BE653800A - - Google Patents

Description

       

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  Pongicides
The present invention relates to the use of 2-isoxazolin-5-ones as fungicides, novel 2-isoxazolin-5-ones, and methods for their preparation. The subject of the invention is fungicidal compositions containing as active constituent a 2-isoxazolin-5-one of formula:
 EMI1.1
 where R represents a carboxymethyl or carboxyethyl radical or an alkyl radical of 1 to 6 carbon atoms, optionally bearing

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 as a substituent a hydroxy or cyano group or a halogen atom and R1 is a substituted or unsubstituted phenyl or naphthyl group, and a vehicle for the active component, which may be an inert solid diluent or a liquid diluent containing a surfactant .



   When the radical R1 is a phenyl or substituted naphthyl radical, the substituents may be, for example, one or more
 EMI2.1
 sieurs members of the class formed by raef.a 5iKyle and .l alkoxy from 1 to 12 and in particular from 1 e: é6 carbon, the radicals ç, c7oalkyl, aryl (or aryl substituted), arylazo (or 'arylazo substituted ), aryloxy, halogen atoms, carboxy, alkoxycarbonyl, carboamino, cyano, nitro, hydroxyl, trifluoromethyl, m1no, N-alkylamino, N, N-dialkylamino, acid sulron1 ques sta.ionanKn, aminosulfonyl or thiocyanate .



   It has been found that the compounds in which the radical R1 is a chloro-substituted phenyl radical or a phenyl radical substituted by a lower alkyl radical have interesting fungicidal properties, as emerges from the examples below.
 EMI2.2
 Examples of disubstituted phenyl radicals killed are those in which the substituents are two alkyl radicals or two alkoxy radicals, any two halogen atoms, one alkyl radical and one alkoxy radical, one alkyl radical and one nitro radical. , an alkoxy radical and a nitro radical, an alkyl radical and an atom
 EMI2.3
 d> halogen or an alkoxy radical and a halogen atom.



   The compound used as an active component can, if desired, be in the form of one of its salts, for example its sodium or potassium salt.
 EMI2.4
 Some of the compounds of the invention have been found to be very effective as foliage fungicides, others as seed coating fungicides and some as soil fungicides; the particular presentation of the fungicidal composition depends on
 EMI2.5
 a large extent of the intended use of the composition and .. 1 i. the pathogen to be controlled. For example, the compositions can. be powders, solutions, dispersions or pastes.

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  When in the form of powders, they can comprise the active component and a powdered diluent. In liquid form, the composition may comprise the active constituent in solution or in suspension in a suitable liquid, pure example of water or a suitable non-phytotoxic organic liquid), The constituents used with the active constituent in one or more the other of the fungicidal compositions of the invention may be substances known for the preparation of fungicidal compositions, for example surface-active substances, such as wetting and dispersing agents, binders, adhesives, corrosion inhibitors and stabilizers.



   The fungicidal compositions of the invention which have proved useful as liquids for coating the segments are solutions of the sodium salt of 3-methyl-4-phenylhydrazono-2-isoxazolin-5-one in ss-. ethoxyethanol, diacetone alcohol or ethylene glycol, and in particular solutions in which the sodium salt is present in an amount of approximately 25% weight / volume.



   A subject of the invention is also the new 2-iso-xazoline-5-ones of general formula:
 EMI3.1
 where R is an alkyl radical of 2 to 6, and in particular of 2 to 4 carbon atoms, a carboxyalkyl or alkoxycarbonylalkyl radical having not more than 4 carbon atoms, and R1 is a phenyl radical or @ substituted or not ; or where R is an alkyl radical
1 to 6 and in particular from 1 to 4 carbon atoms or a carboxyalkyl or alkoxycarbonylalkyl radical not having more than 4 carbon atoms, and R1 is a chloro-substituted phenyl radical and their salts.



   Suitable 2-soxazoline-5-ones as constituents

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 active agents for the fungicidal compositions of the invention can be obtained, for example, by a process in which a ketoester of formula is reacted:
R - CO - CH2 - COOR3 where R is an alkyl radical of 1 to 6 and in particular of 1 to 4 carbon atoms or a carboxyalkyl or alkoxycarbonyl-alkyl radical having not more than 4 carbon atoms and R is an alkyl radical of 1 to 4 carbon atoms, with the appropriate optionally substituted phenyl- or naphthyldiazonium salt and hydroxylamine or a hydroxylamine salt.

   The process is advantageously carried out by dissolving or dispersing the reactants in water or in a mixture of water and ethanol. The diazonium salt can advantageously be formed in situ by the reaction of the appropriate amine. required and nitrous acid, as shown in the examples below.



   A second process for preparing 2-isoxazolin-5- 'ones consists in reacting an azo compound of the formula:
 EMI4.1
 where R and R3 have the meanings given to them in the above description of the first process and R1 is a phenyl or naphthyl radical substituted or not, with hydroxylamine or a salt of hydroxylamine. This process is advantageously carried out under moderately alkaline conditions, for example by dispersing or dissolving the reactants in water or in a mixture of water and ethanol in the presence of a caustic alkali or sodium acetate, or well in pyridine.

   Since the reaction is generally slow at room temperature, the process is preferably carried out at an elevated temperature, for example 60 to 115 ° C. The azo compound used in the second process can be advantageously obtained in situ by reaction of a ketoester of formula:
 EMI4.2
 R - CO - CH2 - COOR3

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 with the appropriate diazonium salt.



   For the preparation of the compounds of the invention in which the group R is a methyl group, results are obtained.
 EMI5.1
 satisfactory using dicetene instead of a ketoentert
A further subject of the invention is a process for combating pathogenic organisms in plants whereby the leaves of a plant susceptible to these pathogenic agents, the seed from which the plant originates or the soil from which the plant is brought to. to grow is treated with a fungicidal compound or composition as described above,
The invention is illustrated by the following examples.
 EMI5.2
 



  'it #'.! - Ethyl acetoacetate (6.6 g), hydroxylamine hydrochloride (3.5 gases of "m.-to7.u.dine (5.1g) and l Concentrated aqueous hydrochloric acid (10 cc) is mixed with water (25 cc and the mixture is cooled to about 5 cc A cold solution of sodium nitrite (4.0 g) in water (10 cc is added
 EMI5.3
 slowly to the mixture, with stirring, taking care that the temperature does not rise above 10 C. The balance is then suspended for 6 hours, allowing the temperature to rise slowly to
 EMI5.4
 about 20 C, then filter.

   The solid residue isolated on the filtered Fe is washed with water and recrystallized from a mixture of ethanol and benzene. The product obtained in the form of yellow crystals is 3-methyl-4.
 EMI5.5
 Ç39-meth-vlo'hp'nvlhvdi, c, zono) -2-isox-zolinp-5-onp, melting at 172 C.



  EXAMPLE 2.-. Suspended in water (60 cm3 of 3-chloro-
 EMI5.6
 4-methylanlline (7.1 g) and the mixture is acidified with concentrated hydrochloric acid (18 cm3). After cooling to 5 c the -mixture is diazotized with a solution of sodium nitrite 4.0 g) in water (15 cm3 The solution obtained is then added!
 EMI5.7
 slowly with stirring in a cold mixture (5 C) of ethyl acetate (6.6 g) in ethanol (170 cm3 and water (45 cm3) to which anhydrous sodium acetate has been added ( 24 g). The mixture is

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 left at about 20 ° C for 15 hours then filtered and the solid residue isolated on the filter was washed with water.

   The residue is dissolved
 EMI6.1
 in boiling ethnnol (100 cm3) and the solution is slowly added to a hot solution of hydroxylamine hydrochloride (3.5 g) in water (100 cm3 to which anhydrous sodium acetate (8, 2 g) was added The resulting mixture was heated under reflux for 15 minutes, left for 15 hours at approx. 20 liters.



  The solid residue isolated on the filter is washed with water and recrystallized from ethnnol. The product obtained in the form of yellow crystals
 EMI6.2
 is - <thvl -! - '-chloro .. -, th 1 hn i d azono -2-iso roline- 5-one melting at 192 C.
 EMI6.3
 ., .. ¯, 3: 3-
A number of other 2-isoxazolin-5-ones are prepared by the general methods described in Examples 1 and 2, but using the appropriate amine in each case instead of
 EMI6.4
 m.toluidine and 3-chloro-4-methylaniline used in these examples, respectively. These other 2-isoxazolin-5-ones are listed under the heading "Examples" in the table below. The products of Examples 3 to 15 are obtained by the process of the Example.



  1, while those of Examples 16 to 33 are obtained by the process of Example 2. The products of Examples 3 to 33 are believed to all have the general formula
 EMI6.5
 
 EMI6.6
 , where R is a benzenlque'subst1tUf ring. and the products are identiwf '. riôs dfS each example by the meaning given to R in the? ; column with this heading. For convenience, double bonds have been omitted in all benzene rings.



  The melting point indicated for each product is that obtained using a sample of the product purified by recrystallization.

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  TABLE1
 EMI7.1
 Example Product Ri PF (OC) Aspect binds 193 Young crystals O 014e 208 Crystals \ ## / 'oranges 1, le 5 150 Cristrux J. <Ornncës 6 ci 192 Crystals -0 young c - 168 Crist;, ux \ x orange- s 142 Crystals \ "Ile oranges FtC z 9 - <(\ 140 Crystals \ # / - oranges 0Et 150 Crystals ## / ormng6s 214 Crystals ## <jrunGS, 'e 12 .. i'le 199 Cristrux ¯¯¯ 1¯ .¯. / ¯-¯ .¯¯¯..¯..¯ .----. Jf unc

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 TABLE 1 (Continued)
 EMI8.1
 Example - ######### '###.

   Product no Ri PF (C) Appearance 1-le tie 13 \ ¯¯ / v3 Orange crystals 14, ;; 1¯ 205 Crystals ## / brown - <.- e '128 Crystals' 128 Crystals.)' Barns :: c 16 C1 148 Crystals '.' 'The oranges 17 .. 171 Crystals: 2nd orange ci 18 Cl 193 Crystals yellow "' Br 9 163 Crystals Â3 brown brown Ke Cl 1 20 \ 194 Crystals ## yellow 21 148 Crystals. Yellow s ci CI 1 22 - / '\ 170 Crystals S, ¯¯ / yellow

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 TABLE I (Continued)
 EMI9.1
 Example ¯¯¯¯¯¯¯¯¯¯¯ Product¯¯¯¯¯¯¯¯¯¯¯ n R P.F, (00) Appearance 23 C1 182 T Crystals Yellow Cl Fasting ..



  . 'fe .. 2Jt' 168 'C1 yellow crystals Br 25 - \ z.5 Crystals ## young 26 -0-, 16S Orange crystals omneéB .27 r- <.. 200 Yellow crystals' Cl, 28 - (\ -C1 160 Yellow crystals j, p 29 -0 Ii '' "182 Cr1ntRUX! ^ - = rouses ..



  30 'ci # 3 198 Crystals * ## r:) or.t: ornn8s f .-) OT: t' orang8s 3i .. 96 Crystals' * # jnunes 1 :. U '"32 ¯ /' \ 120 Crystals y Yellow 33 r P1 = PI-- 208 Crystals' ## \ # rou & o brlue

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 EMI10.1
 ± J @ "1, ± y ± -
 EMI10.2
 Tyla lynketoacetate (6 $ 6 g), 3ne hydroxyl hydrochloride (3.5 C), α-chloronnlline (6, c) and concentrated aqueous hydrochloric acid (10 ca3) are added to ethnnol (10 cm3) and the is cooled. at. about 5''C. A solution of cold sodium nitrite (4.0 C) in water (10 cm3) is slowly added to the mixture with stirring so that the mixture does not. 10 c. The handle is then agitated in the direction of the windshield 3: art-s, the temp4r-turn rises slowly for a period of time to about 200 and then filter.

   The solid residue collected on the filter is lnv4 with water and recrystallized in a mixture of ethanol and 'benzene. The product obtained in the form of brown crystals is' -thz1-, '' wahlornahn lh 3rzono-2-isoxnzol ne- -oe melting at 162 C ..



  EXAMPLE 35
 EMI10.3
 -6ethylanlne (6.1 s) is suspended in water (60 cm3 and the mixture is acidified with concentrated aqueous hydrochloric acid (18 cm3 After cooling to 5 c the mixture is diazotized to using a solution of sodium nitrite (4.0 g in water (15 cm3).

   The solution obtained is added slowly with stirring to a cold mixture (5 C) of ethyl acetoacetate, (6.6 g) of ethanol (170 cm3) and water 45 cm3) to which has been added anhydrous sodium acetate (24 g The mixture is left at about 20 C for 15 hours and the thick oil obtained is separated from the aqueous layer and washed with water. The washed oil is dissolved in the water. boiling ethanol (100 cm3 and this solution is added
 EMI10.4
 slowly to a hot solution of hydroxylanLne hydrochloride 3.5 g in water (100 cm3) containing anhydrous sodium acetate 3.2 g). The resulting mixture is heated at reflux temperature for 15 minutes, left for 15 hours at about 20 ° C. and filtered.

   The solid residue isolated on the filter is washed with water and recrystallized from ethanol. The product obtained in the form of a cris-
 EMI10.5
 tvix yellow is -mêthvl -.- (l'-éthwrlhény, lhydrzono) -2-isoxazol-,

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   ne-5-one, melting point 154 c EXAMPLE 36
The process of Example 35 is repeated, but
 EMI11.1
 çanting 2-ôthylaniline (6.1 g) with 2-ethYlanllin (6.1 g). The product recrystallized from ethanol in the form of orange crystals is -mCth 1- - 2'-eth 1 rn th d a ano ..2-isoxayo e ..



  5-one..melting point 122 C.



   Examples 37,38 and 39 describe the preparation of various salts of 2-isoxazolin-5-ones.



  EXAMPLE 37
 EMI11.2
 J-methyl-4- (3'-nethylphenylhydrazino) -2-isoXazoli- de-5-one (3 g of the product obtained in Example 1) is suspended in a 10% aqueous solution of hydroxide. sodium (30 cm3) and ethanol (30 cc is added. The mixture is heated at about 80 ° C. for 2 minutes and the solution obtained is filtered.



  On cooling the filtrate, a crystalline solid precipitates and is separated by filtration and then washed with ether. The product obtained is
 EMI11.3
 the sesciuihydrite of the sodium salt dcla '3-rdthvl - / .- (3 t-methyl r) htn.Y-. hydrazono) -2-isoxazolin-5-one occurring as Yellow leaves which slowly decompose on heating but are incompletely melted at 300 C.



    EXAMPLE 38.-
The process of Example 37 is repeated, replacing the
 EMI11.4
 3-metr.y -, .- (3'-methylphenylhydra zono) -2-isoxazol3ne-5-one (3 g) by 3-methyZ-h- (t'-chlorophrnylhydrazono) -2-isoxazoline-5. one (3 g of the compound obtained in Example 6). The product is present in the form of young crystals is trlhynrnt.nu sp1 our. J1: l <..) il ',. - -chl.oro hF n 1h razono -2-isoxzoine- -one, -iaant at 1 0 C with decomposition.



    EXAMPLE 39.-
The process of Example 37 is repeated, but 3-methyl-
 EMI11.5
 .- (3'-Methylphér.ylydrazono) -2-isoxazolin-5-one (3 g) is replaced by 3-mthyl -! - (t'-chlorophÉnylhydrazana) -2-3soxr.zol3ne- 5-one (3 g of the product obtained in Example 6) and the solution

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 aqueous sodium hydroxide at the $ (30 cm3) is replaced by a 10% aqueous solution of potassium hydroxide (30 cm3).



  The product in the form of yellow crystals is
 EMI12.1
 sesciuihydrate of sodium salt of -meth 1- - '-chloro hén 1-.' hyd ra zono) - 2- i soxs zol ine-5-one decomposing at 170-1800C. EXAMPLE 40
This example describes the preparation of 3-methyl-4-
 EMI12.2
 (2: l ': 5'-tricP.7.orophé'nylhydrazono) -2-isoxazolin-5-one by a method which is a variation of the general method described in Example, 2. The modification consists essentially of using pyridin instead of ethanol in the third stage of the process, in which the reaction product of the diazonium salt and the ketoester is reacted with hydroxylamine hydrochloride.



   The wet crude intermediate (23 g) obtained by reacting ethyl acetoacetate (6.5 g) with the chloride
 EMI12.3
 of 2: 1: 5-trichlorophenyl-diazonium by the general method of Example 2 is mixed with 3.5 g hydroxylamine hydrochloride and pyridine (75 cm3 and the mixture is heated to reflux temperature for 1 hour. the product obtained is then poured into ice-water containing hydrochloric acid and the precipitated solid is separated by filtration and recrystallized.
 EMI12.4
 in ethanol giving the -mf tlml-l (2 ': /:

   5'-trich7.orohnv1- hvcirazno) -2 - i oxazolin P-5-one in the form of a reddish brown solid, melting at 151 c EXAMPLES 41 to 78
A number of other 2-isoxazolin-5-ones are prepared by the general method of Examples 1, 2 or 40 above,
 EMI12.5
 '. using various cE.toasters., and the appropriate amine in each case. These 2-isoxazolin-5-ones are shown in Table 2 below under the heading Examples
The products of Examples 41 to 78 are obtained by processes using a ketoester of formula: R-CO CH2 COOEt and a diazonium chloride of formula-:

   Cl-N = N-R1 and they. ' are, .

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 we believe, a structure corresponding to the general formula i
 EMI13.1
 where R is an alkyl or alkoxycarbonylalkyl radical and R1 is a substituted benzene ring.



   In Table II below, the product of each example is identified by the nature of the R and R1 groups and for convenience the double bonds have been omitted in all benzene rings.



   Jump in Examples 52, 67, 68,72,73,75 and 76, the compounds of Table II are obtained using the general process of Example 2 above, but each time using the ketoester and the amine appropriate. As regards the exceptions, the compounds of Examples 67 and 68 are obtained by the general procedure of Example 1 above; and the compounds of Examples 52, 72, 73, 75 and 76 by the general method of Example 40 each time using the appropriate ketoester and amine.



   TABLE II.
 EMI13.2
 



  Example Product 0 R RI P.F. (C) 41 CH .. 48! Le ItH9 42 -Q-D.C 4H9 92 43, D-nC12H2S 91 44 - (- 202 45 -Qoc2H5 162 OC2H5

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 TABLE II - (continued)
 EMI14.1
 Example ¯ Product 1 P. F. (oc) 3 -ccooc 2H5 4 47 "oH 11? 48 fi ± D N (CX3) z 170 49" ± D SO2Ifi2,., 22b ..



  50 70 Br '194 51 199, 51 1' ± 199 5: 4 - (x -.... i CN 17 .4, ,, I "</ CJ! P 53") ## \. '; 'lil 4 oc2il 0p "c -' i51 oc 2 H OC-fil '25 - -. =>.



  55 176> 1. / U, ¯ ,, iI 176 or 3117 56 .. - / - <'oc 3 H7

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 TABLE II (Continued)
 EMI15.1
 Example ¯¯¯¯¯¯¯¯¯¯¯¯¯ Product, nO R P.. (G 57 CH3 OCH 3 oc: :) 58 "'- \ 146 C'3 ncx 59 151. 3 ..



  . CH1 CH.3 '60 na = rrW, 127 61 Yl102 190 c'3 llo 190 62 "--CH 177 NO 2 1' 2 63" '± j 175 CH-:,) fl oH3, 199 .1 '10 6 5 "-0CI02 208 OC"

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 TABLEII (Continued)
 EMI16.1
 Example Product no Ri P * F. (C) 66, CH: D- CH3 '-184 bzz3 1102 bzz3 ...



  67 C2H; 118 134 CH3 69 -Q 135 r 70 - / '' ''? 'CC2H5' 145 '-Q Cl 160 C'. C1 ..



  72 150 73 n.C4H9 -. \ 83 74 C2HS-OQC-ÇH2 126 CH., 1 '.1 115! CIi 76 113 ÇH

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 TABLE II (Continued)
 EMI17.1
 Example Product no R R1 PF (oc) 77 C2H5-ooc-cH2 -coc2H 5 127 78 -Q ci 220 'EXAMPLES 79 to 88 Table III below shows under the heading of examples a certain number of other 2-isoxazolins -5-ones used in fungicidal compositions. The different compounds are identified in Table III, as in Tables 1 and 11 by the nature of the R and R1 groups. For convenience the double bonds have been omitted in all structures shown.



   TABLE III.
 EMI17.2
 



  Example No. Ri P.F. (oC) 79 CH3 -O. 190 8o CH3 20t CH3 81 - \ 160 Cil30 82 178 HOOC 83 - \ 228 (with decoration, - position) CH) 8. 'n CH3 12b

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 TABLE III (Sute)
 EMI18.1
 Example R ci ?, R1 PJ \ ("C)! 85 in- 3) 148 Cfl 148 86 # (! 08 in8 87" 16elk 't ¯, ¯ ", i.



  88 "-0 N02 176
 EMI18.2
 Good results have. were obtained using the fungicidal compositions of the invention for coating seeds and Table IV below shows compounds which have been shown to be active against a number of bacterial and oryptogamous diseases of economic importance. . Similarly, Table V shows compounds active against certain fungal diseases of the foliage. The active constituents of the compositions tested are simply indicated by the numbers of the examples. tables I, II or III where they are presented.



  Seed Coating Agents
 EMI18.3
 T.'3LE! U IV.
 EMI18.4
 
<tb> Disease <SEP> Plant <SEP> ¯¯ <SEP> ¯ <SEP> Active <SEP> component <SEP> of
<tb> examples <SEP> n
<tb>
 
 EMI18.5
 Pythium ultin.um Peas 5th lle 16th 17, 79 and 81 rusnriua culmorum n 6, 7, 10, 26 and 81 Xanthoyionts s mu lya cenrunt Cotton 22
 EMI18.6
 
<tb> Tilletia <SEP> caries <SEP> Froment <SEP> 6, <SEP> 82 <SEP> and <SEP> 84
<tb>
 

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Foliage fungicides TABLE V.
 EMI19.1
 
<tb>



  Disease <SEP> Plant <SEP> Active <SEP> component <SEP> of
<tb> examples <SEP> n
<tb>
<tb> Piricularia <SEP> o <SEP> zae <SEP> Rice <SEP> 6, <SEP> 7, <SEP> 20, <SEP> 36 <SEP> and <SEP> 85
<tb>
 
 EMI19.2
 Viticultural Plasmopara Vine 7 Brysiphe cichoracearum Cucumbers 1, 7, 10, 81 and 84
 EMI19.3
 
<tb> Venturia <SEP> inaequalis <SEP> Apples <SEP> 7, <SEP> 19 <SEP> and <SEP> 81
<tb>
<tb> Alternarla <SEP> solani <SEP> Tomatoes <SEP> 34 <SEP> and <SEP> 79
<tb>
 
 EMI19.4
 Frysiphe Kraminis Oats 4 and 7
 EMI19.5
 
<tb> Botrytis <SEP> fabae <SEP> Beans <SEP> from <SEP> 19, <SEP> 26, <SEP> 39 <SEP> and <SEP> 79
<tb>
<tb> swamp
<tb>
      
The compounds of Examples 5, 6, 11, 16, 26 81 82 and 84 have been shown to be active against Rhizoctonia solani in soil.


    

Claims (1)

R E V E N D I C A T ION S. EMI19.6 ----, ----------------------- 1.- Fungicidal copposition characterized in that it comprises as active constituent a 2-isoxazoline-5- one of formula: EMI19.7 EMI19.8 where R represents a carboxymoth) 1e or earboj "4thyie radical, or an alkyl radical of 1 to 6 carbon atoms optionally bearing as a substituent a hydroxy or cyano radical or a halogen atom EMI19.9 ne and RI represents a phmyl or naphthyl substituted O \, no, and a carrier for the active component, which may be an inert diluent or a liquid diluent containing an agent. EMI19.10 ,,:, <;; 10- ac wJ.f. 2. - Composition according to claim 1, characterized 'in that the active component is a compound in which R is a methyl radical. 3. A composition according to claim 1 or 2, characterized in that the active component is a compound in which <Desc / Clms Page number 20> is a chloro-substituted phenyl radical, A composition according to claim 1 or 2, characterized in that the active component is a compound in which EMI20.1 R1 is a phenyl radical substituted by a lower alkyl radical. 5.- Fungicidal composition, characterized in that it comprises as active component -methyl-1-phenylhydrazone-2 isocazolin-5-one. 6.- Fungicidal composition, characterized in that it comprises as active constituent 3-methyl-4- (2'-methylphenyl-hydrazono) -2-isoxazolin-5-one. 7.- Fungicidal composition, characterized in that it EMI20.2 comprises as active ingredient 3-methyl-4- (2'-chlorophenylhydtazono) -2-isoxazolin-5-one. 8.- Fungicidal composition, characterized in that it EMI20.3 comprises as active component 3-methyl-4- (3'-chlorophenyl-hydrazono) -2-isoxazolin-5-one .. 9. - Fungicidal composition, characterized in that it EMI20.4 comprises as active component 3-methyl -!, .- (! '- chlorophenyl-hydrazono) -2-isoxazolin-2-one. 10.- Fungicidal composition, characterized in that it EMI20.5 comprises as active ingredient 3-methyl-4- (2-methyl -! '- chloro-;. phdnylhydrazono) -2-isoxazolin-5-one. 11.- Fungicidal composition, characterized in that it comprises, as active constituent, a salt of a 2-isoxazolin-5-one mentioned in one or other of the preceding claims. 12. - Fungicidal composition according to Clause 11, 'characterized in that the salt is a sodium or potassium salt. 13. Composition according to one or the other of claims 1 to 12, characterized in that the vehicle is a powdery inert solid diluent. EMI20.6 1 ..- Composition according to one or the other of the claims-'s tions 1 to 12, characterized in that the vehicle is a suitable non-phytotoxic liquid. 15.- A composition according to claim 13, character <Desc / Clms Page number 21> rized in that it contains a surfactant. 16.- A composition according to either of claims 1 to 15, characterized in that it contains a corrosion inhibitor. 17 Fungicidal composition for coating seeds, characterized in that it comprises a solution of sodium salt or EMI21.1 3-Nethyl -.- phnylhydrazono-2-isoxaolin-5-one potassium in a suitable non-phytotoxic solvent. 18. A fungicidal composition according to claim 17, characterized in that the sodium salt is present in an amount of about 25% weight / volume. 19 .. 2-Isoxazolin-5-one of the general formula EMI21.2 where R represents an alkyl radical of 2 to 6 and in particular of 2 to 4 carbon atoms, or.a carboxyalkyl or alkoxycarbonylalkyl radical having not more than 4 carbon atoms, and R1 represents a substituted phenyl or naphthyl radical or no. 20, - 2-Isoxazolin-5-one having the formula defined in claim 19 wherein R is an alkyl radical of 1 to 6 and in particular of 1 to 4 carbon atoms, or an inexpensive carboxyalkyl or alkoxycarbonylalkyl radical. more than 4 carbon atoms, and R1 is a chloro-substituted phenyl radical. EMI21.3 21.- 3-Methyl-4- (2e-chlorophenylhydrazono) -2-isoxazolin-5-one. 22.- 3-Methyl-4- (3'-chlotophônylhyàtazono) -2-isoxazoline-5-one, 23.- 3-mlthyl-4- (4'-chlorophlnylhydrazono) -2-1soxazoline- 5-one. 24.- Salt of a 2-isoxazolin-5-one according to one or EMI21.4 the other of claims 19 to 23. <Desc / Clms Page number 22> 25.- Process for the preparation of 2-isoxazoline-5-ones sui. according to claim 19 or 20, characterized in that a ketoester of formula is reacted; R - CO - CH2 - COOR3 where R has the meaning given to it in the claim 20, and R is an alkyl radical of 1 to 4 carbon atoms, with the EMI22.1 optional phlnyl- or naphthyldiazonium salt and hydroxylamine or a hydro salt 26. - Process for the preparation of 2-isoxazolin-5-ones according to claim 19 or 20, characterized in that an azo compound of formula is reacted: EMI22.2 where R and R3 have the meanings given to them in claim 25 and R1 represents a phenyl or naphthyl radical, substituted or not, with hydroxylamine or a salt of hydroxylamine. 27.- Modification of the process according to claim 22, characterized in that diketene is used instead of the keto ester. 28.- Process for the preparation of a 2-isoxazolin-5-one, in substance as described in Examples 1, 2, 34 35 or 40 29.- 2-Isoxazolin-5-one obtained by the process according to one or the other of claims 25 to 28. 30.- Fungicidal composition, characterized in that it comprises as active constituent the compound obtained in one or other of Examples 1 to 39. , 31. - Fungicidal composition, characterized in that it comprises as active constituent the compound obtained in one or the other of Examples 40 to 78-. 32.- Fungicidal composition, characterized.in that it. comprises as active constituent the compound obtained in either of Examples 79 to 88. 32. - Process for combating pathogenic organisms in plants, characterized in that the foliage is treated with a <Desc / Clms Page number 23> plant susceptible to these pathogens, the seed of the plant or the soil in which the plant is to grow with a fungicidal compound or composition $ in substance as described above with particular reference to the examples,