JPH0439466B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the general formula [] [In the formula, X represents a halogen atom. ] It is related with the manufacturing method of 4,5-ethylenedioxy-2-nitrophenol by reacting 2-halo-4,5-ethylenedioxynitrobenzene shown by these in a solvent in the presence of an alkali metal hydroxide. 4,5-ethylenedioxy-2-nitrophenol is an intermediate of the active ingredient of a plant disease control agent. That is, 4,5-ethylenedioxy-2-
O-ethyl O- which can be produced by reacting nitrophenol with O-ethyl N-sec-butyl thiophosphoamide chloride
4,5-ethylenedioxy-2-nitrophenyl N-sec-butyl phosphoroamide thioate is an active ingredient of a plant disease control agent, and has a control effect on plant diseases such as downy mildew and late blight. The present inventors obtained 4,5-ethylenedioxy-2-
As a result of studying the method for producing nitrophenol, we found that 2-halo 4, represented by the general formula [] above,
5-ethylenedioxynitrobenzene is heated to 70 to 200°C for about 1 to 24 hours in a solvent in the presence of 2 equivalents or more of alkali metal hydroxide to produce 4,5-ethylenedioxynitrobenzene. -2-
It has been discovered that nitrophenol can be produced. In the above production method, examples of solvents include dioxane, tetrahydrofuran, ethers such as ethylene glycol dimethyl ether, nitriles such as acetonitrile and isobutyronitrile, N,
Examples include acid amides such as N-dimethylformamide and N,N-dimethylacetamide, and sulfuric acid compounds such as dimethyl sulfoxide and sulfolane. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. After the reaction is completed, usual post-treatments are carried out, and if necessary, purification is carried out by chromatography, recrystallization, etc. 2- represented by the general formula [] which is a raw material compound
Halo-4,5-ethylenedioxynitrobenzene has the general formula [] [In the formula, X represents the same meaning as above, and Y represents a halogen atom. ] β-(2,4-dihalo-5-nitrophenoxy)ethanol represented by the above is mixed with acetonitrile N,N-dimethylformamide, in the presence of the alkali metal hydroxide or fluoride such as potassium fluoride or cesium fluoride It can be produced by heating in a solvent such as dimethyl sulfoxide or sulfolane. Next, examples will be shown. Example 1 500 mg of 2-chloro-4,5-ethylenedioxynitrobenzene was dissolved in 5 ml of dimethyl sulfoxide, heated to 100°C, and 400 mg of potassium hydroxide powder was dissolved.
was added and kept at 120-140°C for 1 hour. After cooling, the mixture was poured into 50 ml of ice water, extracted twice with 50 ml of ethyl acetate, and the extract was washed with water and dried over magnesium sulfate. Ethyl acetate was distilled off, and the residue was purified by silica gel column chromatography to obtain 290 mg of 4,5-ethylenedioxy-2-nitrophenol. mp170-173°C Example 2 2.6 g of 2-fluoro-4,5-ethylenedioxynitrobenzene was dissolved in 15 ml of sulfolane, 2.2 g of potassium hydroxide powder was added, and the mixture was kept at 80-100°C for 3 hours. After cooling, pour into 100ml of ice water, Example 1
4,5-ethylenedioxy-
1.38 g of 2-nitrophenol was obtained. mp170~173℃ Next, for reference, O-ethyl O-4,5-ethylenedioxy-2-nitrophenyl N-sec
-Production examples and test examples of butyl phosphoroamide thioate are shown. Reference production example 4,5-ethylenedioxy-2-nitrophenol (1.97 g, 10 mmol) was dissolved in acetonitrile.
Dissolve in 100ml and add anhydrous potassium carbonate (1.40
g) and cuprous chloride (10 mg) at 40-50℃.
Stirred for 30 minutes. Then, O-ethyl N-sec-butylthionolamide chloride (2.2 g, 10 mmol) was added dropwise over 40 minutes, followed by stirring and refluxing for 3 hours. After separating the inorganic salts, acetonitrile was distilled off under reduced pressure. The residue was dissolved in toluene, washed successively with a dilute aqueous acid solution, a dilute aqueous alkali solution, and water, and dried over anhydrous magnesium sulfate. Toluene was distilled off under reduced pressure, and the residue was further purified by silica gel column chromatography to obtain 2.33 g of O-ethyl O-4,5-ethylenedioxy-2-nitrophenyl N-sec-butyl phosphoramidothioate. mp59-61℃ Reference test example Grape mildew control effect test (therapeutic effect) Plastic pots were filled with sandy loam, grapes (neomuscatus seeds) were sown, and grown in a greenhouse for 50 days. A spore suspension of grape downy mildew was inoculated by spraying onto young grape seedlings in which the 4th to 5th true leaves had developed. After inoculation, the plants were grown for one day at 25° C. under humid conditions, and an emulsion of the test compound was diluted with water to a predetermined concentration and sprayed on the foliage to ensure sufficient adhesion to the leaf surface. After spraying, the plants were grown in a greenhouse at 23°C for 10 days, and their control efficacy was investigated. The pesticidal efficacy is evaluated by visually observing the disease state of the test plants at the time of the survey, that is, the degree of bacterial flora and lesions on leaves, stems, etc., and if no bacterial flora or lesions are observed, it is rated "5".
If about 10% is observed, it is "4", if about 30% is observed, it is "3", if about 50% is observed, it is "2", if about 70% is observed, it is "1", and if the compound is not tested if it is more than that. If there is no difference from the disease onset state, it is evaluated as "0" and evaluated on a 6-level scale from 0 to 5.
Displayed as 1, 2, 3, 4, 5. In addition, chlorothalonil and aluminum tris(ethylphosphonate) were used as comparison controls. The results are shown in Table 2. [Table]

Claims (1)

[Claims] 1. General formula [In the formula, X represents a halogen atom. ] 2-halo-4,5-ethylenedioxynitrobenzene represented by is reacted in a solvent in the presence of an alkali metal hydroxide.
A method for producing ethylenedioxy-2-nitrophenol.