GB1581675A

GB1581675A - Fungicidal phenylhydrazones

Info

Publication number: GB1581675A
Application number: GB22755/77A
Authority: GB
Original assignee: Shell Internationale Research Maatschappij BV
Current assignee: Shell Internationale Research Maatschappij BV
Priority date: 1977-05-30
Filing date: 1977-05-30
Publication date: 1980-12-17
Also published as: JPS6138185B2; DE2823362A1; FR2392985A1; FR2392985B1; BE867584A; CH637920A5; NL7805805A; PH14215A; DE2823362C2; IT1094867B; BR7803419A; IT7823934A0; OA05974A; JPS53149941A

Abstract

The active substances are N-formylphenylhydrazones of the general formula: <IMAGE> in which R is an optionally substituted phenyl, thienyl, furyl or pyridyl group; R<1> is an alkyl, phenyl or cycloalkyl group, X is a hydrogen or halogen atom or an alkyl or alkoxy group, and n is 0, 1 or 2. They possess fungicidal properties.

Description

(54) FUNGICIDAL PHENYLHYDRAZONES (71) We, SHELL INTERNATION- ALE RESEARCH MAATSCHAPPIJ B.V., a company organized 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 performed, to be particularly described in and by the following statement: This invention relates to N-formyl-phenylhydrazones which are useful for protection of crops from fungi.

The present invention provides N-formylphenylhydrazones of general formula: -

wherein R represents an optionally substituted phenyl, thienyl, furyl or pyridyl group; R1 represents an alkyl, phenyl or cycloalkyl group; X represents a hydrogen or a halogen atom or an alkyl or alkoxy group and n represents 0, 1 or 2.

Preferred compounds of the invention are those of formula (I) wherein R represents a phenyl, thienyl or furyl group, each of which may be substituted by an alkyl group, particularly an alkyl group containing 1 to 4 carbon atoms especially a methyl group or a halogen atom, e.g. a chlorine, fluorine or bromine atom; R1 represents an alkyl group containing 1 to 4 carbon atoms, for example a methyl, ethyl or tert.-butyl group or a phenyl or cyclopropyl group; X represents a hydrogen atom or a halogen atom preferably chlorine or fluorine and n represents 0 or 1.

Examples of particularly preferred compounds of the invention are: 2 - Thienyl methyl ketone N - formyl - 4 fluorophenylhydrazone, 2 - Thienyl methyl ketone N - formyl - 4 chlorophenylhydrazone, 2 - Thienyl methyl ketone N - formyl phenylhydrazone.

The N-formyl-phenylhydrazones of the invention may be prepared by reacting a ketone of formula:

with a phenylhydrazine of formula:

wherein R, R1, X and n have the meanings previously defined in formula (I), followed by reaction with a suitable formylating agent.

This reaction may be carried out using the appropriately substituted hydrazine salt, preferably the hydrochloride, together with an appropriate base, for example sodium acetate.

The reaction is preferably carried out in a polar solvent at temperature ranging from ambient temperature to 1000 C. Suitable solvents are for example ethyl alcohol, diethyl ether or 50% aqueous aectic acid. Alternatively the reaction may be carried out in the absence of a dehydrating agent by using distillation with a liquid carrier to remove water under Dean-Stark conditions. Suitable water immiscible liquids which form an azeotrope with water are for example benzene, toluene or xylene.

The preferred formylating agent is a mixed anhydride of formic acid and acetic acid.

Formylation is usually carried out on the isolated hydrazone compound. However where a liquid carrier has been used to remove water, direct formylation of the liquid carrier solution of hydrazone may be effected.

As mentioned above the N-formyl-phenylhydrazones of this invention possess fungicidal activity and the invention includes therefore within its scope fungicidal compositions comprising a carrier and/or a surface active agent and, as active ingredient, at least one Nformyl-phenylhydrazone of the invention. The invention includes also a method of protecting crops from fungi in which the crops subject. to or subjected to such attack, seeds of such crops or soil in which such crops are growing or are to be grown are treated with a fungicidally effective amount of the composition of the invention or a fungicidally effective amount of at least one N-formyl-phenylhydrazone of the invention.

The composition according to the invention may include a carrier and 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 carrier may be a solid or a fluid. Any of the materials usually applied in formulating pesticides may be used as the carrier.

Suitable solid carriers are natural and synthetic clays and silicates, for example natural silicas such as diatomaceous earths; magnesium silicates, for example, talcs; magnesium aluminium silicates, for example, attapulgites and vermiculites; aluminium silicates, for example, kaolinites, montmorillonites and micas; calcium carbonates; calcium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminium silicates; elements such as carbon and sulphur; natural and synthetic resins such as Coumarone resins, polyvinyl chloride and styrene polymers and copolymers; solid polychlorophenols; bitumen; waxes such as for example, beeswax, paraffin wax, and chlorinated mineral waxes; and solid fertilisers, for example superphosphates.

Examples of suitable fluid carriers are water, alcohols, for example 2-propanol; glycols; ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers; aromatic hydrocarbons, for example benzene, toluene and xylene; petroleum fractions, for example kerosine; light mineral oils; chlorinated hydrocarbons, for example, carbon tetrachloride, perchloroethylene, trichloroethane, including liquefied normally gaseous compounds. Mixtures of different liquids are often suitable.

The surface-active agent may be an emulsifying agent or a dispersing agent or a wetting agent; it may be nonionic or ionic. Any of the surface-active agents usually applied in formulating herbicides, fungicides, or insecticides may be used. Examples of suitable surface-active agents are the sodium or calcium salts of polyacrylic acids and lignin sulphonic acids; the condensation products of fatty acids or aliphatic amines or amides containing at least 12 carbon atoms in the molecule with ethylene oxide and/or propylene oxide; fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohols or alkylphenols for example p-octylphenol or p-octylcresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example, sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as sodium dodecylbenzene sulphonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propvlene oxide.

The compositions of the invention may be formulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols and will generally contain 0.5 to 95% w, preferably 0.5 to 75%w, of one or more Nformyl-phenylhydrazones of formula I. Wettable powders are usually compounded to contain 25, 50 or 75% w of the latter compounds and usually contain, in addition to solid carrier, 310% w of a dispersing agent and, where necessary, 010% w of stabilizer(s) and/or other 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 comppsition usually containing 910% w of one or more N-formyl-phenylhydrazones of formula I. 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 + 25%w of the N-formyl-phenylhydrazones and 010% w of additives such as stabilisers, slow release modifiers and binding agents.

Emulsifiable concentrates usually contain, in addition to the solvent and, when necessary, co-solvent, 10-50% w/v N-formyl-phenylhydrazone, 2-20 w/v emulsifiers and S 20% w/v of appropriate additives such as stabilisers, penetrants and corrosion inhibitors.

Suspension concentrates are compounded so as to obtain a stable, non-sedimenting, flowable product and usually contain 1075% w Nformyl-phenylhydrazone of formula I, 0.5 15%w of dispersing agents, 0.110% of suspending agents such as protective colloids and thixotropic agents, 010% w of additives such as deformers, corrosion inhibitors, stabilisers, penetrants and stickers, and as carrier, water or an organic liquid in which the Nformyl-phenylhydrazone is substantially insoluble; certain organic salts may be dissolved in the carrier to assist in preventing sedimentation or as antifreeze 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 said 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 of the invention may also contain other ingredients, for example, other compounds possessing pesticidal, such as insectidal, herbicidal or acaricidal, properties.

The following Examples further illustrate the invention.

Example 1.

Preparation of 2-thienyl methyl ketone N-formyl-4-fluorophenylhydrazone.

A hot solution of 4-fluorophenylhydrazine hydrochloride (8.1 g, 0.05 mol) in aqueous ethanol (50 ml) containing anhydrous sodium acetate (5.0 g) was added to a solution of 2acetylthiophene (5.5 g, 0.05 mol) in aqueous ethanol (25 ml). The reactants were refluxed for 10 minutes, cooled and excess solvent removed. Diethyl ether and water were added and the ether extracts separated and dried over anhydrous sodium sulphate. After removal of ether the crude hydrazone derivative was recrystallized from 5.0% aqueous alcohol.

2 - Thienyl methyl ketone 4 - fluorophenylhydrazone (4.7 g, 0.02 mol), prepared as above was distilled in a minimum volume of dry 1,2-dimethoxyethane (35 ml), treated with excess of mixed anhydride of formic acid and acetic acid (7.0 ml) and the mixture left for 48 hours at room temperature. Excess solvent was removed at sub-atmospheric pressure and the viscous residue treated with 5% sodium hydrogen carbonate solution and extracted with methylene chloride and filtered over silica gel to remove coloured, polar impurities. The pale yellow crude product was recrystallised from cyclohexane to give the desired product, m.p. 8384 C.

Analysis Calculated for C1H11N2SOF: C 59.5; H 4.2; N 10.7% Found: C 59.7; H 4.4; N 10.6% Example 2.

Preparation of 2-thienyl methyl ketone N-formylphenylhydrazone.

2-Thienyl methyl ketone phenylhydrazone (6.5 g, 0.03 mol) (prepared by the method given in Example 1) was dissolved in dry diethyl ether (37.5 ml) and treated with excess of mixed anhydride of formic and acetic acid (7.0 ml). After 48 hours at room temperature a crystalline product formed and was removed by filtration and washed with a little diethyl ether to give the desired formylated product as pale yellow leaflets, m., 122 124"C.

Analysis Calculated for C1H12N,SO: C 63.9; H 4.9; N 11.5% Found: C 63.5; H 5.0; N 11.2% Example 3.

Preparation of 2-furyl methyl ketone N-formylphenylhydrazone.

2-Furvl- methyl ketone phenylhydrazone (6 g, 0.03 mol) (prepared by the method given in Example 1) was dissolved in diethyl ether and treated with mixed anhydride of formic and acetic acid (7.0 ml). After 48 hours at room temperature excess solvent was removed at sub-atmospheric pressure and the residue recrystallised from cyclohexane to give the desired product as a white solid, m.p.

88-920C.

Analysis Calculated for C1H12N2O2: C 68.4; H 5.3; N 12.3% Found: C 68.8; H 5.3; N 12.6% Example 4.

Preparation of tert.-butyl phenyl ketone tT-formylohenylhydrazone. t-Butyl phenyl ketone (8.1 g, 0.03 mol) and phenylhydrazine (5.4 g, 0.05 mol) mixed in dry xylene (50 ml) were heated under Dean and Stark conditions for 1i hours.

Xylene was removed at sub-atmospheric pressure to give a pale yellow solid, recrystallized from petroleum ether to give the required hydrazone. t-Butyl phenol ketone phenylhydrazone (7.5 g, 0.03 mol) was dissolved in diethyl ether and treated with mixed anhydride of formic and acetic acid (7.0 ml). After 48 hours at room temperature a crystalline product formed and was removed by filtration and washed with diethyl ether to give the desired product as pale yellow crystals, m.p.

71-730C.

Analysis Calculated for Cl8H20N2O: C 77.1; H 7.1; N 10.0% Found: C 76.5; H 7.1; N 9.9% Examples 511.

Following procedures similar to those described in the foregoing examples 1-4 further compounds of the invention were prepared.

The physical characteristics and analyses of these compounds are given in Table I.

TABLE I Example Number Compound m.p. C Analysis 5 2-Thienyl methyl ketone N-formyl- Calculated for C13H11N2SO Cl: C 56.0; H 4.0; N 10.0% 4-chlorophenylhydrazone 87-89 Found: C 56.4; H 4.3; N 9.9% 6 Acetophenone N-formylphenyl- Calculated for C15H14N2O: C 75.6; H 5.9; N 11.8% hydrazone 113-114 Found: C 75.8; H 5.9; N 11.8% 7 Acetophenone N-formyl-4-fluoro- Calculated for C15H13N2OF: C 70.3; H 5.1; N 10.9% phenylhydrazone 69-71 Found: C70.7; H 5.0; N 10.9% 8 Benzophenone N-formylphenyl- Calculated for C20H16N2O C 80.0; H 5.3; N 9.3% hydrazone 99-101 Found: C80.3; H 5.3; N 9.1% 9 4-Chloroacetophenone N-formyl- Calculated for C15H13N2O Cl: C 66.1; H 4.8; N 10.3% phenylhydrazone 59-61 Found: C 66.0; H 4.8; N 10.2% 10 Propiophenone N-formylphenyl- Calculated for C16H16N2O: C 76.2; H 6.4; N 11.1% hydrazone 64-66 Found: C 76.0; H 6.6; N 10.9% 11 4-Fluorobenzophenone N-formyl- Calculated for C15H13N2FO: C 70.3; H 5.1; N 10.9% phenylhydrazone 77-79 Found: C 70.4; H 5.4; N 11.0% Example 12.

Fungicidal activity.

(i) Activity against barley powdery mildew (Erysiphe graminis).

The test measures the direct antisporulant activity of compounds, applied as a foliar spray. For each compound about 40 barley seedlings were grown to the one-leaf stage in a plastic pot of sterile potting compost.

Inoculation was effected by dusting the leaves with conidia of Erysiphe graminis. 24 hours after inoculation the seedlings were sprayed with a solution of the compounds in a mixture of acetone (50%) surfactant (0.4%) and water using a track sprayer. The rate of application was equivalent to 1 kg of active material per hectare. First assessment of disease was made 5 days after treatment, when the overall level of sporulation on treated pots were compared with that on control pots.

(ii) Activity against wheat brown rust (Puccinia recondita).

The test is a direct antisporulent one using a foliar spray. Pots containing about 25 wheat seedlings per pot, at first leaf stage were inoculated by spraying the leaves with an aqueous suspension, containing 105 spores/ml plus a little Triton X-155 ("Triton" is a Registered Trade Mark), 20-24 hours before treatment with the compound under test. the inoculated plants were kept overnight in a high humidity compartment, dried at glass-house ambient temperature and then sprayed at a dosage of 1 kilogram of active material per hectare using a track-sprayer. After treatment the plants were kept at glass-house ambient temperature and assessment made 11 days after treatment. Assessment is based on the relative density of sporulating pustules per plant compared with that on control plants.

(ii) Activity against broad bean rust (Uromyces fabae).

The test is a translaminar antisporulant one using foliar spray. Pots containing 1 plant per pot were inoculated by spraying an aqueous suspension, containing 5 X 104 spores/ml plus a little Tritib X-155, onto the undersurface of each leaf 20-24 hours before treatment with test compound. The inoculated plants were kept overnight in a high humidity compartment, dried at glass-house ambient temperature and then sprayed, on the leaf upper surfaces, at a dosage of 1 kg/ha of active material using a track sprayer. After treatment the plants were kept at glass-house temperature and assessment made 11 days after treatment.

Symptoms were assessed on the relative density of sporulating pustules per plant compared with that on control plants.

The extent of disease control is set out in Table II and expressed as a control rating according to the criteria: 0 = less than 50 /O disease control, 1 = 5080% disease control, 2 = greater than 80% disease control.

TABLE 11 Compound of Formula Fungicidal Activity R R1 X E.g. P.r. U.f.

CH3 CH3 4F 1 2 0 CH3 4--C1 1 2 0 CH3 H 1 2 2 Qs/ CH3 H 2 1 2 CH, 4-F 2 1 2 H ) H 1 0 0 CH3 H 0 0 2 CII3 C, H 1 0 2

Claims

WHAT WE CLAIM IS:- N-formyl-phenylhydrazones of the general formula:

wherein R represents an optionally substituted phenyl, thienyl, furyl or pyridiyl group; R' represents an alkyl, phenyl or cycloalkyl group; X represents a hydrogen or a halogen atom or an alkyl or alkoxy group and n represents 0, 1 or 2.
2. N-formyl-phenylhydrazones according to claim 1, wherein R represents a phenyl, thienyl or furyl group, optionally substituted by an alkyl group or a halogen atom.
3. N-formyl-phenylhydrazones according to claim 2, wherein R represents a phenyl, thienyl or furyl group, optionally substituted by an alkyl group containing 1 to 4 carbon atoms or a chlorine, fluorine or bromine atom.
4. N-formyl-phenylhydrazones according to claim 3, wherein R represents a phenyl, thienyl or furyl group, optionally substituted by a methyl group.
5. N-formyl-phenylhydrazones according to any one of the preceding claims, wherein R represents an alkyl group containing 1 to 4 carbon atoms or a cyclopropyl group.
6. N-formyl-phenylhydrazones according to any one of the preceding claims, wherein X represents a chlorine or fluorine tom.
7. N-formyl-phenylhydrazones according to any one of the preceding claims, wherein n represents 0 or 1.
8. 2-Thienyl methyl ketone N-formyl-4 fluorophenylhydrazone.
9. 2-Thienyl methyl ketone N-formyl-4 chlorophenylhydrazone.
10. 2-Thienyl methyl ketone N-formylphenylhydrazone.
11. Acetophenone N - formylphenylhydrazone.
12. Acetophenone N - formyl - 4 - fluorophenylhydrazone.
13. Benzophenone N - formylphenylhydrazone.
14. 2-Furyl methyl ketone N-formylphenylhydrazone.
15. 4-Chloroacetophenone N-formylphenylhydrazone.
16. N-formyl-phenylhydrazones as claimed in claim 1, substantially as hereinbefore described with reference to Eamples 4, 10 and 11.
17. Process for preparing N-formyl-phenylhydrazones as claimed in claim 1 which comprises reacting a ketone of formula:

with a phenylhydrazine of formula:

wherein R, R', X and n have the meanings defined in clairn 1, followed by reaction with a suitable formylating agent.
18. Proess as claimed in claim 17, in which the formulating agent is a mixed anhydride of formic acid and acetic acid.
19. Process as claimed in claim 17, substantially as hereinbefore described with reference to the Examples 1-11.
20. Fungicidal compositions comprising a carrier and/or a surface active agent and, as active ingredient, at least one N-formylphenylhydrazone as claimed in any one of claims 1 to 16.
21. Fungicidal compositions as claimed in claim 20, substantially as hereinbefore described with reference to Example 12.
22. A method of protecting crops from fungi in which the crops subject to or subjected to such attack, seeds of such crops or soil in which such crops are growing or are to be grown with a fungicidally effective amount of the composition as claimed in claim 20 or 21 or a fungicidally effective amount of at least one compound as claimed in any one of claims 1 to 16.