JPS59216855A - 2-halo-4-amino-6-substituted phenol and its preparation - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I (X is halogen; Y is lower alkoxy, or lower alkoxymethyl). EXAMPLE:2-Chloro-4-amino-6-methoxymethylphenol. USE:An intermediate for synthesizing an active ingredient for agricultural and horticultural fungicide. A compound shown by the formula I is reacted with isopropyl chloroformate, and with cyanomethyl chloride to give an isopropyl 3-halo- 4-cyanomethoxy-5-substituted phenylcarbamate shown by the formula II having strong fungicidal action on plants fungi showing resistance to benzimidazole and thiaphanate fungicides. PREPARATION:A 2-halo-4-nitro-6-substituted phenol shown by the formula III is reduced to give a compound shown by the formula I . The reduction is carried out by reduction with sodium hydroxide, reduction with iron powder, or catalytic reduction, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a 2-halo-4-amino- The present invention relates to a 6-substituted phenol (hereinafter referred to as the compound of the present invention) and a method for producing the same.

The compound of the present invention is an intermediate for producing the active ingredient of a fungicide for horse horticulture. That is, the compound of the present invention has the general formula (II) which can be produced by reacting it with isopropyl chloroformate and then reacting it with cyanomethyl chloride [wherein X and V are the same as above]. ] The isopropyl 3-halo 4-cyanomethoxy-5-substituted phenyl carbamate has an extremely strong bactericidal effect against plant pathogens that are resistant to benzimidazole/thiophanate fungicides, which have become a problem in recent years. Furthermore, when used in combination with these fungicides, it is possible to sufficiently control plant diseases in many fields. (See reference side) The compound of the present invention has the general formula [...] [In the formula, X and Y are the same as above. ] is obtained by the method of reducing the 2-halo-4-nitro-6-substituted phenol.

Examples of the reduction method include reduction using hydrogen sulfide, reduction using iron powder, and catalytic reduction.

In reduction with sodium hydrosulfide, the general formula ((II')
A 2-halo-4-nitro-6-substituted phenol represented by the formula is mixed with at least an equivalent amount of sodium bisulfide relative to the phenol in a solvent such as water, methanol, ethanol, impropatol, benzene, toluene, etc., or a mixture thereof. 15 in the temperature range from 40°C to the reflux temperature of the solvent used.
The compound of the present invention can be produced in good yield by reacting for about 10 minutes to about 10 hours.

In reduction with iron powder, 2 expressed by the general formula (Ill”l)
- Halo 4-nitro-6-substituted phenol and electrolyzed iron or reduced iron in a solvent such as water, methanol, ethanol,
Using a mineral acid such as hydrochloric acid or sulfuric acid or an organic acid such as acetic acid,
The compound of the present invention can be produced in good yield by reacting for about 15 minutes to 10 hours at a temperature ranging from 0° C. to the reflux temperature of the solvent used.

In the catalytic reduction, the 2-halo-4-nitro-6-substituted phenol represented by the general formula (III) is reacted with methanol, ethanol, or inpropanol.

am, ethyl acetate, benzene, toluene, etc., using platinum dioxide, palladium-carbon, Raney nickel, etc. as a catalyst, and using hydrogen gas at normal pressure to 1005-atm, in a temperature range from room temperature to 100C. By reacting for 12 hours, the compound of the present invention can be produced with good yield.

In addition, 2-halo 4 represented by the general formula ([11)] of the raw material
-Nitro-6-fil! Phenol is J, Org, Ch
Em, 27 218 (1962).

Next, examples and reference examples will be shown.

Example 1 Preparation of 2-chloro-4-amino-6-methoxymethylphenol.

2.18 f of 2-chloro-4-nitro-6-medoxymethylphenol was dissolved in 50 ml of ethyl acetate, and 0.20 f of platinum dioxide was added thereto. Next, catalytic reduction was carried out using hydrogen at 1 atm. After stopping the absorption of hydrogen, the catalyst was separated and the r liquid was concentrated under reduced pressure. The obtained solid was recrystallized from toluene to obtain 2-chloro-4-amino-6-methoxymethylphenol 6-1,54r. (Yield 82.1%,) Melting point 50~
52°C Example 2 In the same manner as in Example 1, 2-chloro-4-nitro-6-
From 2.182 liters of ethoxyphenol, 1.70 r of 2-chloro-4-amino-6-nitoxyphenol was obtained. (Yield 90.6%) MR δ (CDCe1): 6.10 (d, IH), 5
．． 9Fl (d.

l fI), 8.92 ((+, 2H), Bog 5 (
broad.

211), 1.84 (t, 8l-1) Reference Example Cucumber gray mold control effect 90w/A plastic pot was filled with sandy loam and cucumbers (variety: Sagami Hanshiro) were sown. This was cultivated in a greenhouse for 8 days, and 10 g of a water diluted solution of the test compound in the form of an emulsion or a wettable powder was sprayed on the stems and leaves of cucumber seedlings in which cotyledons had developed.

After air-drying, a microflora section (diameter 5 enz) of cucumber gray mold fungus (Botrytim7-c (nerea)), which is drug-resistant or drug-susceptible, was attached to the seedlings.
was inoculated by pasting it on the leaf surface. The mice were left under humid conditions at 20° C. for 3 days to develop the disease, and then the disease state was observed and observed.

The disease severity was calculated by the following method.

That is, 0.0.5.1.2 depending on the appearance of lesions on the investigated leaves.
The disease was classified into four indexes, and the severity of the disease was calculated using the following formula.

(Infection Index) (Infection Status) O No bacterial flora or lesions observed on the leaf surface.

0.5 Bacterial flora or lesions are observed on the leaf surface in less than 5% of the leaf area.

1. Bacterial flora or lesions are observed on the leaf surface in less than 20% of the leaf area.

2. Bacterial flora or lesions are observed on the leaf surface in less than 50% of the leaf area.

4 Bacterial flora or lesions are observed on the leaf surface over 50% of the leaf area.

Next, the control value was calculated from the following formula.

As a result, as shown in Table 1, isopropyl N-(8-chloro-4-cyanomethoxy-5-methoxymethylphenyl)carbamate showed an excellent control effect when inoculated with drug-resistant bacteria; The agents benomyl, thiophanate methyl and thiabendazole showed excellent control effects when inoculated with drug-susceptible bacteria.

Table 1

Claims (2)

[Claims] (1) General formula [In the formula, X represents a halogen atom, and Y represents a lower alkoxy group or a lower alkoxymethyl group. ] A 2-halo 4-amino-6-substituted phenol represented by: (2) General formula [wherein, X represents a halogen atom, and Y represents a lower alkoxy group or a lower alkoxymethyl group]. [In the formula, X and Y are the same as above. ] A method for producing a 2-halo 4-amino-6-substituted phenol.