SE446812B - SET FOR ASTADCOMMA HANDLING STERILITY IN A CEREALIE PLANT WITH CERTAIN 1-ARYL-1,4-DIHYDRO-4-OXOPYRIDAZINES IF USED FOR HYBRID CEREALPHONE PRODUCTION - Google Patents

Description

15 20 25 30 35 40. amino. Alternatively, any two of the groups Z1, 446,812 2 wherein R 1 is a carboxy group (-COOH), or an agronomically acceptable salt thereof, or alkoxycarbonyl -COOR, wherein R is an alkyl group having up to 12 carbon atoms , preferably having up to 4 carbon atoms, R 2 is phenyl or substituted phenyl having up to 3 substituents, which in the case of carbonaceous (a) substituent (s) have a total of from 0 to 6 carbon atoms and which are selected from (1) alkyl, (2) C 4 H 4 = to form a naphthyl group, (3) alkoxy, (4) halogen, (S) nitro, (6) trifluoromethyl, (7) alkanoyloxy and (8) alkylthio, having a total of from 0 to 6 carbon atoms, 7 123 is ccfcp-alkyl and p R4 is hydrogen, (C1-C4) -alkyl or halogen, preferably a bromine or a chlorine atom.

According to a preferred embodiment of the invention, R is a carboxy group or a salt thereof, especially alkali metal salt, while R 3 is a methyl group, R 4 is a hydrogen atom or a halogen atom and R 2 is a substituted phenyl group, especially 4-chlorophenyl. When R 1 is a salt of a carboxy group, an alkali metal, alkaline earth metal or transition metal may form the cation. The cation may also be an ammonium or substituted ammonium group.

Representative examples of metal salt cations include alkali metal cations which are preferred, such as sodium, potassium and lithium; alkaline earth metal cations such as calcium, magnesium, barium and strontium, or heavy metal cations such as zinc, manganese, copper, copper, copper, ferric, ferrous, titanium and aluminum. Among the ammonium salts may be mentioned those wherein the ammonium cation has the formula NZ1Z2Z5Z4, wherein Z1, Z2, Z5 and Z4 (which may be the same or different) represent wheat, hydroxy, (C1-G4) -alkoxy, (C1-C20) -alkyl, (G3 -G8) -alkenyl, (C1-C8) -alkynyl, (G2-G8) -hydroxyalkyl, alkoxyalkyl having from 2 to carbon atoms, (G2-G6) -aminoalkyl, (G2-G6) -haloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted phenylalkyl having up to 4 carbon atoms in the alkyl moiety, amino or alkyl-substituted 22, 25 and Z 4 are joined to form, together with the nitrogen atom, a 5- or 6-membered heterocyclic ring, optionally having up to 4 an additional heteroacid, nitrogen or sulfur atom in the ring and which is preferably saturated, such as in a piperidine, morpholine, pyrrolidine or piperazine ring. Another alternative is that any three of the groups Z1, Z2, Z3 and Z4 may be joined together to form, together with the nitrogen atom, a 5- or 6-membered aromatic heterocyclic ring, such as a pyrrole or pyridine ring.

When the ammonium group contains a substituted alkyl, substituted phenyl or substituted phenylalkyl group, the substituents are usually selected from halogen, (C 1 -C 8) -alkyl, (C 1 -C 4) -alkoxy, hydroxy, nitro, trifluoromethyl, cyano, amino and (C C4) -alkylthio. Such substituted phenyl groups preferably have up to two such substituents.

Representative examples of ammonium cations include ammonium, dimethylammonium, 2-ethylhexylammonium, bis (2-hydroxyethyl) ammonium, tris (2-hydroxyethyl) ammonium, dicyclohexylammonium, t-octylammonium, 2-hydroxyethylammonium, morpholinium, piperidinium, 2-phenethyl methylbenzylammonium, n-hexylammonium, triethylammonium, trimethylammonium, tri (n-butyl) ammonium, methoxyethylammonium, diisopropylammonium, pyridinium, diallylammonium, pyrazolium, propargylammonium, dimethylhydrazinium, hydroxyammonium, hydroxyammonium, hydroxyammonium -nitrobenzylammonium, benzyltrimethylammonium, 2-hydroxyethyl dimethyloctadecylammonium, 2-hydroxyethyl diethyloctylammonium, decyltrimethylammonium, hexyltriethylammonium and 4-methylbenzyltrimethylammonium. Representative examples of R 2 include a phenyl group substituted with (1) alkyl, preferably having up to 4 carbon atoms, (2) C 4 H 4 =, (3) alkoxy, preferably having up to 4 carbon atoms, (4) halogen, such as fluorine, chlorine, bromine and iodine, (5) nitro, (6) trifluoromethyl, (7) alkanoyloxy, preferably having up to 4 carbon atoms, OCh (8) alkylthio, preferably having up to 4 carbon atoms. The most preferred substituents on the phenyl group are 1 or 2 halogenated, a (C 1 -C 4) -alkyl-, preferably methyl- group, a (C 1 -C 4) -alkoxy-, preferably methoxy-, group or a trifluoro methyl group.

Typical compounds within the scope of the invention are, for example: 1-phenyl-1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, 1- (4-chlorophenyl) -1,4-dihydro-4-oxo -6-methylpyridazine-3-carboxylic acid, 1- (4-fluorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, 1- (4-bromophenyl) -1,4-dihydro-4 -oxo-6-methylpyridazine-3-carboxylic acid, 1- (4-Iodophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1- (5-fluorophenyl) -1,4-dihydro -4-oxo-6-methylpyridazine-3-carboxylic acid, 1,1 (3-chlorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1- (3-bromophenyl) -1,4- dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1- (3,4-dichlorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1- (2-fluorophenyl) - 1,4-Dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1-4 (2-chlorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid 1- (4-trifluoromethylphenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, 1- (3-trifluoromethylphenyl) -1,4-dihydro-4-oxo-6- methylpyridazine-3-carboxylic acid, 1-phenyl-1,4-dihydro-4-oxo-6-ethyl pyridazine-5-carboxylic acid, 1- (4-chlorophenyl) -1,4-dihydro-4-oxo-6-ethylpyridazine-5-carboxylic acid, 1- (4-fluorophenyl) -1,4-dihydro-4-oxo- 6-ethylpyridazine-3-carboxylic acid, 1- (3,4-dichlorophenyl) -1,4-dihydro-4-oxo-6-ethylpyridazine-3-carboxylic acid, 1-phenyl-1,4-dihydro + 4-oxo- 6-propylpyridazine-5-carboxylic acid, 1-phenyl-1,4-dihydro-4-oxo-5,6-dimethylpyridazine} carboxylic acid, 1- (4-chlorophenyl) -1,4-dihydro-4-oxo- 5,6-dimethylpyridazine-3-carboxylic acid, 1-phenyl-1,4-dihydro-4-ol-5-ethyl-6-methylpyridazine-3-carboxylic acid, 1-phenyl-1,4, dihydro-4-oxo -5,6-diethylpyridazine-3-carboxylic acid, 1- (4-methylphenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, 1- (2-chloro-4-methylphenyl) -1 , 4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid, 1- (2,6-trichlorophenyl) -1,4-dihydro---oxo-6-methylpyridazine-5-carboxylic acid , 1- (3-ethoxyphenyl) -1,4-dihydro-4-oxo-6-ethylpyridazine-3-carboxylic acid, 1- (4-methylthiophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5 -carboxylic acid, 1- (3-cyanophenyl) -5-bromo-1,4-dihydro-4-oxo-6-ethylpyridazine-3-carboxylic acid, 1-phenyl-5-br om-1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, 1- (5-chlorophenyl) -5-chloro-1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid boxyl acid, 1- (4-chlorophenyl) -5-bromo-1,4-dihydro-4-oxo-6-ethylpyridazine-3-carboxylic acid, and the salts and esters of the above acids.

The compounds used according to the invention can be prepared by means of methods which are per se known for analogous compounds or other methods which can be devised for this purpose.

According to a suitable method, a hydroxy-2-pyrone of formula (II) is reacted, wherein R 6 is a hydrogen atom or an alkyl group and R 3 is as defined above, or a salt of a pyrone of formula II (prepared by treating the pyrone with an equivalent of a suitable aqueous base, such as potassium or sodium hydroxide, acetate or carbonate), usually at a temperature of from -10 to 50 ° C, in a polar solvent, such as water, methanol, ethanol, glyme or dimethylformamide, with a diazonium salt, such as diazonium chloride, prepared by conventional diazotization techniques of an amine of formula 2 (III) R - NH 2 wherein R 2 is as defined above, the product hydrazone, which has the formula (IV) wherein R 2, R 3 and H 6 are as defined above, is then treated with either an aqueous acid such as hydrochloric acid, trifluoroacetic acid, sulfuric acid, methanesulfonic acid or nitric acid, or an aqueous base such as sodium carbonate or sodium hydroxide, preferably at a temperature of from 20 to 150 ° C and preferably from 40 to 10 ° C, to form (by rearrangement) a pyridazine of formula (V) az wherein R 2, R 3 and R 6 are as defined above.

Esters of the pyridazine of formula V are prepared by esterification with a suitable alcohol, preferably a (C1-Cu) alkanol. A conventional technique is a Fischer esterification, in which anhydrous hydrochloric acid or sulfuric acid is used as catalyst and the alcohol as solvent. This esterification is usually carried out at a temperature of from 35 to 150 ° C, optionally using an inert co-solvent such as methylene chloride, ethylene chloride, diethyl ether, toluene or xylene. Salts of the pyridazines of formula V and their 5-halo analogs may be prepared by conventional techniques, such as by neutralization with a suitable inorganic or organic base, in a solvent such as water or methanol.

The compounds used according to the invention, wherein R 4 is a halogen atom, can be prepared by reacting pyridazines of formula V, wherein R 6 is a hydrogen atom, with one equivalent of a halogenating agent, such as bromine, chlorine, sulfuryl bromide or sulfuryl chloride, or the like. in a suitable inert solvent, such as hexane, benzene, ethylene dichloride or methanol, usually at a temperature of from 0 to 50 ° C and preferably at room temperature.

Table I lists typical compounds for use according to the invention as well as their melting points and elemental analyzes. The concrete preparations following Table I show the synthesis of compounds 10, 12, 14 and 16 in Table I, and in these preparations all temperatures refer to ° C, while parts and percentages refer to parts by weight and percentages by weight, respectively, unless otherwise stated. Table I 1-aryl-1,4-dihydro-4-oxo-pyridazines H4 CH; Fïre- n ns -_ nr, H4 X gmg, (° c) 1 H 5-F 215-5 2 H 4-CH3, 202-5 5-01 5 H 4-I 241-2 4 H 4-Br 245 5 H 4 -CF; 254-5 6 H 4-NO2 244-5 7 H 4-cH3 162-5 8 H 2,5- 218-20 -ben- so-4- -01 9 H 4-0cH5 169-70 10 H 4-F 185-7 11 H 5.4- 220-2 0101 12 H 4-01 229-50 15 H 5-01 192-5 14 HH 175 15 Br 4-CH; 241 0 j, Ber.

Found 446 812 002H% 0% H0% N 58.06 5.65 11.29 58.07 5.60 11.55 56.22 5.62 10.09 55.92 5.8 10.90 40.47 2 .55 7.87 41.20 2.46 .05 46.62 2.95 9.06 47.45 5.14 9.26 52.55 5.04 9.40 51.99 2.97 9.15 52 , 57 5.50 15.27 52.76 5.55 15.69 65.92 4.95 11.47 65.66 4.89 11.52 61.06 5.52 8.90 61.07 5.42 8.86 59.94 4.64 10.77 60.14 4.62 10.82 58.06 5.65 11.29 58.75 5.64 11.74 48.18 2.69 9.57 48, 05 2.75 9.21 54.45 5.45 10.59 54.49, 44 10.44 48.51 5.45 8.67 49.57 5.59 9.25 16 15 20 25 446 812 _ Table I ifortsl Förening 4 o nr; R x m.p. (c)% c Sun JN Ha1 16 Br 4-F 219-20 Ber. 5,544.06 2.46 8.57 24.45 * Fumet 44.50 2.52 9.00 24.26 17 Br 4-Br; z5o ° 57.14 2.08 7.22 41.19 a j V _ _ 36.78 1.98 7.35 49.83. 18 Br H ~ '22o ° 46.62 2.95 9.06 25.85 46.68 2.88 9.25 25.62 _19_' c1_ 4-Br 255-9 41.95 2.55 8.16 25.263 ; 7 41.65 2.31 7.74 23.17 x% Br; % F: ber. 5.81; found 5.85 ”ß Br; sheep: asks. 10.57; found 9.91.

Preparation 1 § Compound 10, Table I) Preparation of 1- (4-fluorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carbogyl acid 4-hydroxy-6-methyl-2-pyrone (7 , 88 g) is suspended in 250 ml of water, and 6.65 g of anhydrous sodium carbonate are added to the suspension to effect dissolution of the pyrone.

In a separate flask, mix 7.22 g of 4-fluoroaniline with 25 ml of concentrated hydrochloric acid and 51 ml of water. The solution formed is maintained at about 5-10 ° and a solution of 4.75 g of sodium nitrite in 16 ml of water is added. The resulting solution of 4-fluorophenyldiazonium chloride is added dropwise to the stirred pyrone solution, while maintaining the temperature at about 5 to 10 ° and the pH at about 8 to 9 by adding small amounts of aqueous sodium hydroxide solution.

The hydrazone formed is refluxed for about 2 hours with 500 ml of concentrated hydrochloric acid. Coating and filtration give 10.2 g of 1- (4-fluorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid, which is recrystallized from chloroform / ether (m.p. 185-70).

Preparation 2 (Compound 12, Table I) Preparation of 1- (4-chlorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-carboxylic acid and its sodium salt p-chloroaniline (1.75 g) are dissolved in ml of concentrated hydrochloric acid and cooled to 0 DEG C., and to the solution thus obtained is added a solution of 7.6 g of sodium nitrite at a temperature of between 0 DEG and 5 DEG. The diazotized aniline is added under ice-cooling to a previously prepared solution of 12.6 g of 4-hydroxy-6-methyl-2-pyrone and 55 g of sodium carbonate in 500 ml of water. 10 15 20 25 50 55 40 9 446 812 The slurry formed is heated under reflux overnight. When complete reaction is not observed, the pH is adjusted to 12 and refluxing is continued. The dark solution is neutralized to pH 6-7 with acetic acid and treated with activated charcoal. The filtrate is acidified to pH 2 with concentrated hydrochloric acid under ice-cooling to precipitate the product. The acid is recrystallized from acetone / hexane to give 10.5 g (59%) of 1- (4-chlorophenyl) -1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid (mp 229-250 ° C).

The acid (5.0 g) is converted to the sodium salt by treatment with 0.76 g of sodium hydroxide in 200 ml of anhydrous methanol. The solvent is removed and the solid is washed with ether and dried in vacuo at 90 ° C. Analysis calculated for C 12 H 8 ClN 2 ONa-1/2 H 2 O: C, 48.75; H, 3.07; N, 9.48; Cl, 11.99; Na, 7.78. Found: C, 48.11; H, 2.80; N, 9.24; cl, 12.37; Na, 7.62.

Preparation 5 § Compound Ia, Table I) Preparation of 1-phenyl-1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid In 575 ml of water is suspended 11.8 g of 4-hydroxy-6-methyl- 2-pyrone, and 9.95 g of anhydrous sodium carbonate are added to effect dissolution of the pyrone.

In a separate flask, mix 9.08 g of aniline with 57.5 ml of concentrated hydrochloric acid and 47 ml of water. The resulting solution is maintained at about 5 to 10 °, and a solution of 7.13 g of sodium nitrite in 24 ml of water is added. The resulting solution of phenyldiazonium chloride is added dropwise to the stirred pyrone solution, while maintaining the temperature at about 5 to 10 °. The pH is maintained at about 8 to 9 by the addition of small amounts of sodium hydroxide solution.

After the addition is complete, the hydrazone obtained (18 g) is isolated by filtration and resuspended in 500 ml of concentrated hydrochloric acid.

The mixture is refluxed for 2 1/2 hours and then cooled-1-phenyl-1,4-dihydro-4-oxo-6-methylpyridazine-5-carboxylic acid precipitates as brown crystals which are recrystallized from water. Yield - 7.0 g; m.p.-1750.

Preparation 4 § Compound 16, Table IQ Preparation of 1- (4-fluorophenyl) -5-bromo-1,4-dihydro-4-oxomethyl-pyridazine-3-carboxylic acid 1- (4-fluorophenyl) -1,4-dihydro -4-Oxo-6-methylpyridazine-5-carboxylic acid (1.5 g) is suspended in 100 ml of dry methanol, and 0.242 g of sodium hydroxide is added. To the solution is added dropwise 1.058 g of bromine dissolved in 50 ml of methanol. The solvent is removed leaving a white solid, which is taken up in a dilute base, and the solution is acidified with hydrochloric acid. The precipitate formed is filtered off and recrystallized from chloroform / ether to give 1.4 g of 1- (4-fluorophenyl) -5-bromo-1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid (m.p. 219-20 °).

The compounds of the invention are chemical hybridizing agents in cereals, such as wheat, barley, corn, rice, sorghum, millet, oats and rye. When used as chemical hybridizing agents, the compounds effectively cause a high degree of selective male sterility, i.e. without at the same time causing appreciable female sterility, in the treated plants and without causing appreciable inhibition of the growth of the treated plants.

As the term "male sterility" is used in the present case, it is intended to include both actual male sterility, which is expressed in the absence of male flower parts or in sterile pollen, and functional male sterility, where the male flower parts are incapable of cause pollination. The compounds of the invention also cause other growth regulating effects, such as e.g. control of flowering, control of fruit formation and inhibition of seed formation in non-cereal species and other associated growth-regulating effects.

When the compounds are used as hybridizing agents, they are applied in an amount sufficient to give the desired effect on the plant without causing any undesirable or phytotoxic effect.

The compounds are usually applied to the crop to be treated in an amount of from 0.035 to 22.42 kg per hectare and preferably from 0.14 to 1.1 kg per hectare. The amount applied varies depending on the crop being treated, the compound used are particularly useful as for the treatment and similar factors. To obtain hybrid seeds, the following procedure was usually used. The two "parent" plants to be crossed are planted in alternating rows. The female parent is treated with a compound according to the invention. The thus formed male sterile female parent is pollinated with pollen from the other, male fertile, male parent, and the seeds formed by the female parent will be hybrid seeds, which can then be harvested in a conventional manner. A preferred method of applying a compound of the invention as a chemical hybridizing agent is by foliar application. When this method is used, selective male sterility is effectively achieved when the compound is applied between flowering initiation and meiosis. The compounds of the invention may also be used for seed treatment by immersing the seeds in a liquid preparation containing the active compound or by coating the seeds with the compound. In seed treatment applications, the compounds of the invention are usually applied in an amount of from about 1/4 to 10 kg per hundred kg of seeds. The compounds of the invention are also effective when applied to the soil or to the water surface of rice crops.

The compounds of the invention may be used as hybridizing agents together, e.g. in admixture with other growth regulators, such as auxins, gibberellins, ethylene releasing agents such as ethylene, pyridones, cytokinins, maleic acid hydrazide, succinic acid 2,2-dimethylhydrazide, choline and its salts, (2-chloroethyl) trimethylamide , triiodobenzoic acid, tributyl 2,4-dichlorobenzylphosphonium chloride, polymeric N-vinyl-2-oxazolidinones, tri (dimethylaminoethyl) phosphate and its salts and N-dimethylamino-1,2,3,6-tetrahydrophthalamic acid and its salts. Under certain conditions, the compounds of the invention may be advantageously used in conjunction with agricultural pesticides, such as herbicides, fungicides, insecticides and plant bactericides.

One or more of the compounds of the invention may be applied to the growth medium or to the plants to be treated, either as such or, as is customary, as a component of a growth regulating composition or preparation, which also comprises an agronomically acceptable carrier, such as e.g. a carrier that is agronomically acceptable but pharmaceutically unacceptable. By "agronomically acceptable carrier" is meant any substance which can be used to dissolve, disperse or disperse a compound in the composition without impairing the effectiveness of the compound and which in itself has no appreciable detrimental effect on the soil, the equipment, - the crop or the agronomic environment. The growth regulating compositions can be either solid or liquid preparations or solutions. The associations can e.g. prepared in the form of wettable powders, emulsifiable concentrates, dusts, granules, aerosols or liquid emulsion concentrates. In such preparations, the compound is diluted with a liquid or solid carrier and, if desired, suitable surfactants are incorporated.

In the formulations, the concentration of the active ingredient in each formulation may be from 99.99% by weight to 0.001% by weight. It is generally desirable, especially in foliar application, to incorporate adjuvants, such as wetting agents, dispersants, dispersants, tackifiers, binders and the like, in accordance with agricultural practice. Examples of additives commonly used in this technique are found in the publication "Detergents and Emulifiers Annual" published by John W. McCutcheon Inc. The compounds of the invention may be dissolved in any suitable solvent. Examples of solvents useful in the practice of the present invention are water, alcohols, ketones, aromatic hydrocarbons, halogenated hydrocarbons, dimethylformamide, dioxane and dimethylsulfoxide. Mixtures of these solvents can also be used.

The concentration of the solution may vary from about 2% to about 98% by weight, with the preferred range being from about 20% to about 75%. For the preparation of emulsifiable concentrates, the compound may be dissolved in organic solvents such as benzene, toluene, xylene, methylated naphthalene, corn oil, tall oil, o-dichlorobenzene, isophorone, cyclohexanone or methyl oleate, or in mixtures of these solvents, together with an emulsifier or surfactant which allows dispersion in water. Among suitable emulsifiers, e.g. mention is made of the ethylene oxide derivatives of alkylphenols or long-chain alcohols, mercaptans, carboxylic acids and reactive amines and partially esterified polyhydric alcohols. Solvent soluble sulfates or sulfonates, such as alkaline earth salts or amino salts of alkylbenzene sulfonates and fatty alcohol sodium sulfates, having surfactant properties can be used as emulsifiers either alone or together with an ethylene oxide reaction product. Liquid emulsion concentrates are prepared in the same manner as the emulsifiable concentrates and comprise, in addition to the above components, water and a stabilizing agent, such as a water-soluble cellulose derivative or a water-soluble salt of a polyacrylic acid. The concentration of the active ingredient in emulsifiable concentrates is usually from about 10% to 60% by weight, and in liquid emulsion concentrates it is usually from about 10% to 60% by weight or even as high as 75% by weight.

Wettable powders suitable for spraying can be prepared by mixing the active compound with a finely divided solid, such as clays, inorganic silicates and carbonates and silica, and by incorporating wetting agents, adhesives and / or dispersants into such mixtures. . The concentration of active ingredients in such a wettable powder is usually in the range of from about 20% to 98% by weight, preferably from about 40% to 75%. A dispersant may generally comprise from about 0.5% to about 3% by weight of the wettable powder, and a wetting agent may typically comprise from about 0.1% to about 5% by weight of the composition. .

Dust can be prepared by mixing the active compounds with finely divided, solids, which may be of an organic or inorganic nature. Among materials useful for this purpose, e.g. botanical flours, silicas, silicates, carbonates and clays are mentioned. A suitable method for producing a dust involves diluting a wettable powder with a finely divided carrier. Dust concentrate containing from about 20% to 80% of the active ingredient is usually prepared and then diluted to about 1% by weight to 10% by weight as a concentration in use.

Granular preparations can be prepared by impregnating a solid, such as granular bleaching earth, vermiculite, ground corn cobs, pods, including bran or other pods or similar materials.

A solution of one or more of the compounds in a volatile organic solvent may be sprayed or mixed with the granular solid, whereupon the solvent is removed by evaporation. The granular material may be of any suitable size, with the preferred size range being from 16 to 60 mesh (U.S. Standard Sieve Series). The active compound usually constitutes from about 2 to 15% by weight of the granular preparation.

Salts of the compounds of the invention may be prepared and applied in the form of aqueous solutions. The salts usually make up from about 0.05 to about 50% by weight, preferably from about 0.1 to 10%, of the solution. These compositions may also be further diluted with water, if desired, before actual use.

In certain uses, the activity of these compositions can be improved by incorporating into the compositions an additive such as glycerol, methylethylcellulose, hydroxyethylcellulose, polyoxyethylene sorbitan monooleate, polypropylene glycol, polyacrylic acid, polyethylene sodium maleate or polyethylene oxide. The additive usually constitutes from about 0.1 to about 5% by weight, preferably from about 0.5 to about 2%, of the composition. Such compositions may also optionally contain an agronomically acceptable surfactant.

The compounds of the invention can be applied in the form of sprays by conventionally used methods, such as conventional hydraulic spray, air spray and dust. For low volume applications, a solution of the compound was usually used. The dilution and application volume usually depend on such factors as the type of equipment used, the method of application, the area to be treated and the type and stage of development of the crop being treated. § 15 40 35 44 14 446 812 The following examples illustrate the growth regulating activity of the compounds used according to the invention but are not intended to limit the invention in any way.

Example 1 Chemical Hybridization Activity The following procedures were used to evaluate the activity of the compounds of the invention in achieving male sterility in cereals. A bait brush variety (Fielder) and a bait brush free variety (Mayo-64) of spring wheat are planted in an amount of 6 to 8 seeds per 15.25 cm pot containing a sterile medium of 3 parts by weight of soil and one part by weight. humus. The plants are allowed to grow under short-day conditions (9 hours) during the first 4 weeks in order for them to achieve good vegetative growth before flowering begins. The plants are then transferred to long-term conditions (16 hours), which conditions are achieved by means of high-intensity lamps in greenhouses.

The plants are fertilized 2, 4 and 8 weeks after planting with a water-soluble fertilizer (nitrogen-phosphorus-potassium = 16% -25% -16%) in an amount of 1.3 ml per liter of water and are often sprayed with a suitable insecticide. , such as that marketed under the trademark "Isotox", for the control of aphids and treated with sulfur dust to prevent the formation of mold.

The test compounds are applied to the leaves of the female plants provided with bait bristles, when these plants reach the stage of development with sharp leaves (step 8 on the Feeke scale). All compounds are applied in a carrier volume of 468 l / ha containing a surfactant, such as that marketed under the trademark "Triton X-100", in an amount of 0.3 g / l.

After the ear has developed but before antesis, 4 to 6 ears per pot are placed in bags to prevent crossing. At the first signs of flower opening, two ears per pot are cross-pollinated, using the experimental method, with the male plant free from bait bristles. As soon as the seeds become clearly visible, the axle length is measured and the number of seeds per axle is counted for both the axle in bags and the crossed axes. Male sterility can then be calculated as the percentage inhibition of seeds obtained in the bagged axes of the treated plants, and the female fertility of the crossed axes can be calculated as a percentage of control or comparison seeds. After ripening, seeds are planted on crossed ears to determine percentage hybridization. The "experimental method" mentioned above involves bringing the ears to be cross-pollinated close to each other or in contact with each other. 444 812 The percentage sterility, the percentage fertility and the percentage inhibition of the shoulder length are calculated using the following formulas: S _ S a) z steriutec = ° S tx 1oo c 'SC = seeds / small ears 1 axis of control plants placed in bags St = seeds / small ears in ears of treated plants placed in bags b) æ ferßiiltet = Ft x 1oo C.

Ft = seeds / small ears in experimentally crossed ears of treated plants Fc = seeds / small ears in ears of control plants not placed 1 bags ^ c) 5% axial inhibition = He 'H1: x 1oo c Hc = shoulder length of control plants Ht = shoulder length of treated plants.

Table II summarizes typical results obtained in evaluating compounds of the invention. A line indicates that no determination of the value was made. 16 446 812 TABLE 11 éametocidal activity x> 76 sterility (at low / ha) x gi, 3 8.96 4.46 2.24 1.12 0.56 0.26 of H .H '-__ 100 94 12 46+ - 1+ 144. 63 of H Na __- 100 100 100 100 a1 4_cH3,3_c1 HH 16 9 10 9 14 10 _-- 4-cH3, a-c1 H Ha 0 14 2 13 6 __- 4-1 HH __- '100 100 100 99 --- _ 4 -IH na 100 100 100 100 100 97+ 92 4-Hr HH __- 100 100 100 100 _-- 4_ar H Na 100 100 100 100 10o + 98; 86 73 4-cH3 _ _ HH _-- 100 97 100 96 _-- 4_cH3 H Ha 100 100 .100 100 97+ 99+ ~ 90 so 4_Ho2 HH 9 18 -__ __- __- --- 4_N02 H Ha 9 16 a 16 e --4 4_cH3 HH 73 41 ___ ___ __- --- 4-cH3 H Ha 100 96+ 92+ 'sa 12 ---' 100 '100 10 15 20 25 30 35 X 4-91. (naphthyl 4 -C1 Inaphthyl) 4-OCH3 4-OCH3 4-F 4-F 3,4_01c1 I3,4_a1c1 4-Cl 4-C1 3-C1 3 ~ C1 HH 4-CH 4-CH 4-F 4-F 4-Br 4-Br II III I 'Br Br Br Br Br Br Br Br.

_C1 Br Na Na * Na Na na na na na na na na na na CH 3 17,446,812 0 TABLE II ts 0r111: 0 d k now 0.9. 0. . . 0.20 33 15 -__ __- __- -__ 0 ~ s 4 4 9 -__ - 100 94 ___ ___ ___ -__ - 100 100 * 99 * 03 * 43 * __- 100 90 100 100 100 _-_ __- __ - -__ -__ 100 100 100 100 - 95 _66 * 00 100 ___ _-_ -__ __- -_- 100 90 92 16 __- -__ _100 100 96 __- --_ --- 100 100 100 * 100 * 100 * 100 * 45 34 90 72 06 -__ -__ __- __- _-- 10o 100 74 64 * 94 -_- 0 73 vs ___ ___ _-_ ___ __- 1001 100 100 100 97 * 40 * 90 97 -__ 0 29 10 v -__ 9 3 ___ 0 7 -__ 1o0 100 100 100 * 04 * 15 es 13 -__ __- ___ 02 40 32- --- -__ ___ 100 00 10 ~ - __- '100 100 92 pp --- ++ --- ++ --- 100 -Q- "'100 __- 100 _-- 100 ___ ~ - ~ - C? H5 10 15 20 25 18 446. 812 + results of several performed results x 35 at 0.11: kg / na xx 0 at 0.14 kg / ha me: 96 at 0.14 kg / na xxxx 99 at 0.14 kg / ha ++ development of ax inhibited at 2.24 and 8.96 kg / ha Among the compounds used according to the invention, a new class of compounds can be distinguished, namely compounds of the previously stated formula I in which R has a meaning other than hydrogen, eg halogen. special use feasibility in providing a way to improve by hybridization the commercial value of seeds for production cereals (1), which means that in a mechanical spreading device a hybridization composition containing a compound of formula I and an agronomic acceptable carrier for this, (2) using the mechanical spreading device to apply in the form of a dust or a liquid spray the hybridization composition to the leaves of a male and female cereal plant before meiosis, thereby achieving male sterility, (5) by pollinates the "parent" plant thus treated with pollen from a male plant of the cereal, (4) by allowing the pollinated plant to mature until seeds are formed and (5) by harvesting the ripened seeds.

Furthermore, Table III shows further prepared compounds within the scope of the invention, while Table IV shows physical data and / or elemental analyzes for the compounds in Table III, and Table V shows data on male sterility for the compounds in Table III, which data have been obtained according to the procedure. written in connection with Table II. u ... ....._..-.-__-. ~ _.___.__.-. Table H 1 446 812 Table III 1-aryl-1,4-dihydro-4-oxo (thio) -pyridazines x Example R4 R3 x R 'AH cH3 H 4-Br coz-n-c4H9 BH cH3 4-1 co2cH3 c H CH3 4-1 coz-Q-c4H9 DH CH3 4-cl CO2- (1 / zcu ++) EH cH3 4-cH3s cozcns FH CH3 4-cH3co2 co2Na GH CH3 4-cH3s co2Na H Q-c3H7 CH3 4-c1 co2cH3 1 H g-c4H9 4-c1 cozcH3 JH cH3 4-c1 co2cH3 KH cH3 4-c1 coz-H-c6H13 LH cH3 4-c1 ocH2c6H13 MH CH3 4-c1 ocH3 NH cH3 4-C1 ocH3 0 H CH3 4-c1 oc2 PH c2H5 4-c1 ocH3 QH CZHS 4-c1 oNa R CH c H _4-c1 oNa 3 2 5 310 15 20 25 30 35 20 446 812 Table IV Example m.p. (° c) 80 88 1N 8961 A 85.5-88 calcd. 52.61 4.69 7.67 found 52.25 4.70 7.90 B 186-189 42.18 3.00 7.57 41.95 2.91 7.16 c 134-137 46.61 4, 16 6.80 46.84 4.26 6.95 n 263-265 41.24 4.04 8.02 10.15 °) 39.55_ 3.40 7.62 9.35 E 157-159 57.91 4.86 9.650 _ 57.98 4.88 9.66 F 300 51.22 3.99 8.54d) 51.32 3.73 8.68 0 310 --- --- --- H _ha1vf6st 59, 90 5.34 8.74 60.13 5.45 8.57 1 6136 59.90 5.34 8.74 59.85 5.61 9.11 J 183-193 49.54 3.84 8.89f) 50.12 3.69 9.29 K 62.33 5.52 8.08 62.45 5.72 8.45: L -125-127 63.24 5.87 7.77 63.44 5.97 7 , 48 M 154-156 52.97 3.76 9.515) 52.45 3.89 9.48 * N 200-202 56.02 3.98 10.05 12.72 56.15 4.06 10.10 12 .71 0 143 57.44 4.48 9.57 12.11k), 57.37 4.51 9.56 12.06 P 110-114 57.44 4.48 9.57 57.20 4.34 9 , 60 Q 48.99 3.80 8.79m) 48.22 3.56 9.22 R 165 50.53 4.24 8.42 “) 50.39 3.86 8.41 10 15 20 25 30 35 found 15.96 21 446 812 Table IV kept. c) 8 Cl; 8 Cu: ber. 9.09; found 10.60; $ 1 & 02 ber. d)% Na: ber. 7.01; found 8.19 f) analysis for hydrochloride salt j) 8 S: ber. 10.88; found 12.25 k)% Cl: m)% Na: ber. 7.22; found 7.40;% H 2 O calcd. 5.65; found 4.74 (monohydrate) n)% Na: ber. 6.91; found 6.1; % H 2 O: calc. 5.42; found 4.31 (monohydrate) Example _9_ A _-- B _-- C ___ D _-- E 100 F _-- G _-- H -__ I _-- J ++ K _..- L _ - M 100 N ___ 0 100 p _-- Q 100 R 100 15.47; 9.214 1 Table V 1 male sterility (at kg / ha) Lä 1.1.1 Lä hå --- --- 100 100 --- --- 100 '100 --- --- 100 100 100 +++ 100+ ++ 91 +++ 63 +++ 96 --- 56 --- 3 --- 0 --- --- 19 8 7 --- 100 100 100 --- 49 7 0 ++ --- 100 --- --- 31 12 2 --- 63 9 1 99 --- 67 --- --- 100 100 100 100 ---- 100 --- --- 100 100 100 100 100 100 100 98 100 88 37 2 and 9 kg / ha ++ development of ax inhibited in 2.3 +++ soil soaking test, not leaf spray 90 98 00 16 5 89 0 96 98 99 98 95 0.07 90 97

Claims (4)

446 812 g 22 PATENT CLAIMS 1. Methods of achieving male sterility in a cereal plant, characterized in that the plant is treated before meiosis with an amount which is effective in causing male sterility in the plant, of at least one compound of the formula Ru 'w' H5 lf / N R2 'wherein R1 is carboxy, or an agronomically acceptable salt thereof, or alkoxycarbonyl having up to 12 carbon atoms in the alkoxy moiety, R2 is phenyl or substituted phenyl having up to 3 substituents, which in the case of carbonaceous (a) substituent (s) have a total of from 0 to 6 carbon atoms and which are selected from (1) alkyl, (2) C 4 H 4 = to form a naphthyl group, (3) alkoxy, (4) halogen, (5) nitro, (6) trifluoromethyl, (7) alkanoyloxy and (8) alkylthio, R 3 is (C 1 -C 4) alkyl and g R 4 is hydrogen, (C 1-6 C 4) -alkyl or halogen. A method according to claim 1 when used for the production of hybrid cereal seeds, characterized in that a male / female plant of the cereal is treated with said compound of formula I, causes the plant thus treated to be pollinated with pollen from a male plant of the cereal, it allows pollinated plant mature until seed formation is essentially complete and harvests the mature seeds. 3. A method according to claim 1 or 2, characterized in that R 1 is carboxy or an alkali metal salt thereof, R 2 is 4. -chlorophenyl, R 5 is methyl and R 4 is hydrogen.