JPS5835186B2 - 4- Benzoylpyrazole - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula (where R represents a lower alkyl group or a lower alkenyl group, R2 represents a lower alkyl group, and X represents a halogen atom or a lower alkyl group).

n represents an integer from 1 to 3, and when n is 2 or 3,
may be the same or different from each other.

) and a method for producing the aluminum salt thereof.

In the general formula (I), R1 is preferably a linear or branched lower alkyl group having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl or isopropyl, or 1-methyl2 - Represents a linear or branched lower alkenyl group having 3 or 4 carbon atoms, such as propenyl or allyl.

R2 preferably represents a linear or branched lower alkyl group having 1 to 3 carbon atoms as exemplified for R1.

X preferably has a halogen atom such as a chlorine atom, a bromine atom, an iodine atom or a fluorine atom, or has 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl. Represents a linear or branched lower alkenyl group, n is 1
to 3, and when n is 2 or 3, X may be the same or different.

The compounds having the general formula (I) and their aluminum salts obtained by the method of the present invention are useful as herbicides or intermediates for herbicide synthesis.

Particularly useful compounds in the general formula (I) are such that R1 represents a methyl group or an allyl group, R2 represents a methyl group, X represents a chloro atom or a methyl group, n represents 1 to 3, and n represents When 2 or 3, X may be the same or different.

Particularly preferred is the case where Xn is 24-dichloro.

Aluminum salts of general formula (I) above are useful as well.

The compound of general formula (I) can exist in the following tautomeric form.

(In the formula, R1, R2, X and n are the same as above) ■3-dimethyl-4-(2-chlorobenzoyl)-5
-Hydroxypyrazole and 1,3-dimethyl~4-
(4-Nitrobenzoyl)-5-hydroxypyrazole is a known compound obtained by reacting l.3-dimethylpyrazolone with benzoyl chloride at heat in dioxane, pyridine, dimethylformamide or benzene in which quicklime or triethylamine is suspended. By this, 1
・A method of benzoylating the 4-position of 3-dimethylpyrazolone has been proposed, but the yield of the target compound is 70-75% even in dioxane in which quicklime is suspended.
Furthermore, an O-benzoyl compound is produced as a by-product.

(Himya Heterochiklicheskiv Saedeinienii, 1972.799) In addition, in the method described in the above-mentioned literature, benzoylation at the 4-position of pyrazolone is difficult to proceed with 2,4-dichlorobenzoic acid derivatives, and the above-mentioned general formula (I) The yield of the compound is less than 50%.

Furthermore, in the case of a benzoic acid derivative substituted with a methyl group at the ortho position, benzoylation at the 4-position of the pyrazolone ring hardly progresses.

The present inventors have conducted intensive research to obtain an industrially advantageous method for producing 4-benzoylpyrazole derivatives, and as a result, they have discovered an economical method for producing 4-benzoylpyrazole derivatives by using aluminum chloride as a catalyst for benzoylation at the 4-position of pyrazolone. We have completed the present invention by discovering a method that is significantly improved in terms of properties, ease of synthesis, etc.

According to the method of the present invention, the compound having the general formula (I) and its aluminum salt can be produced as follows.

That is, benzoic acid or its It can be obtained by reacting the reactive derivative in the presence of aluminum chloride.

In carrying out the method of the present invention, the reaction is carried out using the general formula (
n) is easily carried out by contacting the compound with the general formula (In) in the presence of aluminum chloride with or without a solvent.

The solvent to be used is not particularly limited as long as it has a boiling point of 30°C or higher and does not participate in this reaction, such as aromatic or halogenated hydrocarbons such as monochlorobenzene, dichloroethane, and tetrachloroethane. can give.

In either case, after addition of the aluminum chloride catalyst, the reaction system is heated or heated to 30°C or higher, preferably 60 to 120°C, thereby benzoylating the pyrazolone derivative having the general formula (II) at the 4-position. can be promoted.

The amount of aluminum chloride used is based on the formula (n) and (II
It is used in an amount equal to or more than 1 mole, preferably about 1.2 to 3 times the mole of the compound [).

Furthermore, the order in which the compounds of the formulas (I[) and (III) and the aluminum chloride catalyst are added is not particularly limited (usually, the compounds of the formulas (II) and (m) are mixed and the aluminum chloride catalyst By adding, compound (I) and its aluminum salt, which are the objects of the present invention, are produced in good yield.

Examples of reactive derivatives of benzoic acid having the general formula (III) include acid chlorides, acyl halides such as acid bromides, acid anhydrides, etc. However, in general, acid chlorides are preferred due to their reactivity and economic efficiency. I like it.

The amount of aluminum chloride catalyst added and the reaction temperature have a large effect on the amount of the target compound (I) and its aluminum salt produced.

Generally, by increasing the amount of aluminum chloride catalyst added, the yield of the target compound (I) and its aluminum salt increases.

When the amount of catalyst is large, for example, the formulas (n) and (III
), the desired compound (I) and its aluminum salt can be obtained in good yield even at a relatively low reaction temperature, for example, 30 to 80°C. Generate with .

On the other hand, when the reaction temperature is 80°C or higher, for example, ioo to 120°C or higher, it is possible to reduce the amount of catalyst to some extent.
Even when used in an amount of 1 to 1.5 times the mole of compound I), the target compound (I) and its aluminum salt can be produced in a good yield.

These reaction conditions can be selected arbitrarily.

After completion of the reaction, the target compound of the method of the present invention is collected from the reaction mixture by a conventional method.

For example, after the reaction is completed, the reaction mixture is washed with water and a dilute aqueous alkali solution, the organic layer is separated and dried, and the solvent is distilled off from the solution to obtain the aluminum salt of formula (I).

Alternatively, the compound of formula (I) can be freed by adding a mineral acid such as concentrated hydrochloric acid to water, treating in the same manner, separating the organic layer, drying with a suitable desiccant, and distilling off the solvent from the solution. obtained in the state.

The crude target compound can also be purified by conventional methods such as recrystallization.

In addition, the raw material compound of the formula (I[) is Berichte (Be
r,) 43.2106 (1910).

The general formula (I) obtained by the method of the present invention.

Representative compounds among the compounds having the following are described below.

■ 1,3-dimethyl-4-(2-chlorobenzoyl)
-5-hydroxypyrazole m, p, 154-155°C ■ 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole m, p, 165-1
66°C ■ 1,3-dimethyl-4-(2,4,5-trichlorobenzoyl)-5-human'c-xypyrazole m,p, 156-157°C ■ 1°3-dimethyl-4-(2-bromo benzoyl)
-5-hydroxypyrazole m, p, 154-156°C ■ 1,3-dimethyl-4-(2-methylbenzoyl)
-5-hydroxypyrazole m, p, 82-83°C ■ 1-ethyl-3-methyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole m, p, 176-177°C ■ l-allyl -3-Methyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole m, p, 161-163°C Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 1.3-dimethyl-4-(2.4-dichlorobenzoyl)-5-hydroquinpyrazole aluminum salt ■ l.3-dimethyl-5-pyrazolone ii, 2fI.

After mixing 20.9 i of 2,4-dichlorobenzoyl chloride in 100 rrLl of tetrachloroethane and heating under reflux for 30 minutes, 20.9 i of 2,4-dichlorobenzoyl chloride is added, followed by heating under reflux at about 100° C. for an additional 60 minutes.

Add 1001 rLl of cooled drained water and stir to remove the aqueous layer.

The organic layer was then washed with 401 rL of IN aqueous sodium hydroxide solution and dried over anhydrous sodium sulfate.

When the solid residue obtained by distilling off the solvent under reduced pressure is recrystallized from ligroin, the target compound 24 having a melting point of about 155°C is obtained.
．． 1' is obtained.

Yield 84.3% Elemental analysis value (%) Cl2H9N20
Calculated value as 2C12Al/3 C, 49,17; H43,09; N, 9.55
;C1,24,19 Actual value C049,22;H13,30;N, 9.1
8 ; C1, 23, 13 ■ 1,3-dimethyl-5-pyrazolone ii, 2y, 2
- Mix 4-dichlorobenzoyl chloride 2o and 9r in 100 ml of dichloroethane, heat under reflux for 30 minutes, and then distill off the solvent under reduced pressure.

Then add 16.05' of aluminum chloride and add about 120
Stir for 60 minutes at °C (stirring becomes difficult).

After the reaction is complete, add 100rrL of dichloroethane to the reaction mixture.
1 was gradually added dropwise, and the mixture was washed with 80 rIL of water.

After separating the organic layer and drying it with anhydrous sodium sulfate, the solution was
When the solvent was distilled off under reduced pressure, the target compound 23. IP is obtained.

Yield 79% Example 2 1,3-cyz-y-4-(2,4-dichlorobenzoyl)-5-hydroxypicizolto 3-dimethyl-5-pyrazolone 11.2P, 2,4-
After mixing 20.9 P of dichlorobenzoyl chloride in 100 ml of dichloroethane and heating under reflux for 60 minutes,
Stop heating and add aluminum chloride (anhydrous) 20. Add IP and heat under reflux for an additional 60 minutes (occurrence of HCI is observed).

After cooling, 100a of water was gradually added dropwise with stirring, and then 25 TLl of concentrated hydrochloric acid was added and the mixture was further heated and stirred for 2 hours.

After the reaction is completed, the aqueous layer is removed from the reaction mixture and the organic layer is concentrated to obtain crystals 214f of the target compound.

Yield 75% Elemental analysis value (%) Calculated value as Cl2H1IN304 C650,55; N13.53; N, 9.8
2; C1,24,88 Experimental value C050,85; H, 3,54; N, 9.8
1 ; C1,24,55 Example 3 1,3-dimethyl-4-(4-chlorobenzoyl)-5
-Hydroxypyrazole Aluminum salt In Example 2, 2,4-, dichlorobenzoyl chloride 20.9 p-chlorobenzoyl chloride 17.5 instead of P? When treated in the same manner as above, the melting point was 28.
The target compound 22.2P having a temperature of 2-284°C is obtained.

Yield 86% Elemental analysis value (%) Ct□H8°N202
Calculated value as CI Al/3 C155,72; H, 3,90; N, 10.8
3; C1,13,71' Experimental value C, 55,24; H, 3,87; N, 10.5
8; C1,14,05 Example 4 1,3-dimethyl-4-(2-chlorobenzoyl)-5
-Hydroxypyrazole Aluminum Salt When 0-chlorobenzoyl chloride 17.5P is used in place of 2,4-dichlorobenzoyl chloride 20.9f in Example 2 and treated in the same manner, the melting point is 295.
The target compound 21.71 with ~301'C is obtained.

Yield 84% Elemental analysis value (%) Cl2H1ON202
Calculated value as CI Al/3 C155,72; H, 3,90; N, 10.8
3; C1,13,71 Experimental value C055,44; H, 3,93; N, 10.4
2; C1,13,71 Example 5 1,3-dimethyl-4-(2-methylbenzoyl)-5
-Hydroxypyrazole 3-dimethylpyrazolone 1.12 f,0-toluoyl chloride 1.54? were mixed and heated in 20 ml of dichloroethane for 30 minutes, and then 2. O2
and heated under reflux for 60 minutes.

After cooling, 10 TL of water and 2.5 T/L of concentrated hydrochloric acid were added, and the mixture was further heated and stirred for 60 minutes.

The dichloroethane layer was separated and the solvent was distilled off under reduced pressure.
1.62 of a reddish-brown oil is obtained.

Acceptance rate: 69.6%. When a small amount of methanol is added and the mixture is allowed to stand, the desired compound is obtained as flame-brown crystals with a melting point of 82-83°C.

Elemental analysis value (%) C13N14 N202 Calculated value C167,81;H,6,28;N, 12.
17 Experimental value C, 67, 70; N06.03; N-12,
26

Claims (1)

[Claims] A pyrazolone derivative having the formula (wherein, R1 represents a lower alkyl group or a lower alkenyl group, and R2 represents a lower alkyl group) (wherein, X represents a halogen atom or a lower alkyl group) . n represents an integer from 1 to 3, and when n is 2 or 3,
may be the same or different from each other. 4-benzoylpyrazole having the formula (wherein R11R2, Process for producing derivatives and their aluminum salts.