CH622784A5 - Process for the preparation of 1,4-diphenyl-3-pyrazolin-5-ones - Google Patents

Description

The invention relates to the field of agrochemistry and provides a method for producing new herbicidally active compounds. The growing of weeds, which is often referred to as growing plants where you don't want them, is known to have a detrimental effect on crops between which such weeds grow. Unwanted plants that grow in farmland or fallow land consume soil nutrients and water and deprive the crops of part of the sunlight. Weeds therefore leach the soil and cause measurable losses in crop yield.

The compounds of formula I mentioned later are new organic compounds. Some connections to these

5

10th

IS

20th

25th

30th

35

40

45

50

55

60

«5

Compounds related, however, are known in the herbicide field. For example, US Pat. No. 3,644,355 describes herbicidally active pyridazinones. In the field of agrochemistry, some herbicidally active pyrimidones are also known, such as the 6-alkyl-2,5-dihalogen-3-phenyl-4-pyrimidinones described in US Pat. No. 3,823,135.

There are also some diphenyl-5-pyrazolinones, such as those from Ber. 31,3164 (1898) known 3-methyl-1,4-diphenyl compound or the one described in Ber. 20, 2549 (1887) described 2-methyl-1,3-diphenyl compound. A pharmaceutically active pyrazolinone is 2,3-dimethyl-1-phenyl-3-pyrazolin-5-one, which is designated as an antipyrine and is an analgesic (Merck Index, 93, 8th edition 1968).

The invention now relates to a process for the preparation of new 1,4-diphenyl-3-pyrazolin-5-ones of the formula I.

0

R® 11 R1

• (^ / '(i)

R

wherein

R represents Ci-C3-alkyl and

R1 and R2 independently of one another are hydrogen, chlorine,

Fluorine, bromine, methyl or trifluoromethyl mean, with the proviso that the substituents R1 and R2 are not simultaneously hydrogen and that the substituent R1 also means no bromine or chlorine present in position 4, which is characterized in that a compound of Formula II

0

R \ »D1

./"V., V / ^ \

wherein the substituents R1 and R2 have the meanings given above, with an alkylating agent in the presence of a base.

The reason for the above measure is that compounds of the formula I which do not meet the stated measure are inactive.

Suitable alkylating agents and bases are alkyl halides, such as, for example, an alkyl iodide in the presence of a strong inorganic base or a dialkyl sulfate under strongly basic conditions. The above alkylation is best carried out at the reflux temperature of the reaction mixture. Alkylations of this type are common in the field of chemistry and have been described in the literature.

Ci-C3-alkyl in formula (I) above refers to methyl, ethyl or propyl.

Individual examples of compounds according to the invention from the above formula (I) are as follows:

4- (3-bromophenyl) -2-methyl-l-phenyl-3-pyrazolin-5-one, l- (3-chlorophenyl) -2-ethyl-4- (3-fluorophenyl) -

3-pyrazolin-5-one,

4- (3-chlorophenyl) -l- (2-fluorophenyl) -2-propyl-3-pyrazolin-5-one,

1,4-bis (3-bromophenyl) -2-methyl-3-pyrazolin-5-one,

622 784

2-propyl-l, 4-bis (m-tolyl) -3-pyrazolin-5-one, 4- (3-chlorophenyl) -2-methyl-l- (alpha, alpha, alpha-trifluoro-p-tolyl) -3-pyrazolin-5-one,

2-ethyl-l-phenyl-4- (m-tolyl) -3-pyrazolin-5-one, l- (3-chlorophenyl) -2-methyl-4- (m-tolyl) -3-pyrazolin-5- on,

1- (2-bromophenyl) -2-propyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one,

4- (3-chlorophenyl) -2-methyl-l- (o-tolyl) -3-pyrazolin-5-one, 4- (3-bromophenyl) -l- (2-chlorophenyl) -2-methyl-

3-pyrazolin-5-one,

2-ethyl-1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -

3-pyrazolin-5-one,

1- (3-fluorophenyl) -2-methyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one,

2-ethyl-l- (2-fluorophenyl) -4- (3-fluorophenyl) -

3-pyrazolin-5-one,

2-ethyl-l- (3-fluorophenyl) -4- (m-tolyl) -3-pyrazolin-5-one,

4- (3-bromophenyl) -l- (4-fluorophenyl) -2-propyl-

3-pyrazolin-5-one,

l- (2-bromophenyl) -4- (3-fluorophenyl) -2-propyl-

3-pyrazoIin-5-one,

1- (3-bromophenyl) -2-methyl-4- (m-tolyl) -3-pyrazolin-5-one,

2-methyl-4- (m-tolyl) -l- (alpha, alpha, alpha-trifluoro-

0-tolyl) -3-pyrazolin-5-one,

4- (3-fluorophenyl) -2-methyl-1- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one.

Preferred compounds of the formula (I) are those in which R is C 1 -C 2 -alkyl, R1 is hydrogen, chlorine or fluorine, with the proviso that R1 cannot be chlorine in position 4 and R2 is trifluoromethyl.

Preferred compounds according to the invention are as follows:

2-methyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-ethyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro -m-tolyl) -3-pyrazolin-5-one,

2-ethyl-1- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one,

2-ethyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (2-chlorophenyl) -4- (alpha, alpha, alpha-trifIuor-m-tolyl) - 3-pyrazolin-5-one,

1- (3-bromophenyl) -2-ethyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 1,4-bis (3-chlorophenyl) -2-ethyl -3-pyrazolin-5-oneimd

2-methyl-1- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one.

The production of the starting materials of the formula II required for the above process is best carried out by a two-stage process:

The first stage of this consists in the reaction of a methyl or ethyl ester of phenylacetic acid, which contains the respective substituent R2 on the phenyl ring, either directly with a dialkylformamide, dialkyl acetal of the dialkylformamide or using dimethylformamide as solvent, which gives an intermediate product receives a substituted ester of atropic acid of formula (III):

R \ 0

/ \ "

• • C CO alkyl (IX X)

\ / n

# * HC - N (AI kyl) 2

3rd

5

10th

15

20th

25th

30th

35

40

45

50

55

€ 0

65

622784

4th

îs analysis (%):

calculated: 64.15 found: 64.17

The statement alkyl contained in the above formula refers to methyl or ethyl. The reaction is carried out at temperatures of about 80 to 140 ° C in a reaction flask open to the atmosphere.

The intermediate of formula s (ffl) obtained in the above manner is then reacted with a phenylhydrazine or a hydrohalide thereof, which is optionally substituted on the phenyl ring by the respective substituent R1,

whereby the compound of formula (II) required as a starting material is obtained. io

If a phenylhydrazine is used in the form of its free base, the reaction is carried out in the presence of an aprotic solvent. Aromatic solvents such as benzene or toluene, aliphatic solvents such as hexane or octane and halogen-containing solvents such as methylene chloride or chloroform are suitable for this. Xylenes are preferred as solvents. The reaction is best carried out at the reflux temperature of the reaction mixture, but it is also possible, if appropriate, to work at other temperatures which can range from room temperature to 20 to about 120 ° C.

If one works using a phenylhydrazine hydrohalide, the reaction can be carried out in an aprotic solvent of the type described above in the presence of a base. Bases suitable for this purpose are tertiary organic amines, such as triethylamine, pyridine or triethanolamine, and inorganic bases, such as potassium carbonate,

Sodium carbonate or alkali hydroxides.

Corresponding reactions using phenylhydrazirihydrohalides can optionally also be carried out by first reacting the hydrazine with the intermediate of the formula (HI) in a lower alkanol at the reflux temperature of the reaction mixture and in this way the reaction of the compound of the formula (III) Exchange existing dialkylamino group for the arylhydrazine residue 35. The intermediate product obtained in this way ■

then cyclized by heating it in an aprotic solvent such as xylene to temperatures of about 50 to 120 ° C. Alternatively, the intermediate product obtained can also be cyclized by heating it to reflux temperature in a lower alkanol together with inorganic bases such as potassium carbonate, alkali metal hydroxides or alkali metal oxides.

All for the preparation of the compounds of the formula (IH)

raw materials used are known and easy «

accessible.

The invention is further illustrated by the following examples. All compounds contained therein are by analysis (%):

Magnetic nuclear magnetic resonance analysis and elemental microanalysis have been identified.

The reaction mixture is then cooled and the solids obtained are collected by filtration. In this way 2.6 g of l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one are obtained.

1.5 g of the above pyrazolinone are dissolved in 50 ml of methanol, and the solution is then mixed with 0.7 g of methyljo-did and with 0.7 g of potassium carbonate. The mixture is then heated to reflux temperature overnight. The mixture is then poured onto ice and the aqueous mixture is filtered. The product obtained is recrystallized from ethyl acetate-hexane. In this way, 0j85 g of 2-methyl-1-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tölyl) -3-pyr-azolin-5-one is obtained, which melts at 153 to 155 ° C .

H

4.12 4.19

N

8.80 8.77

Example 2

2-methyl-l-phenyl-4- (3-fluorophenyl) -3-pyrazolin-5-one 9 g of 3-fluorophenyl acetic acid methyl ester are reacted at a temperature of 120 ° C. with 6.5 g of dimethylformamide dimethyl acetal in 15 ml of dimethylformamide . In this way, 11.2 g of the corresponding methyl m-fluoratropasate are obtained. This ester is then reacted with 5.4 g of phenylhydrazine in 50 ml of toluene at the reflux temperature of 4 hours. An equal volume of m-xylene is then added and the reaction mixture is heated to reflux temperature overnight. The reaction mixture is then cooled and decanted, whereupon the solids obtained are treated with benzene and the whole is filtered again. The separated solids are then slurried in hot benzene-ethyl acetate, after which it is filtered again. Subsequent recrystallization of the resulting solids from ethanol gives 2.9 g of l-phenyl-4- (3-fluorophenyl) -3-pyrazolin-5-one, which melts at 189 ° C.

2.4 g of the above pyrazolinone are combined with 3.9 g of methyl iodide, whereupon the whole is reacted in the manner described in Example 1. After recrystallization of the product obtained from benzene-hexane, 1.5 g of 2-methyl-1-phenyl-4- (3-fluorophenyl) -3-pyrazolin-5-one, which melts at 134 ° C., is obtained.

example 1

2-methyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 10.9 g of 3-trifluoromethylphenylacetate are mixed 55 with 11.9 g of dimethylformamide dimethyl acetal, whereupon the mixture is heated on a steam bath overnight.

The reaction mixture is then taken up in methanol and the whole is poured onto ice. The resulting aqueous mixture is filtered and the solids 60 obtained are recrystallized from aqueous ethanol. In this way, 4 g of m-trifhiormethyl-ß- (dimethylamino) atropasäu-remethylester is obtained, which melts at 45 to 49 ° C.

The ester prepared above is combined with 1.6 g of phenylhydrazine in 25 ml of benzene, and the mixture is then heated to reflux temperature overnight. Then about 25 ml of p-xylene are added, whereupon the mixture is heated at reflux temperature for a further 2 hours.

calculated: found:

C.

71.63 71.35

H

4.88 5.01

N

10.44 10.17

Example 3

l-Phenyl-2-propyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 3 g of the pyrazolinone described in Example 1 and unsubstituted in position 2 are reacted with 10 ml of propyl iodide to give 0.45 g of l-phenyl-2-propyl-4- (alpha, alpha, al-pha-trifluoro-m-tolyl) -3-pyrazolin-5-one in the form of an oily liquid .

Analysis(%):

C H N

calculated: 65.89 4.95 8.09

found: 65.64 5.09 7.97

5

622 784

Example 4

2-ethyl-l-phenyl-4- (alpha, alpha, alpha, trifluoro-m-tolyl) -3-pyrazolin-5-one 2.5 g of the pyrazolinone described in Example 1 and unsubstituted in position 2 are treated with 1, 2 g of ethyl iodide reacted, whereby 1.2 g of 2-ethyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one is obtained, which is 156 to 157 ° C melts.

Analysis (%):

C H N

calculated: 65.06 4.55 8.43

found: 65.25 4.65 8.40

Example 5

2-methyl-l-phenyl-4- (3-chlorophenyl) -3-pyrazolin-5-one 17 g of 3-chlorophenylacetate are combined with 12 g of dimethylformamide dimethylacetal in 100 ml of dimethylformamide and the mixture thus obtained is then heated in an open reaction flask at boiling temperature for 6 hours. The hot reaction mixture is then poured onto ice, whereupon the aqueous mixture obtained is filtered. Subsequent recrystallization of the solids obtained in this way from benzene-hexane gives 13 g of methyl 3-chloratropate, which melts at 84 to 86 ° C.

4.8 g of the above intermediate is reacted with 2.2 g of phenylhydrazine, which gives 3.5 g of l-phenyl-4- (3-chlorophenyl) -3-pyrazolin-5-one, which is at 197 to 199 ° C melts.

2 g of the above intermediate are alkylated with 2.7 g of methyl iodide, giving 1 g of 2-methyl-l-phenyl-4- (3-chlorophenyl) -3-pyrazolin-5-one, which is at 149 to 150 ° C melts.

Analysis (%):

C H N

calculated: 67.49 4.60 9.84

found: 67.24 4.38 9.80

Example 6

2-methyl-1- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyr azolin-5 -one 5.5 g of the atropic acid ester from Example 1 are combined with 3, 5 g of 4-fluorophenylhydrazine hydrochloride and 2 g of triethylamine in 50 ml of benzene. The mixture is then stirred under reflux temperature for 5 hours, whereupon about half of the benzene present is allowed to evaporate and then an equivalent amount of m-xylene is added. The mixture is then stirred at reflux temperature overnight and then evaporated to dryness in vacuo. The residue is distributed between ethyl acetate and water, whereupon the organic layer is dried over sodium sulfate and evaporated to dryness. The residue is chromatographed on silica gel using ethyl acetate as the eluent. The product-containing fractions are combined and evaporated to dryness, giving about 3.5 g of crude product, the recrystallization of which from methanol gives 2.7 g of purified 1- (4-fluorophenyl) -4- (alpha, alpha, alpha- trifluoro-m-tolyl) -3-pyra-zolin-5-one leads, which melts at 171 to 173 ° C.

2 g of the above intermediate are then alkylated with 2.7 g of methyl iodide, which gives 1.6 g of 2-methyl-1- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) - 3-pyrazo-lin-5-one reaches, which melts at 165 ° C.

Analysis (%):

C.

H

N

calculated:

60.72

3.60

8.33

found:

60.99

3.58

8.32

Example 7

2-methyl-1- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 3.5 g of the atropic acid ester from Example 1 are added with 2.3 g of 3-chlorophenylhydrazine hydrochloride in the presence of 1.3 g of triethylamine in m-xylene according to the procedure described in Example 6. In this way, 2 g of l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one is obtained as the product, which melts at 182 to 184 ° C.

1.65 g of the above intermediate is then alkylated with 2 g of methyl iodide, which gives 1 g of 2-methyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) - 3-pyrazolin-5-one reaches, which melts at 130 to 131 ° C.

Analysis (%):

C H N

calculated: 57.89 3.43 7.94

found: 58.13 3.59 8.04

Example 8

2-Methyl-l- (m-tolyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 2.2 g of the atropic acid ester from Example 1 are added with 1.3 g of m-tolylhydrazine hydrochloride in the presence of triethylamine to give 1.7 g of l- (m-tolyl) -4- (alpha, alpha, al-pha-trifluoro-m-tolyl) -3-pyrazolin-5-one that melts at 158 to 159 ° C.

1.6 g of the above intermediate are then alkylated with 2 g of methyl iodide, which gives 1 g of methyl-1- (m-tolyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazoline- 5-one reaches, which melts at 153 to 154 ° C.

Analysis (%):

C H N

calculated: 65.06 4.55 8.43

found: 65.19 4.32 8.33

Example 9

2-methyl-1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 3.5 g of the atropic acid ester from Example 1 are mixed with 2.7 g of alpha, alpha, alpha-Trifhior-m-tolylhydrazine hydrochloride in the presence of triethylamine to give 2.4 g of 1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, which at 207 melts down to 208 ° C.

1.8 g of the above pyrazolinone is then reacted with 2 g of methyl iodide, which gives 1.25 g of 2-methyl-1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazoline 5-one reaches, which melts at 110 to 111 ° C.

Analysis (%):

C H N

calculated: 56.26 2.62 7.29

found: 56.04 2.86 7.19

s io

IS

20th

25th

30th

35

40

45

50

55

60

65

622 784

6

Example 10

2-Methyl-l- (2-chlorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one 2.7 g of the atropanoic acid ester from Example 1 are mixed with 1.8 g of 2-chlorophenylhydrazine hydrochloride in the presence of triethylamine, whereby 1 g of l- (2-chlorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one is obtained, which at 236 ° C melts.

1 g of the above pyrazolinone is then alkylated with 1 g of methyl iodide, which gives 0.45 g of 2-methyl-l- (2-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) - 3-pyrazolin-5-one reaches, which melts at 175 ° C.

Analysis (%):

C H N

calculated: 57.87 3.40 7.94

found: 57.39 3.51 7.93

10th

Example 11

2-ethyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-toIyl) -3-pyrazolin-5-one 2.6 g l- (3-chlorophenyl) -4- ( alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, prepared according to Example 7, is alkylated with ethyl iodide, whereby 0.25 g of 2 * -ethyl-1- (3-chlorophenyl ) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one in the form of an oily liquid.

20th

25th

Analysis (%):

calculated: found:

C.

58.95 58.89

H

3.85 3.61

N

7.64 7.52

Example 12

2-Ethyl-l- (3-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 15 g of the atropic acid ester from Example 1 are set at the reflux temperature over a period of about 2 days with 10 g of 3-fluorophenylhydrazine hydrochloride in methanol. The solvent is then evaporated off and the residue obtained is partitioned between ethyl acetate and water. The organic layer is separated and the residue is concentrated. The residue is recrystallized from a mixture of ethyl acetate and hexane, giving 2.1 g of a product with a melting point of about 172 ° C. This product is identified as l- (3-fluorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one.

2.1 g of the above pyrazolinone are added together with 15 ml of ethyl iodide and 1 g of potassium carbonate in 40 ml of ethanol, whereupon the reaction mixture obtained is heated to the reflux temperature for about 8 hours. The reaction mixture is then concentrated under vacuum and the residue is partitioned between ethyl acetate and water. The ethyl acetate layer is separated, dried and concentrated under vacuum, and the residue obtained is then chromatographed over a silica gel column using a mixture of ethyl acetate and hexane in a ratio of 1: 2. By isolating the material obtained in this way, 0.7 g of a product melting at about 140 to 141 ° C. is obtained. This product is identified as 2-ethyl-l- (3-fluorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one.

Analysis (%):

calculated: found:

C.

61.71

61.72

H

4.00 4.06

N

8.00 8.00

Example 13

2-ethyl-1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 4 g 1,4-bis (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one (according to Example 9) is heated to reflux temperature with 20 ml of ethyl iodide, 3 g of potassium carbonate and 40 ml of ethanol for about 4 hours. The reaction mixture is then concentrated under vacuum and the residue is extracted with ethyl acetate. The extract is dried over anhydrous magnesium sulfate, whereupon the drying agent is removed and the filtrate is concentrated under vacuum. When standing overnight, the residue solidifies. It is then recrystallized from a mixture of hexane and benzene. This material is then chromatographed using a mixture of ethyl acetate and hexane in a ratio of 1: 2 over a silica gel column. The product eluted from the column is then recrystallized from a mixture of hexane and benzene, whereby a product melting at about 110 to 111 ° C is obtained. This is identified as 2-ethyl-1,4-bis (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one.

Analysis (%):

C H N

calculated: 57.00 3.50 7.00

found: 56.63 3.49 6.85

Example 14

30 l- (3-bromophenyl) -2-ethyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one 13.7 g of the atropic acid ester of Example 1 are left at the reflux temperature React overnight with 11.2 g3-bromophenylhydrazine hydrochloride in 100 ml of methanol. The solvent is then evaporated off and the residue obtained is heated in reflux temperature in 100 ml of m-xylene and 5 g of triethylamine for about 16 hours. The reaction mixture is then concentrated under vacuum and the residue is chromatographed on a silica gel column using a 1: 1 mixture of ethyl acetate and hexane. In this way, 7.5 g of product are obtained, which is identified as l- (3-bromophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one.

7.5 g of the above pyrazoline are combined with 4 g of Kajium-45 carbonate and 15 ml of ethyl iodide in 100 ml of ethanol and the whole is heated in the same manner as described above for other similar compounds. This gives 2.0 g of a product with a melting point of about 106 ° C, which as l- (3-bromophenyl) -2-ethyl-4- (alpha, i.e. pha, alpha-trifluoro-m-tolyl) -3 -pyrazolin-5-one is identified.

Analysis (%):

ss "calculated: found:

Example 15

2-ethyl-1- (4-fluorophenyl) -4-alpha, alpha, alpha-trifluoro-60 m-tolyl) -3-pyrazolin-5-one

6 g of l- (4-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one (prepared according to Example 6) are mixed with 4 g of potassium carbonate and 15 ml of ethyl iodide in 100 ml of ethanol and then heat the whole thing to reflux temperature overnight. The usual isolation below gives 1.8 g of product with a melting point of about 92 ° C., which is 2-ethyl-l- (4-fluorophenyl) -4-alpha, alpha, alpha-trifhior-m-tolyl) -3 -pyrazolin-5-ön is identified.

*

c

H

N

52.57

3.43

6.81

52.80

3.49

6.98

7

622 784

Analysis (%):

C H N

calculated: 61.72 4.03 8.00

found: 61.87 4.20 8.06

Example 16

1,4-bis (3-chlorophenyl) -2-ethyl-3-pyrazolin-5-one 12 g of 3-chloratropasate (prepared according to Example 5) are added with 10 g of 3-chlorophenylhydrazine hydrochloride in 100 ml of methanol overnight Reflux temperature around. This gives 10 g of a product with a melting point of about 173 to 174 ° C, which is identified as 1,4-bis (3-chlorophenyl) -3-pyrazolin-5-one.

A mixture of 7 g of the pyrazolinone prepared above, 4 g of potassium carbonate and 15 ml of ethyl iodide in ethanol is heated to reflux temperature overnight. After recrystallization of the resulting material from ether, 3.0 g of product with a melting point of about 101 ° C., which is called 1,4-bis (3-chlorophenyl) -2-ethyl-3-pyrazo-lin-5- on is identified.

Analysis (%):

C H N

calculated: 61.28 4.24 8.41

found: 61.04 4.21 8.55

Example 17

4- (3-chlorophenyl) -2-ethyl-l- (alpha, alpha, alpha-trifluoro-

m-tolyl-3-pyrazolin-5-one A mixture of 12 g of 3-chloratropaic acid methyl ester (prepared according to Example 5), 13 g of m-trifluoromethylphenylhydrazine hydrochloride and 100 ml of methanol is heated to reflux temperature overnight, giving 4.6 g of a product melting at about 190 192 ° C, which is identified as 4- (3-chlorophenyl) -l- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one.

A mixture of 4.6 g of the pyrazolinone prepared above, 4 g of potassium carbonate, 15 ml of ethyl iodide and 50 ml of ethanol is heated to reflux temperature overnight. By customary working up of the reaction mixture obtained in this way, 1.8 g of a product which melts at about 113 to 114 ° C. and is obtained as 4- (3-chlorophenyl) -2-ethyl-1- (alpha, alpha, alpha-trifluoro) m-tolyl) -3-pyrazolin-5-one is identified.

Analysis (%):

C H N

calculated: 58.95 3.85 7.64

found: 58.84 3.89 7.63

Example 18

l- (3-chlorophenyl) -2-ethyl-4-phenyl-3-pyrazolin-6-one 120 g of methyl phenylacetate are combined with 95 g of dimethylformamide dimethylacetal in 200 ml of dimethylformamide and the whole is then gently heated to the reflux temperature for about 4 days, 5 g of dimethylformamide are added at appropriate intervals until a total of 140 g have been added. At the end of this heating period, the reaction mixture is allowed to come to room temperature and then poured onto crushed ice. The oily product obtained is separated off and optionally crystallized. The crystalline product is washed with water, cooled in the refrigerator, filtered off and air-dried. By recrystallizing this crude product from cyclohexane, a product which melts at about 58 to 60 ° C. is obtained and is identified as methyl ß- (dimethylamino) atropate.

Analysis (%):

C H N

calculated: 70.22 7.37 6.82

found: 70.47 7.36 6.85

A mixture of 10.5 g of the above methyl atropate, 9.1 g of 3-chlorophenylhydrazine hydrochloride and 200 ml of methanol is heated to reflux temperature overnight. The reaction mixture is then worked up in a conventional manner, which gives 11 g of crude l- (3-chlorophenyl) -4-phenyl-3-pyrazolin-5-one. By recrystallizing a sample thereof from methanol, a material with a melting point of approximately 211 to 212 ° C. is obtained.

A mixture of 4 g of the pyrazolinone prepared above, 20 ml of ethyl iodide, 20 ml of ethyl bromide, 3 g of potassium carbonate and 40 ml of ethanol is heated to the reflux temperature for about 4 hours. The subsequent customary work-up of the reaction mixture gives 0.9 g of an oil which is identified as l- (3-chlorophenyl) -2-ethyl-4-phenyl-3-pyrazolin-5-one.

Analysis (%):

C H N

calculated: 68.34 5.06 9.38

found: 68.15 4.89 9.29

Example 19

■ 2-ethyl-4-phenyl-1- (adpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one

A mixture of 8.2 g of methyl atropate (prepared according to Example 18), 8.5 g of m-trifluoromethylphenylhydrazine hydrochloride, 100 ml of benzene and 4 g of triethylamine is heated to reflux temperature overnight and then worked up in a conventional manner. In this way, 6.5 g of 4-phenyl-1- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one are obtained, which melt at about 210 to 213 ° C.

A mixture of 2.2 g of the above pyrazolinone, 2 g of potassium carbonate, 25 ml of ethyl iodide and 25 ml of ethanol is heated to the reflux temperature for about 3 hours. The subsequent customary work-up of the reaction mixture gives an oil which, by means of the NMR spectrum, is 2-ethyl-4-phenyl-l- (aplha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazoline-5 -one is identified.

The compounds of the formula I have been investigated to determine the range of their herbicidal activity in a number of herbici test systems. The results obtained using typical compounds according to the invention show the herbicidal activity of these compounds.

The application amounts for the compounds according to the invention are expressed in kilograms of active ingredient per hectare of soil (kg / ha).

Blank spaces in the following tables mean that the respective compound has not been tested for the specified species. The plants are assessed in the following tests on a rating scale ranging from 1 to 5, the number 1 standing for normal plants and the number 5 dead plants or no emergence at all. The compounds are identified by their respective sample numbers.

s

10th

15

20th

25th

30th

35

40

45

50

55

60

65

622784

Experiment 1 Investigation of broadband effects

Square plastic pots are filled with sandy sterile greenhouse soil and sown with seeds for tomatoes, millet and field foxtail. Each pot is fertilized individually.

Some pots are treated with the compounds to be tested after emergence and others before emergence. The post-emergence treatment with the active substances according to the invention is carried out by spraying over the emerged plants about 12 days after sowing the seeds. The pre-emergence treatment is carried out by spraying the active ingredients onto the soil the day after the seeds are sown.

Each compound to be tested is dissolved in a 1: 1 mixture of acetone and ethanol in an amount of 2 g per 100 ml. The individual solutions further contain about 2 g of a mixture of an anionic nonionic surface active agent per 100 ml solution. 1 ml of the solution obtained in this way is then diluted to 4 ml with deionized water, and spraying 1.5 ml of the solution thus obtained onto each pot gives an application amount of 16.8 kg for the compound to be investigated per hectare

After the active ingredients according to the invention have been applied, the pots are placed in the greenhouse and irrigated according to the particular need. The plants are examined and assessed about 10 to 13 days after the active ingredient has been applied. Untreated control plants are used as standard in each experiment.

The results obtained in the investigation of typical compounds of the formula I according to the invention are summarized in Table I below.

Table I

Yasseree

Post-emergence

connection

Blood-

Field

blood

Arable

of example

To finger

Fox- ;

To finger

- Fox

5 no.

Mate millet tail Mate millet tail i

3rd

4th

4th

4th

3rd

2nd

2nd

5

5

5

5

5

5

4th

5

5

5

4th

4th

4 -

5

4th

5

5

5

5

5

10 6

4-

.5

4th

3rd

4th

4th

7

3rd

4th

4th

5

3rd

5

8th

3rd

4th

3rd

4th

4th

3rd

9

2nd

5

5

2nd

3rd

3rd

15 Trial 2

Greenhouse studies on a number of weeds These studies are generally carried out in exactly the same way as the studies described above. 20 However, the seeds are not planted in pots, but in metal pricking boxes. The formulation of the active ingredients is carried out according to the method described above, but in deviation from this, 6 g of active ingredient are dissolved in 100 ml of the solvent containing the surface-active agent, and this solution is prepared before. Apply to the pricking boxes diluted with appropriate amounts of water. The compounds are used in the various amounts shown in Tables H and HI below, and the results obtained on testing against the following plant species are also shown in these Tables. If more than one test is carried out, the test results are averaged.

Table!!

Connection of example no.

Application quantity in kg / ha

Corn

cotton

Soybean

wheat

alfalfa

sugar beet

rice

cucumber

tomato

Chicken millet Ë

ST £

White goosefoot

Chickweed

mustard

Arable

fox tail

Forage millet

Ì

Wind oat i

Indian mallow

Common thorn apple

Purple winds

Zinnia.

1

0.56

1

i

1

2nd

i i

•1

i i

2 4

4th

2nd

2nd

2nd

2nd

i

1

1

i

2.2

2nd

i

1

3rd

i

2nd

1

i i

5 5

5

; 5

5

3rd

2nd

2nd

3rd

4th

2nd

9.0

2nd

4th

. 3rd

4th

2nd

3rd

2nd

2nd

9.0

2nd

5

5

4th

5

4th

- 5th

3rd

1.1

1

i

1

2nd

i

2nd

2nd

2nd

i

3 2

3rd

3rd

3rd

3rd

2nd

1

1

1

1

4.5

2nd

i

1

4th

2nd

4th

2:

2nd

3rd

-5. 4 -

5

4th

5

4th

1

2nd

2nd

1

1

4th

1.1

3rd

i

2nd

3rd

2nd

4th

2nd

3rd

3rd

4 4

5

4th

- 4th

3rd

3rd

3rd

3rd

2nd

2nd

9.0

4th

5

4,

5

4th

4th

2nd

5

9.0

2nd

5

5

4th

4th

2nd

3rd

6

1.1

2nd

i

1

2nd

2nd

2nd

1

2nd

2nd

3 5

5:

4th

4th

4th

2nd

2nd

1

1

1

4.5

3rd

i

2nd

4th

3rd

4th

1

2nd

3rd

5 5

5

5

5

5

3rd

2nd

2nd

2nd

2nd

9.0

3rd

5

5

4th

3rd

3rd

1

7

1.1

2nd

i

1

2nd

1

1

1

1

2:

3 4

5 '

3rd

4th

3rd

3rd

2nd

2nd

2nd

1

4.5

3rd

1

2nd

2nd

3rd

2nd

4th

3rd

4 4

5

4th

5 '

4th

3rd

3rd

3rd

3rd

2nd

9.0

2nd

4th

4th

4th

3rd

2nd

2nd

8th

1.1

1

i

1

1

1

2nd

1

1

1

2 2

4th

2nd

3rd

2nd

2nd

2nd

2nd

1

2nd

4.5

2nd

i

1

2nd

2nd

3rd

1

4th

3rd

3 5

5

4th

5

3rd

3rd

3rd

3rd

2nd

2nd

9.0

1

.5

5

4th

3rd

2nd

1

9

9.0

2nd

5

4th

4th

2nd

1

1

10th

2.2

1

i

1

1

2nd

1

- 2nd

5

2nd

2 4

4th

3rd

3rd

3rd

1

1

1

1

2nd

4.5

1

i

2nd

1

2nd

2nd

2nd

4th

3rd

4 4

5

4th

5

3rd

1

2nd

4th

2nd

3rd

11

2.2

4th

i

3rd

5

5

3rd

3rd

4th

4 ■ 5

5

5

5

5

4th

4th

4th

4th

3rd

9.0

4th

5

5

5

5

4th

4th

12

0.28

1

i

1

1

1

1

1

1

2nd

1 1

3rd

1

2nd

2nd

1

2nd

1

1

1

0.56

1

i

1

1

3rd

3rd

1

3rd

3rd

3 3

3rd

2nd

2nd

3rd

1

1

1

1

1

1.1

2.5

i

1.5

2.5

2nd

3rd

1.5

1

2.5

3.5 4.5

4.5

3rd

4th

4.5

2nd

2.5

1.5

1

1

Table II (continued)

c

Pre-emergence

Connection of example no.

Application quantity in kg / ha

Corn

cotton

Soybean

wheat

alfalfa

Sugar beet

'5

cucumber

Tornate u

V.

IE u (= x:

: 3

I.

White Günsefuss

Blood finger millet

mustard

Field foxtail

Forage millet

Wind oat

Indian mallow

Common Stechapfcl

Purple winds

zinnia

2.2

3rd

i

3rd

3rd

5

5

2nd

2nd

3rd

5

5

5

5

5

5

4th

4th

2nd

2nd

2nd

4.5

3rd

i

3rd

4th

5

5

3rd

3rd

3rd

5

4th

5

5

5

5

4th

4th

2nd

2nd

2nd

9.0

2nd

5

4th

5

3rd

2nd

2nd

13

0.28

1

i

1

2nd

2nd

3rd

1

1

1

3rd

2nd

1

2nd

4th

2nd

1

2nd

1

3rd

1

0.56

2nd

i

1

2nd

3rd

3rd

1

2nd

2nd

3rd

3rd

4th

2nd

5

3rd

3rd

3rd

2nd

2nd

2nd

1.1

2.5

1.5

1

2.5

3rd

3rd

1

1.5

2.5

3.5

4.5

5

3.5

5

4th

3rd

2.5

1.5

2.5

2nd

2.2

3rd

1

1

2nd

3rd

4th

1

1

3rd

4th

5

4th

3rd

5

4th

3rd

3rd

2nd

2nd

3rd

4.5

3rd

1

1

3rd

4th

4th

1

1

2nd

4th

5

5

4th

5

4th

3rd

3rd

3rd

3rd

2nd

9.0

3rd

4th

5

4th

3rd

3rd

2nd

14

0.28

2nd

1

1

2nd

2nd

3rd

2nd

1

2nd

2nd

3rd

4th

5

3rd

3rd

4th

1

2nd

1

1

0.56

2nd

1

1

2nd

4th

3rd

1

1

2nd

3rd

4th

4th

3rd

4th

5

2nd

3rd

2nd

2nd

2nd

1.1

2nd

1

2nd

2nd

2nd

4th

2nd

3rd

3rd

4th

3rd

4th

4th

4th

4th

3rd

2nd

2nd

3rd

2nd

2.2

3rd

2nd

2nd

3rd

3rd

4th

2nd

3rd

2nd

4th

5

5

4th

5

4th

3rd

3rd

3rd

4th

3rd

4.5

3rd

2nd

2nd

3rd

3rd

4th

2nd

3rd

3rd

4th

5

5

4th

5

5

3rd

4th

3rd

4th

4th

9.0

3rd

4th

5

4th

4th

3rd

3rd

15

0.07

2nd

1

1

1

1

2nd

1

1

1

2nd

3rd

4th

2nd

3rd

4th

1

1

1

1

1

0.14

2nd

1

1

2nd

2nd

4th

1

1

1

2nd

4th

4th

2nd

4th

4th

2nd

1

1

1

1

0.28

2.5

1

1.5

2nd

2.5

4th

1

1

2nd

3.5

4.5

5

3rd

4.5

5

2.5

3rd

2nd

1

1

0.56

3rd

1

1

4th

3rd

3rd

'2

1

3rd

4th

4th

5

4th

5

5

3rd

3rd

2nd

2nd

3rd

1.1

3.5

1

2nd

3.5

3rd

3.5

2.5

1.5

5

5

5

5

4.5

5

5

2nd

3rd

3rd

2nd

1

2.2

4th

2nd

2nd

4th

4th

5

3rd

3rd

4th

5

5

5

5

5

5

3rd

5

5

3rd

3rd

4.5

4th

2nd

4th

4th

4th

4th

5

3rd

4th

5

5

5

5

5

5

5

4th

4th

3rd

2nd

9.0

4th

5

5

5

4th

3rd

3rd

16

0.07

1

1

1

1

1

2nd

1

1

1

2nd

2nd

2nd

2nd

1

3rd

1

2nd

1

1

1

0.14

2nd

1

1

2nd

2nd

2nd

2nd

1

2nd

2nd

3rd

4th

2nd

2nd

4th

2nd

1

1

1

1

0.28

1.5

1

1

2nd

2nd

2nd

1.5

1

2nd

3.5

3.5

4.5

2.5

2.5

4.5

1.5

2.5

1.5

1.5

1.5

0.56

2nd

1

1

2nd

3rd

3rd

1

1

2nd

4th

4th

5

3rd

3rd

5

2nd

2nd

1

1

2nd

1.1

2.5

1

2nd

3rd

3rd

4th

1.5

2.5

3.5

4th

3rd

4.5

3rd

4th

5

2.5

2.5

2.5

2nd

2nd

2.2

3rd

1

2nd

4th

3rd

5

2nd

2nd

3rd

4th

4th

5

4th

5

5

3rd

4th

3rd

4th

3rd

4.5

4th

2nd

3rd

4th

3rd

5

3rd

4th

4th

4th

4th

5

4th

5

5

3rd

4th

3rd

4th

3rd

9.0

4th

5

5

5

4th

3rd

4th

17th

1.1

2nd

1

1

2nd

1

2nd

1

1

1

3rd

3rd

4th

2nd

3rd

3rd

2nd

2nd

1

1

1

2.2

2nd

1

1

2nd

2nd

4th

1

2nd

1

4th

3rd

4th

3rd

4th

4th

2nd

2nd

2nd

2nd

1

4.5

3rd

1

1

3rd

2nd

2nd

1

2nd

2nd

4th

4th

5

3rd

4th

4th

3rd

3rd

2nd

2nd

2nd

9.0

3rd

4th

5

4th

4th

3rd

2nd

18th

0.28

2nd

1

i

2nd

1

3rd

1

1

2nd

2 *

3rd

4th

1

2nd

4th

1

1

1

1

1

0.56

2nd

1

1

2nd

2nd

4th

1

1

3rd

3rd

4th

4th

1

2nd

3rd

1

2nd

1

2nd

1

1.1

3rd

1.5

2nd

2.5

3rd

4th

1.5

2nd

2nd

4th

4th

4.5

3rd

3.5

5

2nd

2nd

1.5

2.5

2nd

2.2

4th

1

1

3rd

4th

5

1

1

3rd

4th

5

5

4th

3rd

5

3rd

3rd

1

2nd

3rd

4.5

4th

2nd

3rd

4th

5

5

3rd

3rd

5

5

5

5

5

5

5

3rd

4th

2nd

4th

4th

9.0

4th

5

5

5

5

3rd

2nd

19th

1.1

3rd

1

1

2nd

2nd

3rd

1

1

2nd

2nd

4th

4th

3rd

3rd

3rd

2nd

2nd

1

1

1

2.2

2nd

1

1

2nd

2nd

2nd

2nd

1

2nd

3rd

5

5

4th

5

5

2nd

3rd

2nd

1

1

4.5

3rd

1

1

3rd

5

5

2nd

1

3rd

4th

5

5

3rd

5

5

2nd

3rd

2nd

3rd

2nd

9.0

3rd

4th

5

5

3rd

4th

2nd

Table III

Post-emergence

Connection On- Blood- Field- India-

from example- finger- fox- lining- purple-

No quantity corn millet tail millet mallow winds zinnia

2 9.0 2 3 22233

4 9.0 2433322

5 9.0 2 2 21 1 1 1

6 9.0 1 2 2 1 1 1 1

7 9.0 2443333

8 9.0 1 4 3 2 '2 2 2

9 9.0 2231122

622784

10th

Table III (continued)

Post-emergence

connection

On

blood

Field

India

from example carry finger

Fox

Food

niche-

purple

No.

amount

Corn millet swan?

millet

Mallow winds

zinnia

11

13

14

15

16

17th

18th

9.0 9.0 9.0 9.0 9.0 9.0 9.0

2 2 2 2 2 2 2

Experiment 3 can be determined. The connections are made according to the

Investigations against resistant weeds Formulated and dispersed data from experiment 1 above,

Typical compounds are examined when the dispersions obtained are applied accordingly.

system through which the ability of these active ingredients is carried. The application amount for all of these tests to reduce the strength and vitality of weeds is 20 to 9.0 kg / ha, and the results obtained are shown in Table IV below, which are resistant to a number of herbicides.

Table IV

Pre-emergence

Post-emergence

connection

of example

Yellow

night

Canadian

Ambrosia

Yellow

No.

Cyprus grass shade

Gooseberry herb

Cyprus grass

1

1

4th

2nd

4th

2nd

4th

4th

5

4th

4th

4th

5

2nd

5

3rd

2nd

1

6

4th

4th

2nd

4th

2nd

7

4th

4th

2nd

3rd

2nd

8th

3rd

4th

2nd

3rd

1

The test results show the effectiveness of the compounds according to the invention against annual grasses, the relatively easy to control broad-leaved plants, such as arable fox tail, and the more resistant broad-leaved weeds, such as the nightshade family. It can be seen from the effects stated for the individual compounds that these compounds can be used as broad-band herbicides for undesired herbaceous plants, which are abbreviated as weeds.

The above test results also show that the active compounds according to the invention can be used to reduce the vitality of weeds by combining them with a herbicidally effective amount of one of these compounds. A reduction in vitality is understood to mean both killing and damage to the weed treated with the active ingredient. According to the above test results, in some cases, the entire population of the entire weeds treated is killed. In other cases, only one part of the weeds is killed, while another part of it is only damaged. Furthermore, treatment of this type means that no plants can die at all, but only damage. A reduction in the strength of growth or vitality of the weed population due to damage to some of these plants is of course already associated with a benefit, even if some of the weed population survives the treatment with active ingredients. Such weeds, which are impaired in their strength and vitality, are extraordinarily sensitive to unfavorable conditions to which the plants are normally exposed, such as plant diseases, drought or a lack of nutrients.

40

45

50

The treated plants, therefore, although they initially survive the treatment with active ingredient, can hardly withstand the above unfavorable conditions. If the treated weeds also grow on farmland, then the normal further growth of the crop plants causes them to take the sun away from the treated weeds, which are weakened in their strength. This gives the crops a significant advantage over the treated weeds in the competition for nutrients and sunlight. If the treated weeds also grow on fallow land or on industrial premises that are supposed to be clean, then the reduction in the strength of the weeds inevitably leads to minimal consumption of water and nutrients by these treated weeds, which also increases the risk of fire and nuisance the existing weeds are reduced.

The active compounds according to the invention are active both when pre-emergence and after-emergence herbicid 55. They can therefore be used either by direct contact of these active ingredients with weeds that have sprung up or by soil application, as a result of which they come into contact with the germinating and emerging weeds. A pre-emergence application of the active compounds according to the invention in which the germinating and emerging plants come into contact with the active compound by soil application is preferred.

An important embodiment of the invention is therefore a method for reducing the strength and vitality of weeds, which consists in combining the respective 65 weeds with a herbicidally effective amount of a compound of the formula (I) given above.

Herbicidally effective amount is understood to mean that amount which leads to a reduction in vitality and

Strength of treated weeds leads. Weed seeds that are brought together with the active compounds according to the invention by soil application are considered to be weeds.

The amount of herbicide used is expressed by the weight of the herbicide applied per unit area, which is usually referred to as the amount applied. The optimum application amount of a particular compound of formula (I) for controlling a particular weed varies, of course, depending on the climate, the type of soil, the soil content of water and organic material and other factors as are known to the plant expert. However, the optimal application rate is usually in the range of about 0.5 to 20 kg / ha.

Of course, not all compounds of formula (I) are effective against all weeds in all application quantities. Some compounds are more effective against some types of weeds, while other compounds are more effective against other types of weeds. However, all of the compounds according to the invention act at least against some weeds. Finding the weeds that can be controlled most cheaply with the various compounds, and the best application amounts for each, is no problem for the plant specialist.

The active compounds according to the invention are applied in a customary manner to the soil to be treated or to the weeds which have accumulated. It is best to use the compounds according to the invention in the form of herbicidal preparations which are important embodiments of the invention. They can be applied to the floor in the form of water-dispersed or granular preparations. Preparations dispersed in water are usually used for treating weeds with the active compounds. The application of the preparations can be achieved with any spray device or a granule application device, as is customary for the distribution of agrochemicals onto the soil or onto vegetation. In general, the preparations according to the invention are formulated in a manner customary in agrochemistry.

The compounds are often also formulated in the form of concentrated preparations, which are then applied to the soil or the foliage in the form of aqueous dispersions or emulsions with active compound contents of about 0.1 to 5%. The water-dispersible or emulsifiable preparations are either solids known as wettable powders or represent liquids known as emulsifiable concentrates. The wettable powders consist of an intimately finely divided mixture of the respective active ingredient, an inert carrier and surface-active agents. The drug concentration is usually 10 to 90%. As inert

622 784

Carriers are usually used in attapulgite clays, montmorillonite clays, kaolin clays, diatomaceous earths or purified silicates. Suitable surfactants which make up about 0.5 to 10% of the wettable powder are, for example, sulfonated lignins, condensed naphthalenesulfonates, naphthalenesulfonates, alkylbenzenesulfonates, alkyl sulfates or nonionic surfactants, such as adducts of ethylene oxide and phenol.

Typical emulsifiable concentrates of the active compounds according to the invention contain a suitable concentration of the respective compound, for example an amount of about 100 to 500 g per liter of liquid, in the form of a solution in an inert carrier, which is a mixture of a water-immiscible solvent and emulsifiers. Examples of suitable organic solvents are aromatic solvents, in particular the xylenes, or petroleum fractions, in particular the high-boiling naphthaic or olefinic fractions of petroleum. Various other organic solvents can also be used, such as the terpene solvents or the complex alcohols, such as 2-ethoxyethanol. The same surface-active agents can be used as emulsifiers for the production of emulsifiable concentrates as are also used for the production of wettable powders.

If a certain active ingredient is to be used to treat the soil and thus be used, for example, before the plants emerge, it is advisable to use a granular formulation for this purpose. Such a formulation usually contains the respective active ingredient in a form distributed on a granular inert carrier, such as roughly ground clay. The particle size of the granules is usually about 0.1 to 3 mm. Granules of this type are normally formulated by dissolving the respective active ingredient in a cheap solvent and then treating the carrier with the solution obtained in this way in a suitable solid mixer. However, the compound can also be distributed in a dough-like mass of moist clay or another inert carrier and then the whole thing can be dried and roughly ground to produce the desired granulate. However, this approach is less economical.

It has become common in agrochemistry to use two or even more agrochemicals at the same time in order to control weeds of all kinds or weeds and other pests at the same time by means of a single chemical treatment. The compounds of formula (I) according to the invention can now also be combined with such other agrochemicals. They can be combined with insecticides, fungicides, nematocides or other herbicides as required.

11

s

10th

15

20th

25th

30th

35

40

45

50

B

Claims (2)

622 784 2 PATENT CLAIMS 1- (3-bromophenyl) -2-ethyl-4- (alpha, alpha, -alpha-trifhior-m-tolyl) -3-pyrazolin-5-one, 1- (3-bromophenyl) -2-ethyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 1,4-bis (3-chlorophenyl) -2-ethyl -3-pyrazolin-5-one. 8. Use of the herbicidal active ingredient of the formula I for reducing the strength and vitality of weeds, characterized in that such weeds are brought together with a herbicidally effective amount of this herbicidal composition. 9. Use according to claim 8, characterized in that the compound used is a compound of the formula I in which R is Ci-C2-alkyl, R1 is hydrogen, chlorine or fluorine, with the proviso that R1 is not in position 4 chlorine present, and R2 represents trifluoromethyl. 10. Use according to claim 8, characterized in that one of the following compounds of the formula I is used as active ingredient: 2-methyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-ethyl-l-phenyl-4- (aIpha, alpha, alpha-trifluor -m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (4-fluorophenyl) -4- (alpha, alpha, -alpha-trifluoro-m-tolyl) -3 -pyrazolin-5 -one , 2-methyl-l- (3-chlorophenyl) -4- (alpha, alpha, -alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (2-chlorophenyl) - 4- (alpha, alpha, -alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-ethyl-l- (3-chlorophenyl) -4- (alpha, alpha, -alpha-trifluor-m -tolyl) -3-pyrazolin-5 -one, 1. Process for the preparation of 1,4-diphenyl-3-pyrazolin-5-ones of the formula I. 0 R \ "K1 / * ~ \ / \ / X \ _ / m r \ - / ■ »• N • • \ (I) wherein R represents Ci-C3-alkyl and R1 and R2 independently of one another are hydrogen, chlorine, Fluorine, bromine, methyl or trifluoromethyl, with the proviso that the substituents R1 and R2 do not simultaneously represent hydrogen and that the substituent R1 also does not mean any bromine or chlorine present in position 4, characterized in that a compound of the formula II 0 R2 "R1 \ = / l — L \ = / (ID wherein the substituents R1 and R2 have the meanings given above, with an alkylating agent. 2. The method according to claim 1 for the preparation of 2-ethyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, characterized in that l-phenyl- 4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one is reacted with ethyl iodide. 3. The method according to claim 1 for the preparation of 2-methyl-l- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tol-yl) -3-pyrazolin-5-one, characterized in that that l- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazo-lin-5-one is reacted with methyl iodide. 4. Herbicides agent from an inert carrier and an active ingredient, characterized in that it is a 1,4-diphenyl-3-pyrazolin-5-one of the formula I as active ingredient 0 R2 \ "_ X / \ - / \ =. / || __i \ = / (I> wherein the substituents R, R1 and R2 have the meanings given in claim 1. 5. Composition according to claim 4, characterized in that it contains the active ingredient in a concentration of 10 to 90 percent by weight. 6. Composition according to claim 4 or claim 5, characterized in that it contains as active ingredient a compound of formula I, wherein R is Ci-C2-alkyl, R1 is hydrogen, chlorine or fluorine, with the proviso that R1 is not in Position 4 can be chlorine, and R2 represents trifluoromethyl. 7. Composition according to claim 4, characterized in that it contains one of the following compounds of formula I as active ingredient: 2-methyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-ethyl-l-phenyl-4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (4-fluorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 2-methyl-l- (2-ehlorphenyl) -4- (alpha, alpha, alpha-trifluoro-m-tolyl) - 3-pyrazolin-5-one, 2-ethyl-l- (3-chlorophenyl) -4- (alpha, alpha, alpha-trifhior-m-tolyl) -3-pyrazolin-5-one, 2-Ethyl-1- (4-fluorophenyl) -4- (alpha, alpha, -alpha-trifluoro-m-tolyl) -3-pyrazolin-5-one, 1,4-bis (3-chlorophenyl) -2- ethyl 3-pyrazolin-5-one.