CA1131232A - 1-benzoyl-3-(aryloxy-or arylthiopyridinyl) ureas compounds - Google Patents

Abstract

Abstract The present invention relates to novel insecticidal compounds of the formula:

Description

i~3~32 This invention relates to novel insecticidal compounds of the formula:

~R ~ OCH3 wherein each R is independently chloro, fluoro, methyl, or methoxy and is a divisional of Canadian application Serial No. 332~130, filed July 19, 1979. It also relates to methods employing the above compounds as insecticides.
Serial No. 332,130 is directed to compounds of the formula:

s~Rm ~0 ~CNHCI~IH~ R2(CH ) n--R3 \R ~1 ~ .
wherein each R is independently chloro, fluoro, methyl, or methoxy, with the pro~iso that when n is : O, one R is chloro, and R3 is 3-(trifluoromethyl)-phenyl or 2-chloro~5-(trifluoromethyl)phenyl, the other R can zdditionally represent hydrogen; X is oxygen or sulfur; Rl is chloro, methyl, or ethyl; R2 o O
is 0, S, S, or S; each of m and n is independently O
0 or 1; R3 is ''~.

~ ~3~L;232 ~ ..

~lj when n = 1, phenyl or substituted phenyl, and

(2) when n = 0, substituted phenyl, in either instance, substituted phenyl S being ~a) 3,5-dimethylphenyl or (b) a radical of the formula zl ~2 wherein each Z independently represents : (1) Br, . (2) Cl, or

(3) F;
zl represents (1) CF3, ~:
: (2) OCF3, (33 O~2Fs~ or 2 (4) CF2cF2H; and Z represents (1) methyl, (2) ethyl, or (3) methoxy;
with the further limitation that the entire substituted phenyl radical - bears (1) at least one Z or zl, 1~3:123;2 (2) not more than 4 substi-tuents, when all substi-tuents are halo substi-tuents;
(3) not more than 3 substi-tuents, when any one sub-stituent is other than halo;
and

(4) not more than 2 different substituents;
and wherein positions on the pyridine ring are as follows:
(1) the nitrogen to pyridine bond is at the 2-position of the pyridine ring, the -R2-(CH2)n-R3 group is at the

5-position of the pyridine ring, and any Rl is at the 4- or 6-position of the pyridine ring; or (2) the nitrogen to pyridine bond is at the 3~position of the pyridine ring, the -R2-(CH2)n-R3 group is at the

6-pos tion of the pyridine ring, and any R is at the 5~position o the pyridine ring;
and the acid addition salts and N-oxides thereof.

~L~3~3Z
--4~

Detailed Description of the Invention For the purposes of the present appli-cation, the compounds of this invention are named as substituted ureas, with numbering as follows:

/30j---CNHCNH~R~a~CH~)n_R

Thus, the compounds are named as 1-(2-substituted or - 2,6-disubstituted benzoyl)-3-(subs~ituted pyridinyl)-ureas, N-oxides thereof, or acid addition salts thereof.
The compounds of the pxesent invention are rea;dily prepared by the reaction of a benzoyl iso-cyanate or benzoyl isothiocyanate of the formula ~3~23Z
,~ ..

,R
o\ O / ~-C-NCX

~ ~-with an aminopyridine of the formula , / m H2N ~ R -(CH2) n~R3 \N
or an N-oxide thereof. The reaction is a known type of reaction, cf. U.S. 3,748,356. The reaction is conveniently conducted in an organic solvent such as ethyl acetate, at room temperature, and with equi~
molar amounts of the reactants. :~
The acld addition salts~are prepared by reacting a benzoyl urea or benzoyl thiourea product with the desired acid, in conventional procedures.
Acids having a pKa of 3.0 or lower are preferred, and -generally the mineral acids are preferred. ~
The benozyl isocyanates which serve as ;
starting materials are prepared by the reaction of the corresponding benzamide with oxalyl chloride by the method of Speziale et al., J. ~. Chem. 27, 3742 (1962). The benzoyl isothiocyanates are prepared in known procedures by reacting the corresponding benzoyl chlorides with an inorganic thiocyanate, such as ammonium thiocyanate, lead thiocyanate, etc.

~L~L3~Z3'~
, ~ .

The aminopyridines to be employed as starting materials are prepared from the corre-sponding halonitropyridines:
, 02N ~ 3 ~ ~ halo o;~

The halonitropyridine is condensed with a phenol, thiophenol, benzyl alcohol, or benzyl mercaptan of the formula E~R2-(CH2)n-R3 and the resulting nitro compound /4XRm 02N ~ R' (CH )n~R3 is reduced. The former reaction is conducted in a solvent such as DM~, DMSO, etc. and in the presence of a base, such as triethylamine, KOH, LiOH, etc, to serve as a hydrogen halide acceptor. Preferred conditions are equimolar amounts of the reactants in DMF, at room temperature, and with lithium hydroxide as base. The reduction can be carried out in any of various prior art procedures, including SnC12/HCl, catalytic hydrogenation, and powdered iron with ammonium chloride. Preferred conditions are powdered iron and ammonium chloride.
Many of the halonitropyridlnes are com-merically available and all are prepared by known procedures. The 6-halo-3-nitropyridines, bearing an ~L~3~;~3Z
. ~ .

Rl substituent if desired, are readily prepared by the methods of Acharya et al., Chem. Abst. 58, 5623c (1963), Batkowski, Chem. Abst. 70, 106327x (1969), and Hawkins et al., J. ~. Chem. 14, 328 (1949).
The 5-halo-2-nitropyridines are also readily pre-pared, by bromination of a 2-aminopyridine to a 2-amino-5-bromopyridine, in accordance with the procedure of Org. Syn. Coll. 5, 346 (John Wiley and Sonsi N.Y., 1973); the 2-aminopyridine can also bear an R substituent at the 4- or 6-position, in accordance with the definition of the final products of the present invention. Although condensation with a HR2-(CH2)n-R3 compound bearing electron donating substituents can be carried out directly with a 2-amino-5-bromopyridine (see Example 18, below), the 2-amino~5-bromopyridine compound can also be oxidized to the corresponding 5-bromo-2-nitropyridine compound, which undergoes the condensation regardless of the identity of substituents.
The aminopyridine oxides are prepared in prior art procedures, see Deady, Synthetic Communica-tions 7(8), 509-514 11977) and Oxidation, ed. by Augustine, especially Chapter 5 (Marcel Dekker, Inc., N.Y. 1969).
These and numerous other syntheses of pyridine compounds are well known in the literature and are well reviewed in P~ridine and Its Derivatives, ed. by Klingsberg, especially Parts 2 and 3 (Inter-scie~nce Publishers Inc., N.Y., 1961 and 1962).
Many of the phenols, thiophenols, benzyl alcohols, and benzyl mercaptans which serve as starting materials are also commercially available.

~3~L23Z

All can be prepared in prior art procedures. A
convenient procedure for the conversion of a phenol to a thiophenol, or a benzyl alcohol to a benzyl mercaptan, is that of Newman et al., J. Org. Chem.
31, 3980 (1966).
The following examples illustrate the synthesis of the compounds of the present invention.
EXAMPLE 1: 6-(4-CHLOROPHENYLTHIO)-3-NITROPYRIDINE
6-Chloro-3-nitropyridine (4.0 grams) and 4-chlorothiophenol (3.7 grams) were mixed in 100 ml.
of dry DMF and lithium hydroxide (1.2 grams~ added portionwise. After the reaction mixture had stirred for about S minutes, it dar~ened and became warm. It was allowed to stir with a drying tube for 4 hours, poured over ice water and the product separated by filtration. It was crystallized from ethyl acetate-ethanol, yield 5.0 grams, m.p. 13~ 136C.
Calc. for CllH7ClN2O2S: C, 49.54; H, 2-56; N~ 10-50-Found: C, 49.82; H, 2.36; N, 10.60.
EXAMPLE 2: 6-(3,5-DIMETHYLPHENOXY)-3-NITROPYRIDINE
6-Chloro-3-nitropyridine (9.5 grams; 0.06 mole), 3,5-dimethylphenol (7.2 grams; 0.06 mole), and lithium hydroxide (4.0 grams) were mixed in 100 ml.
of dimethyl sulfoxide, and the reaction mixture was stirred overnight (about 17 hours~ at room tempera-ture. The reaction mixture was then poured into ice water. The product was separated by filtration and crystallized from ethyl acetate hexanes, yield 9.5 grams, m.p. 94-95C.
Calc for C13H12N2O3: C, 63.93; H, 4.93; N, 11.47 Found: C, 63.80; H, 5.03; N, 11.64.

~13~32 .

EXAMPLE 3: 6-(4-CHLOROPHENYLTHIO)-3-AMINOPYRIDINE
6-(4-Chlorophenylthio)-3-nitropyridine (1.33 grams) was mixed with ammonium chloride t5.0 grams) in 5 ml. of water and about 50 ml. of 3A
ethanol at 70-80C. Iron powder (3.0 grams) was added portionwise and the reaction mixture heated at 70-80C. with constant stirring, for 4 hours. The solution was filtered hot, solvents were removed, and the residue was washed with water; chloroform used to extract the compound was removed in vacuo. A thick oil was crystallized from ether-hexanes after passing through a flush with ethyl acetate on silica gel.
The product precipitated as a white solid, yield 1.0 g., m.p. 55-57.
Calc. for CllHgClN2S: C, 55.81; H, 3.83; N, 11.83-Found: C, 55.64; H, 3.82; N, 12.02.
EXAMPLE 4: 6-(4-CHLOROPHENYLTHIO)-3-AMINOPYRIDINE
6-Chloro-3-nitropyridine (54.5 grams), 4-chlorothiophenol (50.0 grams), and lithium hy-droxide (12.5 grams) were mixed in about 500 ml. of DMF and stirred overnight (about 18 hours) at room temperature. The reaction mixture was poured into ice-water, filtered, and the separated product washed three times with water and air dried, yield, l00 grams.
.The product, withou~ purification, was suspended in a mixture of 1 liter of 3A ethanol and 200 ml. of water. Ammonium chloride (400 grams) and powdered iron (250 grams) were added and the reaction .

il3~'~3;~:

mixture he~ted to reflux. The reaction became exothermic and refluxed without external heat, for one hour; external heat was supplied and the reaction mixture was refluxed for another hour. The rea~tion mixture was then filtered hot ~hrough Hyflo Super Cel (a diatomaceous earth), extracted with ethyl acetate, washed with water, and solvent removed, yield 58.0 grams. Identity of the product was confirmed by compariso~ of the NMR with the NMR of an authentic sample.
EXAMPLE 5: 6 (4-CHLOROPHENYLSULFONYL)-3-NITROPYRIDINE
Hydrogen peroxide (30%) was added portion-wise at room ~emperature to a solution of 6-(4-chlorophenylthio)-3-nitro~yridine (15.7 grams; 0.06 mole) in about 100 ~1. of acetic acid. The reaction mixture was th~n stirred for 10 hours at 70C. TLC
showed 2 spots. Additional hydrogen peroxide was added and the reaction mixture warmed slightly in a water bath. The product precipitated and was separated by filtration and crystallized from ethanol, yield, 12.7 grams, m.p. 177-180C.
Calc. for CllH7ClN2O4S: C, 44.23; H, 2.36; N~ 9-38-Found: C, 44.47; H, 2.29; N, 9.37.
EXAMPLE 6: 6-(3-(TRIFLUOROMETHYL)PHENYLSULFINYL)-3-AMINOPYRIDINE
6-(3-(Trifluoromethyl)phenylthio)-3-aminopyridine (4.0 grams) was dissolved in 50 ml. of acetone and m-chloroperoxybenzoic acid (4.0 grams) ~3~Z
. .~ ..

added. The solution was allowed to stir at room temperature for 2 hours, and an additional 1.0 gram of m-chloroperoxybenzoic acid was added. The re-action mixture was passed over a column of silica gel with ethyl acetate, and the fraction corresponding to the product collected and crystallized from ethyl acetate-hexanes, yield, 4.0 grams m.p. 74-76C.
Calc. for C12HgF3N2OS: C, 50.35; H, 3.15; N, 9.79.
Found: C, 50.08; H, 3.31; N, 9.84.
10 EXAMPLE 7: 2,6-DICHLOROBENZOYL ISOCYANATE
A one-liter flask was purged with nitrogen while dry 2,6-dichlorobenzamide (125 grams, 0.64 mole) and dry toluene (300 ml.) were added. The nitrogen purge was continued as oxalyl chloride (100 grams, 0.79 mole) was added over a 15-minute period, with stirring. The reaction mixture was then heated to 55Co and stirred overnight (about 18 hours) at 55C~
The reaction mixture was then heated to reflux (111C.) and refluxed for 2 hours. Solvent was removed under vacuum and the product distilled off at 134-135C. flask temperature and 131-132C.
vapor temperature, at 13 mm. vacuum, yield 127.5 25 grams (92. 5%) ~
Calc. for ClgH12C13N3O2S: C, 50.41; H, 2.67; N, 9.28.
Found: C, 50.54; H, 2.97; N, 9.45.

~.~3~23Z

EXAMPLE 8: 1-(2,6-DICHLOROBENZOYL)-3-(6-(4-CHLORO
PHENYLTHIO)-3-PYRIDINYL)UREA
2,6-Dichlorobenzoyl isocyanate (2.16 grams;
0.01 mole) and 6-(4-chlorophenylthio)-3-aminopyridine (2.37 grams; 0.01 mole) were mixed in dry ethyl acetate and stirred for 4 hours. The ethyl acetate was removed in vacuo. TLC showed a 3-spot mixture.
The reaction mixture was then poured over a silica column with ethyl acetate, and the major spot collected.
It was crystallized from ethyl acetate-hexanes, yield 1.5 g., m.p. 160-162C.
Calc. for ClgH12C13N302S: C, 50.41; H, 2.67; N, 9.28.
Found: C, 50.54; H, 2.97; N, 9 45.
15 EXAMPLE 9: 1-(2,6-DIMETHOXYBENZOYL)-3-(6-(4-CHLORO-PHENYL~HIO)-3-PYRIDINYL)UREA
2,6-Dimethoxybenzoyl isocyanate (2.07 grams; 0.01 mole) and 6-(4-chlorophenylthio)-3-aminopyridine l2.37 grams; 0.01 mole) were mixed in 100 ml. of ethyl acetate and stirred at room tem-perature for 3 hours. Solvent was removed in vacuo and the product crystallized from hexanes-ethyl acetate, yield 0.6 gram, m.p. 172 174C.
Calc. for C21H~8ClN304S: C, i6082; H, 4.09; N~ 9.47.
Found: C, 56.66; H, 3.85; N, 9.64.
EXAMPLE 10: 1-t2,6-DIMETHOXYBENZOYL)~3-~6-(4-BROMOPHENOXY)-3-PYRIDINYL)UREA
2,6-Dimethoxybenzoyl isocyanate (2.0 grams) 30 and 6-(4-bromophenoxy)-3-aminopyridlne (2.3 grams) were mixed in about 50 ml. of ethyl aceta~e at room ~3~Z3;~

temperature, and the reaction mixture stirred over-night (about 17 hours) at room temperature. The product was separated by filtration and crystallized from a mixture of ethyl acetate and ethanol, yield 0.9 gram, m.p., 177-179C~ -Calc. for C21H18BrN3O5: C, 53.41; H, 3.84; N, 8.90.
Found: C, 53.19; H, 4.05; N, 9.02.
EXAMPLE 11: 1-(2,6-DIMETHYLBENZOYL)-3-(6-(4-CHLOROPHENYLTHIO)-3-PYRIDINYL)UREA
2,6-Dimethylbenzoyl isocyanate (1.61 grams;
0.01 mole) and 6-(4-chlorophenylthio)-3-aminopyridine (2.36 grams; 0.01 mole) were mixed in 50 ml. of ethyl acetate and stirred at room tempèrature for 12 hours.
Solven~ was removed in vacuo. TLC showed four spots.
The mixture was passed over a column of silica gel with a l:l mixture of toluene-ethyl acetate and the product (Rf - .7) separated and crystallized from ethyl acetate-hexanes, yield 1.1 grams, m.p. lS9-160C.
Calc. for C21H18ClN3O2S: C, 61.23; ~, 4~40; N, 10.20.
Found: C, 61.48; H, 4.70; N, 10.34.
EXAMPLE 12: 1-(2,6-DICHLOROBENZOYL)-3~6-(4-CHLOROPHENYLTHIO)-3-PYRIDINYL)UREA, HYDROCHLORIDE SALT
1-(2,6-bichlorobenzoyl)-3~(6-(4-chloro-phenylthio)-3-pyridinyl)urea (2.0 grams) was refluxed in 100 ml. of concentrated HCl (37%) for 4 hours.
The reaction mixture was cooled and the product separated by filtration, yield 1.5 grams, m.p., 214-217C.

~3~LZ32 .

Calc. for ClgH13C14N3O25: C, 46.65; H, 2.68; N, 8.59.
Found: C, 46.90; H, 2.68; N, 8.44.
EXAMPLE 13~ 2-CEILORO3ENZOYL)-3- (6- (3- (TRIFLUORO-METHYLPHENYLTHIO)-3-PYRIDINYL)THIOUREA
6- (3- (Trifluoromethyl)phenylthio)-3-aminopyridine (1.0 gram) and 2-chlorobenzoyl iso-thiocyanate (1.0 gram) were mixed in 50 ml~ of ethyl acetate and stirred overnight (about 18 hours) at 10 room temperature. Solvents were then removed by evaporation and the product residue was crystallized from ethyl acetate-hexanes, m.p. 134-137C., yield 1.7 grams.
Calc. for C20EI13ClF3N3OS2: C, 51.34; H, 2.80;
N, 8.9~
Found: C, 51.35; H, 2.93;
~, 9~06 EXAMPLE 14: 2-NITRO-5-CHLOROPYRIDINE
2-Amino-5-chloropyridine (50 grams) was 20 added portionwise to a solution or 300 ml. of con-centrated H2SO4 and 150 ml. of 30% H2O2, maintainedat a temperature of 0-5C., over a period of 5.0 hours. The reaction mixture was then allowed to rise to room temperature and stirred at room temperature 25 for 24 hours. The reaction mixture was then poured over ice, and the product residue separated by filtratior~ and air dried. Crystallization from ethyl acétate-ethanol gave only the azo compound. The remainder of the product residue was passed over a 30 column of silica gel with a mixture of 1:1 toluene:-~l 3:1232 eth~l acetate. The desired product was isolated and its identity confirmed by NMR.
EX~PLE lS: 2-NITRO-S-(4-CHLOROPHENYLTHIO)PYRIDINE
2-Nitro-5-chloropyridine (9.S grams), 4-chlorothiophenol (8.7 grams), and lithium hydroxide (4 grams) were mixed in 100 ml. of DMF and the reaction mixture was stirred overnight (about 18 hours) at room temperature. The reaction mixture was then poured into water and the produc~ separated by filtration and crystallized from ethanol-hexanes, yield, 10.0 grams, m.p., 96-98C.
Calc. for CllH7ClN2O2S: C, 49.54; H, 2.65; N, 10-50-Found: C, 49.31; H, 2.88; N, 10.38.
EXAMPLE 16: 2-~MINO-5-(4-CHLOROPHENYLTHIO)PYRIDINE
2-Nitro-5-(4-chlorophenylthio)pyridine (10.5 grams), ammonium chloride (50.0 grams), and powdered iron (30.0 grams) were reacted in the same procedures reported in Example 3. The reaction mixture was filtered hot solvents were removed. The product was extracted with e~hyl acetate, washed with water, the ethyl acetate removed, and the product crystallized from ethyl acetate-hexanes, yield 4.5 grams, m.p. 157-159C.
Calc. for CllHgClN2S: C, 55.81; H, 3.83; N, 11.83.
Found: C, 55.97; H, 3.88; N, 11.57.
EXAMPLE li: 2-AMINO-5-BROMOPYRIDINE
Bromine (240 grams) was added dropwise to a solution of 2-aminopyridine (141 grams) in 1 liter of ~ . . . .

~ .

acetic acid, maintaining the temperature at 0C.
After the completion of the addition, the ~emperature of the reaction mixture was raised to 50C. and the reaction mixture stirred for one hour at that tem~
perature, then poured into water. The precipitate was separated by filtration, and the reaction mixture neutralized with concentrated NaOH and a second precipitate separated by filtration.
NMR established that the first precipitate was 2-amino~3,5-dibromopyridine, whereas the second precipitate was the desired 2-amino-5-bromopyridine, yield, 100 grams, m.p., 130-132C. (lit. ref., Or~.
Svn. Coll. 5, supra, m.p., 132-135C).
-EXAMPLE 18: 2-AMINO-5-(4-CHLOROPHENYLTHIO)PYRIDINE

2-Amino-5-bromopyridine (7.8 grams), 4-chlorothiophenol (9.2 grams), sodium methoxide (3.5 grams), and copper powder (1.0 gram) were reacted in 100 ml. of methanol, for 12 hours, in a bomb, in accordance with ~he procedures of J. Med. Chem. 21, 235 (1978). The reaction mixture was filtered, washed with methanol, and methanol removed by evap-oration. The methanol washes were combined with ethyl acetate extracts of solids made after refluxing on a steam bath for one hour. Solvents were removed and the solids dissolved in ethyl acetate and fil-tered to remove insolubles. The liquid was passed over a silica column with ethyl acetate, and the fra~tion corresponding to the product amine (R~ -300.2) collected., yield 6~5 grams, m.p., 161-163C.

~3~3~

Calc- for CllH9ClN2S C, 55.81; H, 3.83; N, 11.83.
Found: C, 55.87; H, 4.02; N, 11.83.
Other representative compounds of the present invention include the following.

~13~LZ3Z

~1~ ! , _ o , ~_ ~D -~1 ~
~ S~ O
~O
~ O r~l S
l l I I
_ ~ I
I X X
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S ~ ~ .C
'- Q~
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X O X ,~
O ~ O ~ ~ -~
.C ~J .C I I
J~
a~
1 5 E~
.,~ ~ .,, _ _ ", I ~ ~ ~ _ ~ I In Z
~ _ C
o Q I
E~ ~ I 1'') N N O
20o ~ _ ~ c: ~ N
c~ ~

:~ O :>~ ~ ~ Q
O N O X X O
N ~ N O O h ~ .1 ~ O
C~ Q O ~
X ~ E~
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5~ I h ~. J S ~ O ~O 1 0 ~
C.~ ^ h--~ ~ O ~O ~ O ~
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I C I ~ I C S
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F~ L'l Ln U') ~)Il')li') ~ N ~I ~ ~ ~ ~
~i 3~Z3Z -, The compounds of the present invention are useful for the control of insects of various orders, including Coleoptera such as ~e~ican bean beetle, boll weevil, corn rootworms, cereal leaf beetle, flea -~
beetles, borers, Colorado potato beetle, grain beetles, alfalfa weevil, carpet beetle, confused flour beetle, pcwder post beetle, wireworms, rice weevil, rose beetle, plum curculio, white grubs; Diptera, such as house fly, yellow fever mosquito, stable fly, horn fly, blowfly, cabbage maggot, carrot rust fly;
Lepidoptera, such as southern armvworm, codling moth, ..
cutworm, clothes moth, Indian meal moth, leaf rollers, corn earworm, European corn borer, cabbage worm, cabbage looper, cotton bollworm, bagworm, eastern tent caterpillar, sod webworm, fall armyworm; and Ortho~tera, such as German co~kroach and American cockroach.
The compounds of the present invention are additionally useful for the control of other insects such as common cattle grub, face fly, mosquitoes, spruce bud worm, bollworms, tabanid fly~ tobacco budworm, armyworms including beet armyworm ana yellow striped armyworm, South-western corn borer, potato leafhopper, lesser cornstalk borer, grasshoppers, cotton fleahopper, wheat stem sawfly, horse fly, webworms, maggots, velvetbean caterpillar, pecan weevil, whitefringed beetle, pecan nut casebearer, pink bollworm, darkling beetle, hickory shuckworm, walnut cater pillar, tobacco hornworm, loopers, Egyptian cotton leaf-worm, co¢kroaches, green cloverworm, alfalfa caterpillar, co'rn leaf beetle, leaf miner fly, diamondback moth, rednecked peanut worm, stalk borer, cigarette beetle, 3~23~

sunflower moth, tomato pinworm, oriental fruit moth, peachtree borer, melon fly, imported cabbase worm, lesser peachtree borer, grape root borer, black fly, pepper weevil, threestriped blister beetle, sunflower beetle, nose bot fly, grape berry moth, sheep ked, and leaf rollers.
It is believed that the present compounds act by interfering with the mechanism of metamorphosis which occurs in insects, causing the death of the insects. It is also believed that ingestion by the insects is necessary to invoke this mechanism. While the death of any given insect may be delayed until that insect reaches some stage of metamorphosis, the net result of this activity is the control and suppression of insects.
Therefore, in another embodiment, the present invention is directed ~o a method of sup-pressing insects which comprises applying to a locus of the insects an effective amount of a compound of the present invention. The locus can be any environ-ment inhabited by insects to be controlled, such as soil, air, water, foods, vegetation, manure, inert objects, stored matter such as srain, and the like.
Preferably the compounds of the present invention are supplied in a formulation, for ease of application. The compounds can be formulated with various adjuvants, including water, orsanic liquids, surface-active agents, inert solids, and the like.
Sultable surface-active agents include anionic agents, such as sodium lauryl sulfate, sodium dodecylbenzene-~3~;Z3Z
) .

sulfonate, and the like; and nonionic agents, such as polyethylene glycol p-nonylphenyl ether. Mixtures are often desirably employed. The formulation can take the form of a liquid, dust, granule, aerosol, etc.
The formulation can be concentrated, as in a slow release formulation or as in a formulation to be diluted with water before application to the locus of insects. Many methods of formulation are known in the art and can be employed to implement the present invention.
The concentration of active agent in the formulation is not critical, inasmuch as an effective concentration will vary with the nature of the locus to be treated~ the severity of insect infestation, the susceptibili~y of the particular insects involved, etc. In general, concentrations ranging from about 0.1 to 1000 ppm give good results. As exemplified by Table 2, below, lesser concentrations of from about 1 to about 100 ppm have given good control of southern armyworm.
The insecticidal activity of the present compounds was determined by testing the efficacy of formulations of the compounds against Mexican bean beetle larvae tEpilachna varivestis), and against southern armyworm larvae (Spodoptera eridania). These insects are members of the Coleoptera and Lepidoptera orders of insects, respectively. The formulations were applied to the foliage of plants and the larvae werie subsequently permitted to feed on the foliage.
The compounds were tested in a plurality of concen-trations, from a concentration of about 1000 ppm. to about 1 ppm.

~L~3~Z32 Each compound to be tested was formulated by dissolving 10 mg~ of the compound in 1 ml. of a solvent made up with 23 grams of Toximul R and 13 srams of Toximul S per liter of 1:1 anhydrous ethanol and acetone. Each of Toximul R and Toximul S is a sulfonate/nonionic blend produced by Stepan Chemical Company, Northfield, Illinois. Water was then added to obtain 10 ml. of solution containing the compound in a concentration of 1000 parts per million. Alter-natively, 11 mg. of compound was used, to make up11 ml. of solution, of which 10 ml. was employed as a 1000 ppm. treating solution, and of which the re-maining 1 ml. was diluted further with water to obtain a treating solution containing 100 ppm. of compound.
Formulations of th~ compound at lesser concentrations were prepared in the same manner, using the same solvent.
Each solution of test compound was sprayed onto two 4-inch square pots of bean plants containin~
6 to 10 plants per pot. The plants were allowed to dry and then 12 leaves were removed and the cut ends wrapped in water-soaked cellucotton. The leaves were divided between six 100 x 20 mm. plastic petri dishes.
Five second-instar Mexican bean beetle larvae (Epilachna varivestis) and five second- and third-instar southern armyworm larvae ( ~ eridania) were placed in each of three dishes. The dishes were th~'n placed in a room wherein the temperature and relative humidity were controlled at about 78F. and about 51 percent, respectively, for a period of four ~3~23;2 days, at which time the first evaluation of the effects of the test compounds was made. After this evaluation, two fresh leaves from the orisinal treated pots were placed in each dish. The dishes were again maintained in the temperature and humidity controlled room for an additional three days until the ~inal seven-day evaluation was made.
Xnsecticidal effect was determined by countins the number of living larvae of each species, and applying the following rating code:
0 = all larvae livins 1 = half or more than half of the larvae livins 2 = less than half of the larvae living ~ 3 = all larvae dead The results of this test are set forth in Table 1, which follows. In the table, column 1 identifies the compounds by the number of the prep-arative example; column 2 lists the concentration of the test compound in the formulation; and columns 3 through 6 give the rating code at days 4 and 7 for the two insects against which the compounds were tested.

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Many of the compounds of the present in-vention were also tested in the same procedure described above but at lower concentrations. In these tests, percent control was determined by counting the number of living larvae per dish and using Abbott's formula [W. W. Abbott, "A Method of Computing the Effectiveness of an Insecticide", J. Econ. Entomol.
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Percent Control = 0 No. of survivors in control - No. of survivors in treatment x 100 No. survivors in control The results are set forth in Tables 2A and 2B, which follow.

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Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Compound of the formula wherein each R is independently chloro, fluoro, methyl, or methoxy.

2. The compound of Claim 1, which is 1-(2,6-dichlorobenzoyl)-3-(6-(3,5-dimethoxyphenoxy)-3-pyridinyl)urea.

3. The compound of Claim 1, which is 1-(2,6-dimethoxybenzoyl)-3-(6-(3,5-dimethoxyphenoxy)-3-pyridinyl)urea.

4. The compound or Claim 1, which is 1-(2,6-difluorobenzoyl)-3-(6-(3,5-dimethoxyphenoxy)-3-pyridinyl)urea.

5. The compound of Claim 1, which is 1-(2-chloro-6-methoxybenzoyl)-3-(6-(3,5-dimethoxy-phenoxy)-3-pyridinyl)urea.

6. The compound of Claim 1, which is 1-(2-fluoro-6-methoxybenzoyl)-3-(6-(3,5-dimethoxy-phenoxy)-3-pyridinyl)urea.

7. The compound of Claim 1, which is 1-(2-chloro-6-fluorobenzoyl)-3-(6-(3,5-dimethoxy-phenoxy)-3-pyridinylurea.

8. Method of suppressing insects of an order selected from the group consisting of Coleoptera, Diptera, Lepidoptera, and Orthoptera, which comprises applying to the locus of the insects an effective amount of an active agent which is a compound of Claim 1.

9. The method of Claim 8, in which the active agent is 1-(2,6-dichlorobenzoyl)-3-(6-(3,5-dimethoxyphenoxy)-3-pyridinyl)urea.