JPS6041672A - Production of 4,5-ethylenedioxy-2-nitrophenol - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as an intermediate of an active component of plant blight controlling agent, easily, by heating beta-(2,4-dihalo-5-nitrophenoxy)ethanol in the presence of an alkali metal hydroxide. CONSTITUTION:The objective compound is produced by heating the compound of formula I (X and Y are same or different halogen) at 70-200 deg.C in a solvent such as dioxane, tetrahydrofuran, etc. in the presence of an alkali metal hydroxide. The reaction is carried out in the absence or presence of a catalyst such as copper powder, cuprous chloride, etc. The starting compound of formula I can be prepared e.g. by reacting 2,4-dihalo-5-nitrophenol of formula II with 1-5 equivalent of ethylene halohydrin in a solvent such as acetonitrile, in the presence of a base at 60-150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compound of the general formula [I] [wherein X and Y are the same or different and represent a halogen atom]. ] 4゜5-ethylenedioxy-2 by heating β-(2,4-dihalo-5-nitrophenoxy)ethanol shown in a solvent in the presence of an alkali metal hydroxide.
-Relating to a method for producing ditrophenol.

4.5-Ethylenedioxy-2-nitrophenol is an intermediate of the active ingredient of a plant disease control agent. That is, 0-ethyl 0-4.5-ethylene, which can be produced by reacting 4,5-ethylenedioxy-2-ditrophenol with, for example, 0-ethyl N-5ee-butyl thionolamide chloride. Dioxy-2-nitrophenyl N-sea-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 present inventors investigated the method for producing 4,5-ethylenedioxy-2-ditrophenol, and found that β-(2゜4-dihalo-5-nitrophenoxy) represented by the above general formula [I] ) It is rumored that ethanol is dissolved in a solvent in the presence or absence of a catalyst. - usually for 1 to 2 hours
It has been found that 4,5-ethylenedioxy-2-ditrophenol can be produced by heating from 70°C to 200°C for 4 hours.

Examples of the m-medium include ethers such as dioxane, tetrahydrofuran, and ethylene glycol dimethyl ether;
Nitriles such as acetonitrile and isobutyronitrile, N
, N-dimethylformamide, acid amides such as N,N-dimethylacetamide, and sulfur compounds such as dimethyl sulfoxide and sulfolane.

Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide.

Examples of the catalyst include copper powder and cupric chloride.

After the reaction is completed, usual post-treatments are carried out, and if necessary, purification is carried out by chromatography, recrystallization, etc.

β-(2,4
-dihalo-5-nitrophenoxy)ethanol, for example, has the general formula CU] [wherein X and Y represent the same meanings as above. ] 2,4-dihalo-5-nitrophenol and 1
~5 equivalents of ethylene halohydrin and acetonitrile,
In the presence of an inorganic base such as sodium hydroxide or potassium carbonate in a solvent such as N,N-dimethylformamide or dimethyl sulfoxide, 1 to 2% at 60 to 150°C.
It can be produced by reacting for 4 hours.

Next, examples will be shown.

Example 1 2.0 g of β-(2,4-dichloro-5-ditrophenoxy)ethanol was dissolved in dimethyl sulfoxide, and 0.0 g of β-(2,4-dichloro-5-ditrophenoxy)ethanol was dissolved in dimethyl sulfoxide. Add lf and heat to 100”C,
Add 1.5y of sodium hydroxide powder to 180~1
Keep at 50℃ for 1 hour. After cooling, the ethyl acetate was poured into 100 ml of ice water and ethyl acetate was distilled off under reduced pressure.

\) Purified by column chromatography to obtain 0.67 g of 4.5-ethylenedioxynitronitrophenol.
child.

m, p, 170-178°C Example 2 β-(2-chloro-4-fluoro-5-nitrophenoxy)ethano, -l 2, Of dimethyl sulfoxide],
OTn! , and 1.40 g of potassium hydroxide powder was added thereto, heated, and kept at 120 to 130° C. for 3 hours. After cooling, pour into 100 tni of ice water and add 100 tni of ethyl acetate.
The product was purified by 2 silica gel chromatography to obtain 0.72f7i of 4,5-ethylenedioxy-2-ditrophenol.

m, p, 170-178℃ Next, reference H construction examples and reference test examples are shown.

Reference production example 4.5-ethylenedioxy-2-nitrophenol (1
, 97f, 10 tnmol) in acetonitrile 10
Dissolve in 0 ml of anhydrous potassium carbonate +7/A powder (1,4
Add 0F and cuprous chloride (10q) to 40-50
The mixture was stirred for 80 minutes while maintaining the temperature at °C. To this, 0-ethyl N −
5ee-butylthionolinic acid amide chloride (2.2g
, 10n110n1 were added dropwise over 40 minutes, and the mixture was further stirred and refluxed for 8 hours. After cooling, the inorganic salts are removed in a furnace, the acetonitrile is distilled off, the residue is dissolved in toluene, washed with dilute hydrochloric acid, water, a dilute aqueous alkaline solution, then water, and dried over anhydrous magnesium sulfate. Toluene was distilled off and further purified by silica gel column chromatography to obtain 〇-ethyl 0
-4.5-ethylenedioxy-2-nitrophenyl N
-5ec-butyl posphoramidothioate 2.88
I got a 9.

m, p, 59-61℃ Yield 62.0% Reference test example Grape vine disease control test (therapeutic effect) Fill plastic bots with sandy loam and add grapes (neomuscat seeds) to WIW
The cells were grown in a greenhouse for 50 days. A spore suspension of grapevine and disease bacteria is applied to young grape seedlings that have developed their 4th to 5th true leaves.
1 locus was inoculated. After inoculation, the test compound was grown for 1 day at 25°C under humid conditions, and the test compound was made into an emulsion and diluted with water to a predetermined concentration.
It was sprayed on the foliage so that it adhered sufficiently to the leaf surface. After spraying, the plants were grown in a greenhouse at 28°C for 10 days, and their control efficacy was investigated.

In addition, the control efficacy is determined by the disease state of the test plants at the time of the survey, that is, the bacterial flora on leaves, stems, etc., and the degree of lesions. Observe, if no bacterial flora or lesions are observed, score "5", if about 10% are observed, score "4", if about 80% are observed, score 1'-8J,
If it is observed in about 50%, it is ``2'', if it is observed in about 70%, it is ``l'', and if it is more than that and there is no difference from the disease onset state when no compound is tested, it is graded as rOJ, and it is graded into 6 grades from 0 to 5. It was evaluated and expressed as 0.1.2.3.4.5.

In addition, chlorothalonil (ethylphosphonate) aluminum was used as a comparison. The results are shown in Table 1.

Claims (1)

[Claims] General formula [wherein X and Y are the same or different and represent a halogen atom]. ] 4,5-ethylenedioxy-2-nitrophenoxy, which is characterized by heating β-(2,4-dihalo-5-nitrophenoxy)ethanol shown in a solvent in the presence of an alkali metal hydroxide. Method for producing phenol.