) δ: 155.8, 148.4, 147.2, 139.4, 139.3, 138.8, 133.2, 131.8, 131.6, 130.8, 128.8, 127.8, 126.9, 126.7, 111.3, 50.4, 43.4, 18.5, 17.8; HRMS calcd for C20H21BrCl2N5O ([M－Cl])＋496.0305, found 496.0301.

N-(2-((tert-Butylamino)methyl)-4-chloro-6-methyl-phenyl)-3-bromo-1-(3-chloropyridin-2-yl)-1H-pyra- zole-5-carboxamide hydrochloride (9c) White solid, quantitative yield, m.p. 268—271 ℃; 1H NMR (CDCl3, 400 MHz) δ: 10.94 (s, 1H, CONH), 9.01 (br s, 2H,

2NH Cl＋ － ), 8.51 (d, J＝4.0 Hz, 1H, Ar-H), 8.20 (d, J＝8.0 Hz, 1H, Ar-H), 7.77 (s, 1H, Ar-H), 7.63 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.56 (s, 1H, Ar-H), 7.49 (s, 1H, Ar-H), 3.97 (s, 2H, CH2), 2.16 (s, 3H, Ar-CH3), 1.37 (s, 9H, C(CH3)3);

13C NMR (CDCl3, 100 MHz) δ: 155.7, 148.4, 147.1, 139.5, 139.3, 138.7, 133.5, 131.7, 131.6, 130.9, 129.5, 127.8, 126.9, 126.7, 111.1, 57.4, 40.5, 25.0, 17.7; HRMS calcd for C21H23BrCl2N5O ([M－Cl])＋ 510.0454, found 510.0458.

(Z)-3-Bromo-N-(4-chloro-2-((hydroxyimino)meth- yl)-6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H- pyrazole-5-carboxamide (10a) Hydroxylamine hydrochloride (0.30 mmol) was added to a solution of compound 7 (0.15 mmol) in 10 mL pyridine. After stir-ring for 12 h at room temperature, ethyl acetate (50 mL) was added. The mixture was washed with 2 mol/L hy-drochloric acid, saturated sodium bicarbonate solution and brine successively. After dried and evaporated, the title compound was obtained as white solid. Yield 98%, m.p. 172—174 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.15 (s, 1H, CONH), 8.44 (dd, J＝1.2, 4.8 Hz, 1H, Ar-H), 8.32 (s, 1H, OH), 8.05 (s, 1H, CH), 7.87 (dd, J＝1.0, 8.2

Hz, 1H, Ar-H), 7.38 (dd, J＝4.4, 8.0 Hz, 1H, Ar-H), 7.21 (s, 1H, Ar-H), 7.19 (s, 1H, Ar-H), 6.92 (s, 1H, Ar-H), 2.18 (s, 3H, CH3);

13C NMR (CDCl3, 100 MHz) δ: 156.3, 148.0, 147.1, 144.2, 139.5, 139.1 (2C), 132.0, 131.9, 131.8, 130.6, 127.4, 127.1, 126.6, 122.4, 110.7, 17.4; HRMS calcd for C17H12BrCl2N5O2Na ([M＋Na]＋) 489.9445, found 489.9444.

3-Bromo-N-(4-chloro-2-((Z)-methoxyiminometh- yl)-6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H- pyrazole-5-carboxamide (10b) This compound was prepared following the same procedure described for compound 10a using methoxamine hydrochloride instead of hydroxylamine hydrochloride. White solid, yield 90%, m.p. 219—220 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.37 (s, 1H, CONH), 8.48 (d, J＝4.0 Hz, 1H, Ar-H), 8.05 (s, 1H, CH), 7.85 (d, J＝8.0 Hz, 1H, Ar-H), 7.39 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.22 (s, 2H, Ar-H), 6.96 (s, 1H, Ar-H), 3.97 (s, 3H, OCH3), 2.20 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 155.7, 148.7, 148.1, 147.0, 139.3, 139.1, 137.6, 132.3, 132.0, 131.4, 128.8, 128.0, 127.8, 127.2, 125.8, 110.3, 62.6, 19.0; HRMS calcd for C18H14BrCl2N5O2Na ([M ＋ Na] ＋ ) 503.9595, found 503.9600.

3-Bromo-N-(4-chloro-2-methyl-6-(thiazolidin-2- yl)phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5- carboxamide (11) To a solution of compound 7 (0.17g, 0.37 mmol) and 2-mercaptoethylamine hydro- chloride (0.084 g, 0.74 mmol) in 20 mL of ethanol, po-tassium acetate (0.073 g, 0.74 mmol) was added in one portion. The resulting suspension was stirred at room temperature for 12 h, and then most of the solvent was removed in vacuum. The residue was dissolved in 50 mL of ethyl acetate, washed with water and brine. The ethyl acetate solution was evaporated and then subjected to flash chromatography using petroleum ether/ethyl acetate (2/1, V/V) as the eluant to give the title com-pound as white solid, yield 67.7%, m.p. 177—179 ℃; 1H NMR (CDCl3, 400 MHz) δ: 9.33 (s, 1H, CONH), 8.44 (d, J＝4.4 Hz, 1H, Ar-H), 7.87 (d, J＝8.4 Hz, Ar-H), 7.51 (s, 1H, Ar-H), 7.37 (dd, J＝4.8, 8.0 Hz, 1H, Ar-H), 7.19 (s, 1H, Ar-H), 6.92 (s, 1H, Ar-H), 5.56 (s, 1H, CH), 3.39—3.33 (m, 1H, CH), 3.24—3.18 (m, 1H, CH), 3.11—3.06 (m, 1H, CH), 3.01—2.96 (m, 1H, CH), 2.19 (s, 3H, Ar-CH3);

13C NMR (CDCl3, 100 MHz) δ: 155.4, 148.7, 146.8, 139.5, 139.2, 137.9, 135.7, 132.5, 131.9, 130.8, 128.8, 128.1, 126.5, 125.8, 110.2, 70.2, 51.6, 35.5, 18.6; HRMS calcd for C19H17BrCl2N5OS ([M＋H]＋) 511.9718, found 511.9709.

Biological activity

The insecticidal activities of compounds 5—11 and chlorantraniliprole were evaluated using the reported procedure.11 The insecticidal activity against oriental armyworm was tested by foliar application, individual corn leaves were placed on moistened pieces of filter paper in Petri dishes. The leaves were then sprayed with the test solution and allowed to dry. Then every 10 fourth-instar oriental armyworm larvae were put into

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each dish. Percent mortalities were evaluated 2 d after treatment. Each treatment was replicated for three times. For comparative purpose, chlorantraniliprole was tested as control under the same conditions.

Results and discussion

Structure of compound 10b

In order to verify the configuration of oxime ether, compound 10b was recrystallized from ethanol to give a colorless crystal for X-ray single-crystal diffraction.12 The crystal with dimensions of 0.22 mm×0.20 mm×

0.18 mm was mounted and analyzed on a Rigaku Sat-urn724 CCD diffractometer with a graphite monochro-matized MoKα radiation (λ＝0.71073 Å) using the ω scan mode (1.82°≤θ≤27.89°) at 113 K. The crystal belongs to a orthorhombic system with space group Pbca and crystal parameters of a＝21.315(3) Å, b＝8.3900(10) Å, c＝22.375(3) Å, V＝4001.4(9) A3, Dc＝

1.604 g/cm3, μ＝2.346 mm－ 1, F(000)＝1936, R＝

0.0328, wR＝0.0736 and Z＝8. Crystal structure of 10b was shown in Figure 2. The average bond lengths and bond angles of the pyridine ring, the phenyl ring and the pyrazole ring were normal.13 The pyrazole and the pyri-dine rings make a dihedral angle of 58.3(3)°. The tor-sion angle of C(17)-N(5)-O(2)-C(18) indicated that the C＝N double bond was in the (Z)-configuration.

Figure 2 Crystal structure of 10b.

Insecticidal activity

The insecticidal activity of compounds 5 — 11 against oriental armyworm was listed in Table 1. Com-pound 5 and its acetylated product 6 showed the same activity, while compounds 10a and 10b containing oxime groups had the similar trend. The activity of compounds 9a—9c and 8d with methylene amines sub-stituted indicated that the change of substituent affected the activity with the trend CH(CH3)2＞C(CH3)3＞CH3

＞two-methyl substituted, and had a decrease in activity compared with their amides analogues. In addition, the thiazolidines 11 did not lead to higher activity compared to its precursor compound 7.

Table 1 Insecticidal activities of compounds 5—11 and chlor-antraniliprole against oriental armyworm

Larvicidal activity/%

Concentration of/(mg•L－1)

Comp. 200 100 50 20

5 100 40

6 100 40

7 100 20

8d 50

9a 80

9b 100 100 100 60

9c 100 100 100 40

10a 100 40

10b 100 60

11 100 10

Chlorantraniliprole 100

References and note

1 Lahm, G. P.; Stevenson, T. M.; Selby, T. P.; Freudenberger, J. H.; Cordova, D.; Flexner, L.; Bellin, C. A.; Dubas, C. M.; Smith, B. K.; Hughes, K. A.; Hollingshaus, J. G.; Clark, C. E.; Benner, E. A. Bioorg. Med. Chem. Lett. 2007, 17, 6274.

2 DuPont Rynaxypyr_ Insect Control Technical Bulletin: http: //www2.dupont.com/Production_Agriculture/en_US/assets/ downloads/pdfs/Rynaxypyr_Tech_Bulletin. pdf

3 Lahm, G. P.; Cordova, D.; Barry, J. D. Bioorg. Med. Chem. 2009, 17, 4127.

4 Feng, Q.; Liu, Z. L.; Xiong, L. X.; Wang, M. Z.; Li, Y. Q.; Li, Z. M. J. Agric. Food Chem. 2010, 58, 12327.

5 Kruger, B.; Hense, A.; Alig, B.; Fischer, R.; Funke, C.; Gesing, E. R.; Malsam, O.; Drewes, M. W.; Arnold, C.; Lummen, P.; Sanwald, E. WO 2007031213, 2007 [Chem. Abstr. 2007, 146, 358885].

6 Clark, D. A.; Finkelstein, B. L.; Lahm, G. P.; Selby, T. P.; Stevenson, T. M. WO 2003016304, 2003 [Chem. Abstr. 2003, 138, 205057].

7 Liu, A. P.; Hu, Z. B.; Wang, Y. J.; Wang, X. G.; Huang, M. Z.; Ou, X. M.; Mao, C. H.; Pang, H. L.; Huang, L. CN 101337959, 2009 [Chem. Abstr. 2009, 150, 168342].

8 Muehlebach, M.; Craig, G. W. WO 2008064891, 2008 [Chem. Abstr. 2008, 149, 10005].

9 Zhang, X. N.; Zhu, H. J.; Tan, H. J.; Li, Y. H.; Ni, J. P.; Shi, J. J.; Zeng, X.; Liu, L.; Zhang, Y. N.; Zhou, Y. L.; He, H. B.; Feng, H. M.; Wang, N. CN 101845043, 2010 [Chem. Abstr. 2010, 153, 530554].

10 Ni, J. P.; Zhang, Y. N.; Zhang, X. N.; Tan, H. J.; Zeng, X. Modern Agrochem. 2010, 9, 21 (in Chinese).

11 Dong, W. L.; Xu, J. Y.; Xiong, L. X.; Liu, X. H.; Li, Z. M. Chin. J. Chem. 2009, 27, 579.

12 Supplementary material CCDC-799316 contains the sup-plementary crystallographic data for this compound. These data can be obtained free of charge at www.ccdc.cam.ac.uk/ conts/retrieving or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB 21EZ, UK; fax: ＋44-1223-336033; email: deposit@ccdc. cam. ac. uk.

13 Liu, X. F.; Liu, X. H. Acta Cryst. 2011, E67, O202.

(E1011271 Sun, H.; Lu, Z.)