JPH061774A - Production of 3@(3754/24)2h)-pyridazinone derivative - Google Patents

Abstract

PURPOSE:To obtain a derivative useful as an intermediate, etc., for insect pest controlling agents, etc., in good efficiency and high yield by reacting a specific benzyl hydrazine derivative with mucochloric acid in an inactive solvent. CONSTITUTION:A benzyl hydrazine derivative of formula I [X is halogen, lower haloalkyl, lower haloalkoxy or lower alkyl; (n) is 0-2] or its mineral salt is made to react with mucochloric acid in a solvent such as benzene inactive to the reaction to provide the objective derivative.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a general formula (1) described below, which is useful as an intermediate of an active ingredient compound for agricultural chemicals, especially pest control agents.

[0002]

[Chemical 3]

[In the formula, X represents a halogen atom, a lower haloalkyl group, a lower haloalkoxy group or a lower alkyl group, and n represents 0, 1 or 2. ] 3 (2
H) -pyridazinone derivative

[0004]

2. Description of the Related Art 3 (2) represented by the following general formula (1)
H) -pyridazinone derivative is a known compound, and the synthetic method thereof is Chemical Pharmaceutical Bulletin [Chem. Pharm. Bull. ], 18
Vol. 1, No. 1, pp. 147-156 (1970), 4,5-dichloro-3 (2H) -pyridazinone and benzyl chloride were added to N, N- in the presence of potassium carbonate.
A method of reacting in dimethylformamide (DMF) at room temperature is described. However, this method yields 5
It is 4%, and it cannot be said that the method for industrially producing a large amount of the compound represented by the general formula (1) is satisfactory because the yield is low.

The methods for synthesizing compounds in which the 2-position of the 3 (2H) -pyridazinone ring is substituted with a phenyl group, a methyl group or a t-butyl group are described in Journals.
Of the American Chemical Society [J. A
m. Chem. Soc. ], 75, 1909 (19
53), Journal of Chemical Society [J. Chem. Soc. ], P. 2191 (1948)
And JP-A-61-10561, a method of reacting phenylhydrazine, methylhydrazine and t-butylhydrazine with mucochloric acid is described.

However, there is no description about a method for producing a compound represented by the general formula (1) by reacting benzylhydrazine or a substituted benzylhydrazine or a mineral acid salt thereof with mucochloric acid, The industrial production method of the compound represented by the general formula (1) has been an unsolved problem.

[0007]

The compound represented by the general formula (1) described below is useful as an intermediate of an active ingredient compound of a pesticide, especially an insect pest control agent, and is industrially used in a large amount in a high yield. Manufacturing is the subject of the present invention.

[0008]

Means for Solving the Problems As a result of various studies on practically advantageous synthesis methods of the compound represented by the general formula (1), the present inventors have found that the general formula (2)

[0009]

[Chemical 4]

[In the formula, X and n have the same meanings as described above. ] The benzylhydrazine derivative represented by or the mineral acid salt thereof is reacted with mucochloric acid in a solvent inert to the reaction to give 3 (2H) represented by the general formula (1).
The present invention was completed by finding that a -pyridazinone derivative can be obtained in high yield.

The reaction studied by the present inventors is shown as a reaction formula as follows.

[0012]

[Chemical 5]

According to the reaction represented by the above reaction formula, the benzylhydrazine derivative represented by the general formula (2) as a raw material may be itself or a mineral acid salt. In the case of the mineral acid salt, an aqueous base solution (for example, NaOH aqueous solution, It can be used for the reaction as it is after being treated with a KOH aqueous solution).

Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene, alcohols such as methanol, ethanol and propanol, amides such as dimethylformamide and dimethylacetamide, diethyl ether, tetrahydrofuran and 1,4-. Ethers such as dioxane, halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride and 1,2-dichloroethane, organic acids such as formic acid, acetic acid and propionic acid, acetonitrile, dimethyl sulfoxide, mineral acid aqueous solution, water, etc. Is mentioned. In some cases, these solvents may be mixed and used. When using a solvent other than an organic acid or an aqueous mineral acid solution, it may be effective to add an acid to the solvent. At this time, examples of the acid include formic acid, acetic acid, propionic acid, p-toluenesulfonic acid, benzoic acid, hydrochloric acid and sulfuric acid.

The reaction temperature may be in the range of 0 ° C. to the boiling point of the solvent used, and more preferably 10 ° C. to 110 ° C. The molar ratio of the compound represented by the general formula (2) to mucochloric acid can be set arbitrarily, but more preferably 0.8 to 1.5 relative to mucochloric acid. The method of the present invention has an advantage over the conventional method in that a large amount of the target product can be obtained with a high yield and an easy operation.

[0016]

EXAMPLES Next, the method of the present invention will be described with reference to specific production examples. However, the present invention is not limited to these production examples.

Production Example 1 To 15 g of benzylhydrazine dihydrochloride, 40 ml of water and 10 ml of concentrated hydrochloric acid were added and heated to 90 ° C. After 13 g of mucochloric acid was added with vigorous stirring, the mixture was heated to the reflux temperature and reacted for 2 hours. After cooling, the resulting oily substance was extracted with benzene, washed with an aqueous solution of sodium hydroxide, washed with water, dried over anhydrous sodium sulfate, and then benzene was distilled off under reduced pressure to obtain the target compound 2-benzyl-4,5-dichloro. −
17.4 g of 3 (2H) -pyridazinone (yield 88.5
%) Was obtained.

Production Example 2 1 g of benzylhydrazine hydrochloride was suspended in 10 ml of toluene, and 0.27 g of sodium hydroxide and 0.6 m of water were suspended.
1 was added and stirred for 30 minutes. Then mucochloric acid 1.0
7 g was added, and the mixture was stirred at 70 ° C. for 4 hours. After the reaction was completed, water was added to separate the toluene solution, and the solution was washed with water and toluene was distilled off under reduced pressure to give 2-benzyl-4,5-dichloro-
1.4 g of 3 (2H) -pyridazinone (yield 85.3%)
Got

[0019]

The method of the present invention significantly improves the yield of the target compound as compared with the prior art.

Claims (1)

[Claims] 1. A compound represented by the general formula (1): [In the formula, X represents a halogen atom, a lower haloalkyl group, a lower haloalkoxy group or a lower alkyl group, and n represents 0, 1 or 2. ] In producing a 3 (2H) -pyridazinone derivative represented by the following general formula (2): [In formula, X and n represent the same meaning as the above. ] The manufacturing method characterized by reacting the benzylhydrazine derivative or its mineral acid salt represented by these with mucochloric acid in the solvent inactive to reaction.