GB1573905A

GB1573905A - Heterocyclic oximes and their use as pesticides

Info

Publication number: GB1573905A
Application number: GB1274576A
Authority: GB
Original assignee: SHELL INT RESEARCH; Shell Internationale Research Maatschappij BV
Current assignee: SHELL INT RESEARCH; Shell Internationale Research Maatschappij BV
Priority date: 1976-03-30
Filing date: 1976-03-30
Publication date: 1980-08-28
Also published as: CH630639A5; FR2346341B1; FR2346341A1; JPS52118469A; NL7703312A; BR7701923A; AU2367877A; MX4882E; DE2713609A1; BE852776A; AU509052B2; CA1084495A

Abstract

The oximes of the general formula I whose symbols have the meaning given in Claim 1 have interesting insecticidal and acaricidal properties, in particular with regard to the Egyptian cotton leafworm. These compounds are prepared by nitrosating an appropriate enamine. <IMAGE>

Description

(54) HETEROCYCLIC OXIMES AND THEIR USE AS PESTICIDES (71) We, SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V., a company organised under the laws of The Netherlands, of 30 Carel van Bylandtlaan, The Hague, The Netherlands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be particularly described in and by the following statement:- The present invention relates to novel heterocyclic oximes to be specified hereinafter, as well as to a method of their preparation. The heterocyclic oximes according to the present invention have interesting pesticidal, especially insecticidal and acaricidal properties. The present invention therefore also relates to pesticidal compositions comproperties. The present invention therefore also relates to pesticidal compositions comprising a carrier or a surface active agent or both a carrier and a surface active agent and at least one heterocyclic oxime to be specified hereinafter. The present invention also relates to a method of combating pests by applying to a locus a heterocyclic oxime according to the present invention or a composition comprising at least one heterocyclic oxime according to the present invention.

The novel compounds according to the present invention are heterocyclic oximes of the general formula:

wherein n=2, 3 or 4; X represents oxygen, sulphur, NR wherein R represems a hydrogen atom or an alkyl, alkenyl, alkynyl, haloalkyl, aryl, alkaryl or aralkyl group or CR2RS wherein R2 and R3 each individually represents a hydrogen or halogen atom, or an alkyl group or wherein R2 and R3 together with the carbon atom to which they are attached form a ring structure which may contain one or more hetero atoms in the ring; Y represents a hydrogen atom or an alkyl, haloalkyl, cyanoalkyl, carboxylic acid acyl, or optionally substituted carbamoyl group

wherein R4 and R5 each individually represents hydrogen or alkyl and Rl represents a hydrogen atom or an alkyl, cycloalkyl, haloalkyl, alkoxy, or aryloxy group or an aryl group optionally substituted by one or more halogen atoms, nitro groups or alkyl or alkoxy groups or fused with a heterocyclic or carbocyclic ring, or a heterocyclic ring system or an optionally substituted amino group and which include, when Y represents a hydrogen atom, the tautomeric form represented by the formula:

Preferred heterocyclic oxinaes are those represented by formula I wherein n=2 or 3; X represents sulphur or NR wherein R represents a hydrogen atom or an alkyl, alkenyl or haloalkyl group of up to 6 carbon atoms; Y represents a hydrogen atom or an alkyl, haloalkyl or carboxylic acid acyl group of up to 7 carbon atoms or a carbamoyl group and R1 represents an alkyl, haloalkyl or alkoxy group of up to 6 carbon atoms or an aryloxy group or a phenyl group substituted with one or more halogen atoms, nitro groups or alkyl or alkoxy groups with up to 6 carbon atoms or a nitrogen-containing heterocyclic ring system.

More preferred heterocyclic oximes according to the present invention are those according to formula I wherein n=3; X represents sulphur; Y represents a hydrogen atom or a carboxylic acid acyl group of up to 7 carbon atoms or a carbamoyl group and R1 represents a phenyl group substituted by up to three chlorine or bromine atoms or a pyridine group, for example, 2 - (1 - (3,4 - dichlorobenzoyl) - 1 - hydroxyiminomethyl) - 5,6 - dihydro - 4H - 1,3 - thiazine, 2 - (1 - (4 - pyridoyl) - 1 - hydroxy iminomethyl) - 5,6 - dihydro - 4H - 1,3 - thiazine, 2 - (1 - (3 - pyridoyl) - 1hydroxyiminomethyl) - 5,6 - dihydro - 4H -1,3 - thiazine.

The heterocyclic oximes can exist in several isomeric forms, such as cis-configuration, trans-configuration and mixtures thereof which are within the scope of the present invention.

The heterocyclic oximes according to the present invention may be prepared by a process which comprises nitrosation of the corresponding enamines in the presence of an acid according to the equation:

wherein n, X, and R1 have the meanings as specified hereinabove. The reaction can be suitably carried out by using acetic acid or a dilute mineral acid such as hydrochloric acid. Sodium nitrite can be suitably used but other nitrites normally applied in nitrosation reactions can be used as well. The reaction is conveniently carried out at moderate temperatures, preferably in the range of from 5 C to 15 C. The acid employed may also serve as the solvent. A mixture of solvents can also be employed.

Derivatives of the heterocyclic oximes can be prepared using conventional methods.

As mentioned hereinbefore, the heterocyclic oximes according to the present invention are of interest as pesticides. They show a promising activity against the Egyptian cotton leafworm (Spodoptera littoralis). The present invention therefore includes pesticidal compositions comprising a carrier and/or a surface active agent together with at least one heterocyclic oxime according to formula I. Likewise the present invention also includes a method of combating pests at a locus which comprises applying to the locus a heterocyclic oxime or a composition comprising at least one heterocyclic oxime according to the present invention.

The term 'carrier' as used herein means a solid or fluid material, which may be inorganic or organic and of synthetic or natural origin, with which the active compound is mixed or formulated to facilitate its application to the plant, seed, soil or other object to be treated, or its storage, transport or handling.

The surface active agent may be an emulsifying agent or a dispersing or a wetting agent; it may be non-ionic or ionic.

Any of the carrier materials or surface-active agents usually applied in formulating pesticides may be used in the compositions of the invention, and suitable examples of these are to be found, for example, in British Patent Specification No. 1,232,930.

The compositions of the invention may be formulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates or aerosols. Wettable powders are usually compounded to contain 25, 50 or 75% of toxicant and usually contain, in addition to solid carrier, 310%w of a dispersing agent and, where necessary, O-10%w of stabilizer(s) and/or additives, such as penetrants or stickers.

Dusts are usually formulated as a dust concentrate having a similar composition to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing 0.510%w of toxicant. Granules are usually prepared to have a size between 10 and 100 BS mesh (1.676-0.152 mm), and may be manufactured by agglomeration or impregnation techniques. Generally, granules will contain 0.5-25%w toxicant and 0-10%w of additives such as stabilizers, slow release modifiers and binding agents. Emulsifiable concentrates usually contain, in addition to the solvent and, when necessary, co-solvent, 10-50% w/v toxicant, 2-20% w/v emulsifiers and 0-20% w/v of appropriate additives such as stabilizers, penetrants and corrosion inhibitors. Suspension concentrates are compounded so as to obtain a stable, non-sedimenting, fiowable product and usually contain 10-75%w toxicant, 0.5-15%w of dispersing agents, 0.1-10%w of suspending agents such as protective colloids and thixotropic agents, 0-10%w of appropriate additives such as defoamers, corrosion inhibitors, stabilizers, penetrants and stickers, and as carrier, water or an organic liquid in which the toxicant is substantially insoluble; certain organic solids or inorganic salts may be dissolved in the carrier to assist in preventing sedimentation or as anti-freeze agents for water.

Aqueous dispersions and emulsions, for example compositions obtained by diluting a wettable powder or a concentrate according to the invention with water, also lie within the scope of the present invention. The emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick 'mayonnaise'-like consistency.

The compositions according to the invention may also contain other ingredients, for example, other compounds possessing pesticidal, especially insecticidal, acaricidal, herbicidal or fungicidal properties.

The invention is further illustrated in the following Examples: EXAMPLE 1.

Preparation of 2(1 - (3,4 - dichlorobenzoyl) - 1 - hydroxyiminomethyl) 5,6 - dihydro - 4H - 1,3 - thiazine 1' - (Hexahydro - 1,3 - thiazin - 2 - ylidene) - 3,4 - dichloroacetophenone (28.8g, 0.1M) was suspended in water (250 ml) and adjusted to about pH 2.0 with dilute hydrochloric acid. The suspension was cooled to between 50C and 10 C and sodium nitrite (13.8g, 0.2M) in water (30 ml) was added slowly with stirring, maintaining temperature and pH. The reaction mixture was stirred for 2 hours. Diluted sodium hydroxide was added until about pH 6, followed by an excess of sodium bicarbonate.

The product obtained was filtered off and recrystallised from methanol. Yield 30.lg (95%). m.p. 178-1800C.

Analysis: Calculated for Cl2Hl O2N2SCI2: C 45.4; H 3.2; N 8.8; Cl 22.4% Found : C 45.0; H 3.1; N 8.5; Cl 23.0% EXAMPLE 2.

Preparation of 2(1 - (4 - chlorobenzoyl) - 1 - hydroxyiminomethyl) 1,4,5,6 - tetrahydro - 1 - methylpyrimidine To a stirred solution of 1' - (hexahydro - 1 - methylpyrimidin - 2 - ylidene)4 - chloroacetophenone (3.5g, 0.01M) in acetic acid (25 ml) was added sodium nitrite (1.9g, 0.028M) in water (10 ml). The mixture was stirred during 3 hours at a temperature below 30"C. The reaction mixture was then poured into water and an excess of sodium bicarbonate added. The mixture was extracted with chloroform and the product obtained after removal of chloroform was recrystallized from a mixture of chloroform/hexane. The yield was 3.1 g (79%). m.p. 154--15S"C.

Analysis: Calculated for C13H14O2N3Cl1: C 55.8; H 5.0; N 15.0% Found : C 55.3; H 5.0; N 14.4% EXAMPLE 3.

Preparation of 2(1 - (3,4 - dichlorobenzoyl) - 1 - methylcarbamoyloxy iminomethyl) - 5,6 - dihydro - 4H - 1,3 - thiazine 2(1 - (3,4 - Dichlorobenzoyl) - 1 - hydroxyiminomethyl) - 5,6 - dihydro - 4H1,3 - thiazine (1.0g) was dissolved in dichloromethane (25 ml) and methyl isocyanate (1 ml) was then added slowly followed by 1 drop of triethylamine. The reaction mixture was stirred for two hours at ambient temperature. After removal of the solvent, the product was passed through a column containing silica-gel using chloroform as eluent. The yield was 0.8g (79%). m.p. 141--143 OC.

Analysis: Calculated for C14H1,O3N,SCl2: C 44.9; H 3.5; N 11.2% Found : C 45.1; H 3.6; N 11.0% EXAMPLE 4.

Preparation of 2(1 - methoxycarbonyl - 1 - hydroxyiminomethyl) 5,6 - dihydro - 4H - 1,3 - thiazine Methylhexahydro - 1,3 - thiazin - 2 - ylidene acetate (8.7g, 0.05M) was suspended in water (250 ml) and adjusted to about pH 2 with dilute hydrochloric acid.

The suspension was cooled to between 5"C and 10 C and sodium nitrite (6.9g, 0.1M) in water (10 ml) was added slowly maintaining the temperature and the pH. The reaction mixture was stirred for two hours. Dilute sodium hydroxide was added to about pH 6, followed by an excess of sodium bicarbonate. The product was extracted with choroform, the solvent removed and the solid recrystallized from methanol/water.

Yield 8.8g (88%). m.p. 121--123"C.

Analysis: Calculated for C,H1003N2S: C 41.6; H 4.9; N 13.9% Found C 41.6; H 5.0; N 13.7% EXAMPLE 5.

Preparation of 2(1 - (3,4 - dichlorobenzoyl) - 1 - acetoxyiminomethyl 5,6 - dihydro - 4H - 1,3 - thiazine A sofution containing 2(1 - 3,4 - dichlorobenzoyl) - 1 - hydroxyiminomethyl)5,6 - dihydro - 4H - 1,3 - thiazine (3.2g, 0.01M) in dry DMF (10 ml) was added to a stirred suspension of sodium hydride (0.24g, 0.01M) in DMF (15 ml). Keeping the temperature below 100C by cooling in an ice-water bath. Keeping the reaction mixture at the same temperature, a solution of acetyl chloride (0.8g, 0.01M) in DMF (10 ml) was then added, with stirring, over a period of 15 minutes. After stirring for 3 hours, water (300 ml) was added and the product was extracted with chloroform.

The chloroform extract was dried (MgSO) and evaporated to yield the crude acetate which was recrystallised from diethyl ether. Yield 1.8g (50%) m.p. 111-1130C.

Analysis: Calculated for C14H12O3N2SCl2: C 46.8; H 3.3; N 7.8; Cl 19.8% Found C 47.7; H 3.7; N 7.8; Cl 20.7% EXAMPLES 6-19, 21, 23 and 24.

Following procedures similar to those described in the foregoing Examples, further compounds according to the invention were prepared. The physical characteristics and analytical data are set out in Table I below.

TABLE I

Yield Example Compound m.p. ( C) (%) Analysis 6 2(1-ethoxycarbonyl-1-hydroxyimino- 134-6(dec) 65 Calculated for C8H12O3N2S : C 44.4; H 5.6; N 12.9% methyl)-5,6-dihydro-4H-1,3-thiazine Found : C 44,8; H 5.6; N 13.2% 7 2(1-(4-chlorobenzoyl)-1-hydroxyimino- 153-4(dec) 46 Calculated for C12H11O2N2SCl : C 51.0; H 3.9; N 9.9% methyl)-5,6-dihydro-4H-1,3-thiazine Found : C 51.3; H 4.1; N 9.6% 8 2(1-benzoyl 1-hydroxyiminomethyl)- 192-194 41 Calculated for C12H12O2N2S : C 58.1; H 4.8; N 11.3% 5.6-dihydro-4H-1,3-thiazine Found : C 58.9; H 5.1; N 11.2% 9 2(1-acetyl-1-hydroxyiminomethyl)- 120-122 36 Calculated for C7H10O2N2S : C 45.2; H 5.4, N 15.1% 5,6-dihydro-4H-1,3-thiazine Found : C 45.5; H 5.5; N 15.0% 10 2(1-propionylmethyl-1-hydroxyimino- 132-134 85 Calculated for C8H12O2N2S : C 45.0; H 6.0; N 14.0% methyl)-5,6-dihydro-4H-1,3-thiazine Found : C 47-1; H 6.0; N 13.8% 11 2(1-(2,4-dichlorobenzoyl)-1-hydroxy- 108-111 80 Calculated for C12H10O2N2SCl2 : C 45.4; H 3.2; N 8.8; Cl 22.4% iminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 45.7; H 3.2; N 8.7; Cl 22.1% 12 2(1-(2,3,4-trichlorobenzoyl)-1-hydroxy- 135-136 89 Calculated for C12H9O2N2SCl3 : C 41.0; H 2.6; N 8.0; Cl 30.3% iminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 41.0; H 2.5; N 8.8; Cl 30.2% TABLE I (Continued)

Yield Example Compound m.p. ( C) (%) Analysis 13 2(1-(3-chlorobenzoyl)-1-hydroxyimino- 181-183 92 Calculated for C12H11O2N2SCl ; C 51.0; H 3.9; N 9.9; Cl 12.5% methyl)-5,6-dihydro-4H-1,3-thiazine Found : C 50.6; H 3.8; N 9.7; Cl 12.8% 14 2(1-(4-bromobenzoyl)-1-hydroxyimino. 173-174 71 Calculated for C12H11O2N2SBr : C 44.0; H 3.4; N 8.6; Br 24.5% methyl)-5,6-dihydro-4H-1,3-thiazine 5,6-dihydro-4H-1,3-thiazine Found : C 44.0; H 3.4; N 8.2; Br 24.7% 15 2(1-(3,4-dichlorobenzoyl)-1-methoxy 111-113 67 Calculated for C13H12O2N2SCl2 : C 47.1; H 3.6;N 8.5; Cl 21.5% iminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 46.9; H 3.9; N 8.1; Cl 21.3% 16 2(1-(3,4-dichlorobenzoyl)-1-benzoyl- 153-155 43 Calculated for C19H14O3N2SCl2 : C 54.2; H 3.3; N 6.7% oxyiminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 54.0; H 3.3; N 6.6% 17 2(1-(2-thienoyl)-1-hydroxyimino- 119-122 62 Calculated for C10H10O2N2S2 : C 47.2; H 3.9; N 11.0% methyl)-5,6-dihydro-4H-1,3-thiazine Found : C 47.8; H 4.1; N 10.2% 18 2(1-(2-furoyl)-1-hydroxyimino- 144-146 88 Calculated for C10H10O3N2S : C 50.4; H 4.2; N 11.8% methyl)-5,6-dihydro-4H-1,3thiazine Found : C 51.4; H 4.5; N 11.7% 19 2(1-t-butyloxycarbonyl-1-hydroxy- 157-158 66 Calculated for C10H15O3N2S : C 49.2; H 6.6; N 11.5% iminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 49.3; H 6.8; N 11.0% TABLE I (Continued)

Yield Example Compound m.p. ( C) (%) Analysis 21 2(1-(4-chlorobenzoyl)-1-hydroxy- 79-82 80 Calculated for C12H12O2N3Cl : C 54.2; H 4.5; N 15.8% iminomethyl)-1-methyl-2-imidazoline Found : C 53.4; H 4.8; N 5.9% 23 2-(1-(4-fluorobenzoyl)-1-hydroxy- 163-165 95 Calculated for C12H11O2N2SO2 : C 54.1; H 4.2; N 10.5% iminomethyl)-5,6-dihydro-4H-1,3thiazine Found : C 54.9; H 4.4; N 10.1% 24 2-(1-m-toluyl)-1-hydroxyimino- 175-177 77 Calculated for C13H14H14N2SO2: C 59.5; H 5.4; N 10.7% methyl)-5,6-dihydro-4H-1,3thiazine Found : C 59.8; H 5.4; N 10.7% EXAMPLE 20.

Preparation of 2 - (1 - (3 - pyridoyl) - 1 - hydroxyiminomethyl)5,6 - dihydro - 4H - 1,3 - thiazine (Hexahydro - 1,3 - thiazine - 2 - ylidene) - 3 - pyridylketone (11.0g, 0.05M) was suspended in water (200 ml) and the pH adjusted to about 2.0 with dilute hydrochloric acid (5N). The suspension was cooled to below 10 C and sodium nitrite (6.9g, 0.1M) in water (25 ml) was added slowly with stirring, maintaining the pH at 2.0. The reaction mixture was stirred for 2 hours. Dilute sodium hydroxyde was added until pH 6.0, followed by excess of sodium bicarbonate. The mixture was extracted with chloroform and the product obtained after removal of chloroform was recrystallised from methanol. Yield 9.0g (73%). m.p. 177-178 C.

Analysis: Calculated for C11H11O2N2S: C 53.0; H 4.4; N 16.9% Found : C 53.0; H 4.4, N 16.9% EXAMPLE 22.

Preparation of 2 - (1 - (4 - pyridoyl) - 1 - hydroxyiminomethyl)5,6 - dihydro - 4H - 1,3 - thiazine (Hexahydro - 1,3 - thiazine - 2 - ylidene) - 4 - pyridylketone (6.6g, 0.03M) was suspended in water (200ml) and the pH adjusted to about 2.0 with dilute hydrochloric acid (5N). The suspension was cooled to between 5 and 10 C and sodium nitrite (4.1g, 0.06M) in water (25 ml) was then added slowly, over 20 minutes, with stirring, whilst maintaining the pH at 2.0. The reaction mixture was stirred for 2 hours. Dilute sodium hydroxide was added until pH 6.0, followed by excess sodium bicarbonate. The product was extracted with chloroform and after removal of chloroform the product was recrystallised from methanol/water 1:1. Yield 6.9g (93%). m.p. 173-1740C.

Analysis: Calculated for CllHllOgN2S: C 53.0; H 4.4; N 16.9% Found : C 52.5; H 4.4; N 16.8% The compounds were formulated as solutions or suspensions in water containing 20% by weight of acetone and 0.05% by weight of Triton-X-i00 ("Triton" is a registered trade mark) as wetting agent. The formulations contained 0.4% by weight of the compounds to be tested. Pairs of leaves are removed from broad bean plants and placed on filter paper inside plastic petri-dishes. The leaves are sprayed using a spraying machine operated on the conveyor belt principle. The dosage is equivalent to 340 litres/hectare. After spraying the leaves are left for a drying period and then each leaf pair is infested with 10 larvae. Throughout the test the larvae are held under normal glasshouse conditions, fluctuating humidity and light. The number of dead and moribund insects is counted after 24 hours.

The results of the test are shown in Table II, in which A denotes greater than 80% kill, B 30-80% kill and C less than 20% kill.

TABLE II

RATING EXAMPLE A 1, 3, 4, 10, 12, 13, 14, 18, 20, 22 B 5, 7, 9, 11, 23, 24 C 2, 8, 15, 16, 17, 19

Claims

WHAT WE CLAIM IS:1. Heterocyclic oxmines of the general formula:

wherein n=2, 3 or 4; X represents oxygen, sulphur, NR wherein R represents a hydrogen atom or an alkyl, alkenyl, alkynyl, haloalkyl, aryl, alkaryl or aralkyl group or CR2R:- wherein R2 and R3 each individually represents a hydrogen or halogen atom, or an alkyl group or wherein R2 and R3 together with the carbon atom to which they are attached form a ring structure which may contain one or more hetero atoms in the ring; Y represents a hydrogen atom or an alkyl, haloalkyl, cyanoalkyl, carboxylic acid acyl, or optionally substituted carbamoyl group

wherein R-; and R3 each individually represents hydrogen or alkyl and R1 represents a hydrogen atom or an alkyl, cycloalkyl, haloalkyl, alkoxy, or aryloxy group or an aryl group optionally substituted by one or more halogen atoms, nitro groups or alkyl or alkoxy groups or fused with a heterocyclic or carbocyclic ring, or a heterocyclic ring system or an optionally substituted amino group and which include, when Y represents a hydrogen atom, the tautomeric form represented by the formula:
2. Heterocyclic oximes as claimed in claim 1 wherein n=3 and X represents sulphur.
3. Heterocyclic oximes as claimed in claim 1 or 2 in which Y represents a hydrogen atom or a carboxylic acid acyl group of up to 7 carbon atoms or a carbamoyl group.
4. Heterocyclic oximes as claimed in claim 1, 2 or 3 in which R1 represents a phenyl group substituted by up to three chlorine or bromine atoms or a pyridine group.
5. 2 - (1 - (3,4 - dichlorobenzoyl) - 1 - hydroxyiminomethyl) - 5,6 - dihydro 4H - 1,3 - thiazine.
6. 2 - (1 - (4 - pyridoyl) - 1 - hydroxyiminomethyl) - 5,6 - dihydro - 4H - 1,3thiazine.
7. 2 - (1 - (3 - pyridoyl) - 1 - hydroxyiminomethyl) - 5,6 - dihydro - 4H1,3 - thiazine.
8. A heterocyclic oxime as claimed in claim 1 and as described in any one of the examples 1 to 22.
9. A heterocyclic oxime as claimed in claim 1 and as described in Example 23 or 24.
10. A process for the preparation of heterocyclic oximes according to any one of claims 1 to 7 wherein Y represents a hydrogen atom, which comprises nitrosation of an enamine in the presence of an acid according to the equation:-

wherein n, X and R1 have the meanings defined in claim 1.
11. A process according to claim 9 substantially as described with reference to any one of Examples 1, 2, 4, 20 and 22.
12. A heterocyclic oxime prepared by a process according to claim 10 or 11.
13. Pesticidal compositions comprising a carrier and/or a surface-active agent together with, as active ingredient, at least one heterocyclic oxime as claimed in any one of claims 1 to 9 or claim 12.
14. A method of combating insect pests at a locus, which comprises applying to the locus a heterocyclic oxime as claimed in any one of the claims 1 to 7 and 12, or a composition as claimed in claim 13.