JPH0439465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to 4,5-ethylenedioxy-2-nitrophenol and a method for producing the same. The compound of the present invention is an intermediate for the active ingredient of a plant disease control agent. That is, O-ethyl O-4,5-ethylenedioxy-2-nitrophenyl N- which can be produced by reacting the compound of the present invention with, for example, O-ethyl N-sec-butyl thionolamide chloride. sec-Butyl phosphoroamide thioate is an active ingredient of a plant disease control agent, and has a control effect against plant diseases such as downy mildew and late blight. The inventors have discovered that 4,5-ethylenedioxy-2
- As a result of studying the method for producing nitrophenol, it was found that 4,5-ethylenedioxy-2-nitrophenol can be produced in high yield and with high purity by nitrating and hydrolyzing 3,4-ethylenedioxyphenyl acetate. It has been discovered that phenol can be produced. Next, the method for producing the compound of the present invention will be described in detail. Nitration of 3,4-ethylenedioxyphenyl acetate is carried out using, for example, a mixed acid of sulfuric acid and nitric acid, a mixed acid of acetic acid and nitric acid, fuming nitric acid, or nitric acid in a halogenated hydrocarbon solvent, usually at 0 to 10°C, at 12 The reaction takes place within hours. After the reaction is completed, acetic acid 4,5
-ethylenedioxy-2-nitrophenyl is obtained. The hydrolysis of 4,5-ethylenedioxy-2-nitrophenyl acetate obtained as described above is as follows:
It is carried out in the presence of an alkali or acid catalyst. For hydrolysis with an alkali catalyst, for example, an alkaline aqueous solution such as sodium hydroxide is added to an alcoholic solution of 4,5-ethylenedioxy-2-nitrophenyl acetate, and the mixture is reacted at 40 to 60°C for 1 to 5 hours. Alternatively, 4,5-ethylenedioxy-2-nitrophenyl acetate is added to an alcoholate solution and the mixture is heated under reflux for usually 1 to 7 hours. Acid-catalyzed hydrolysis can be carried out using, for example, acetic acid 4,5
Hydrochloric acid or sulfuric acid is added as a catalyst to an alcoholic solution of -diethylenedioxy-2-nitrophenyl, and the reaction is usually carried out at 60 to 80°C for 4 to 8 hours. After the reaction is complete, the reaction mixture is neutralized, and if necessary, the solvent is distilled off, the resulting crystals are collected, washed with water, and then dried to obtain 4,5-ethylenedioxy-2-nitrophenol. 3,4-ethylenedioxyphenyl acetate, which is a raw material compound, is produced by reacting 3,4-ethylenedioxyphenyl methyl ketone with a peracid such as peracetic acid or metachloroperbenzoic acid, or by reacting 3,4-ethylenedioxyphenyl methyl ketone with a peracid such as peracetic acid or metachloroperbenzoic acid. It can be produced by reacting dioxyphenol with an acetylating agent such as acetic anhydride or acetyl chloride. In addition, 3,4-ethylenedioxyphenylmethylketone and 3,4-ethylenedioxyphenol are described in J.Chem.Soc., 1957 3445
It can be produced by the method described in 3447. Example 3,4-ethylenedioxyphenyl acetate (5.93
g, 30.5 mmol) in 15 ml of acetic acid and heated at 4-7°C.
A mixed solution of 2.0 ml of nitric acid (d=1.50) and 3.0 ml of acetic acid was added dropwise over 30 minutes while stirring. After the dropwise addition was completed, the temperature was returned to room temperature, the reaction solution was poured into ice water, the crystals were collected, washed with water, and acetic acid 4,5-ethylenedioxy-
2-nitrophenyl was obtained (mp 105-106°C).
After heating and dissolving this in 80ml of methanol, 50ml
Drop 4.0ml of % sodium hydroxide aqueous solution and add 40~
The mixture was kept at 60°C and stirred for 1 hour. The reaction solution was cooled with ice water, neutralized by adding 10% hydrochloric acid, and methanol was distilled off. The precipitated crystals were collected, washed with water, and dried to obtain 4,5-ethylenedioxyphenyl-2-nitrophenol. Obtained 4.50g. mp 173-174℃ Yield 74.8% Reference Example 1 3,4-ethylenedioxyphenylmethylketone (6.00g, 33.7mmol) and m-chloroperbenzoic acid (9.0g, 52mmol) were dissolved in 200ml of methylene chloride.
The mixture was stirred at room temperature for 3 hours. After the reaction was completed, the mixture was washed with an aqueous sodium thiosulfate solution and an aqueous sodium bicarbonate solution, dried over magnesium sulfate, and methylene chloride was distilled off. 5.93 g of 3,4-ethylenedioxyphenyl acetate was obtained. Yield 90.7% Reference Example 2 4,5-ethylenedioxy-2-nitrophenol (1.97 g, 10 mmol) was dissolved in 100 ml of acetonitrile.
Add anhydrous potassium carbonate powder (1.40g) and cuprous chloride (10mg), and keep at 40-50℃ for 30 minutes.
Stir for 1 minute. To this was added O-ethyl N-sec-butylthionolamide chloride (2.2 g,
10 mmol) was added dropwise over 40 minutes, and the mixture was further stirred and refluxed for 3 hours. After cooling, inorganic salts were separated, acetonitrile was distilled off, the residue was dissolved in toluene, and washed with dilute hydrochloric acid, water, dilute aqueous alkali solution, and then water.
It was dried with anhydrous magnesium sulfate. Toluene was distilled off, 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-butylphosphoroamide thioate. mp 59-61℃ Yield 62.0% Reference test example Grape mildew control 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, they were grown in a greenhouse at 23°C for 10 days, and their control efficacy was investigated. The control efficacy is determined 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", 10%. ``4'' if approved to a certain degree, ``3'' if approved by 30%, ``2'' if approved by 50%,
If it is observed in about 70%, it is scored as "1", and if it is more than 70% and there is no difference from the disease onset state when no compound is tested, it is scored as "0". , 3, 4, and 5. In addition, chlorothalonil and aluminum tri(ethylphosphonate) were used for comparison. The results are shown in Table 1. 【table】

Claims (1)

[Claims] 1 4,5-ethylenedioxy-2-nitrophenol. 2. A method for producing 4,5-ethylenedioxy-2-nitrophenol, which comprises nitrating 3,4-ethylenedioxyphenyl acetate and then hydrolyzing it.