HU199395B - Process for producing aniline derivatives suitable for protecting woods against wood destroying fungi and insects - Google Patents

Abstract

Wood preservative fungicide and insecticide aniline derivs., are prepd. by redn. with nascent hydrogen at 50-90 deg.C of nitro-polychloro-benzene and sepn. of the resulting polychloro-aniline from the reaction mixt.

Description

The present invention relates to a process for the preparation of polychlorinated aniline for the protection of wood materials against wood fungi and insects.

This active ingredient is excellent for protecting various types of wood, such as pre-wet, semi-dry, unprocessed and processed wood.

Many materials have already been used for this purpose with less success; among them were inorganic compounds such as fluorine, arsenic, mercury and copper, as well as organic compounds, most of which were phenol, naphthalene and tar. Reference is made in the relevant literature to summaries describing processes and useful products for the effective protection of wood. Here we refer to eg. G. Langendorf: Handbuch für den Holzschutz (Leipzig, 1961) and Gyarmati-Igméndy-Pagony: Wood Conservation (Budapest, 1964).

Literature data and practical use have shown that the above-mentioned compounds have several disadvantages, such as those which are released from the substance to be protected within a short period of time, e.g. already on finished wood and finally tar products are dangerous because of their well-known carcinogenic effect.

Our aim was to produce a fungicide and insecticide that eliminates the disadvantages of the past and at the same time its price is as low as possible. This latter condition can be achieved if the starting material is cheap and the production technology is neither complicated nor energy intensive.

In our experiments, we wanted to further modify the nitro derivative of polychlorobenzene, a byproduct of chlorination of benzene, which in itself proved to be effective against wood fungi and wood-destroying insects, because in our previous experiments there were indications that these The compounds are expected to exhibit better fungicidal and insecticidal activity than the starting material.

In the course of our further work, we have attempted to reduce these nitro compounds primarily by assuming that the resulting aniline derivative will be highly effective.

Accordingly, attempts have been made to reduce nitro-polychlorobenzene to the corresponding amino derivative. The reaction was carried out in aqueous medium with iron powder and concentrated hydrochloric acid. Considering that the nitro-substituted compound of polychlorobenzene contains several components, it took a lot of work to set up the best experimental conditions. The preferred technology was the reduction with nascent hydrogen at temperatures below 100 ° C. The reaction time was varied from 6 to 14 hours. The polychloro30-aniline formed was crystalline and was isolated from the mixture by filtration.

Examining the resulting product, we found that the insecticidal activity showed a significant increase in the initial potency as well as the compound, and compared the product obtained with the pentachlorophenol used. The results of the measurement by the enzymatic decontamination method (C.E. Mendoza Pest. Rev. 43, 105 (1973)) are shown in the table below.

Table 1

Compound Pentaklúr phenol 100% Hitra-poly chlorobenzene 110% Polychlorinated aniline 130% The resultant product has been tested in practice for both surface treatment and saturation applications and has been found to be applied at a maximum of 10 g / nm on the surface and 15 kg / m ^{3 in} the saturation process to achieve adequate protection. In the process of the present invention, nitro-polychlorobenzene from Table 2, formed during the chlorination of the benzene and treated as a waste material, was reduced in aqueous solution with gQ iron powder and concentrated hydrochloric acid with stirring at 50-90 ° C for 6-14 hours. has been redesigned.

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Table 2

Composition of starting material

number Compound Percentage First xylene 0.2-0.6 Second Dichlorobenzene; 0.4 Third Trichlorobenzene 3.0 to 7.0 4th 1,2,4,5-tetrachlorobenzene 5.0-8.0 5th 1,2,3,4-tetrachlorobenzene 12.0 to 16.0 6th Pentachlorobenzene 12.0 to 16.0 7th Hexachlorobenzene max. 1.0 8th Nitro-dichlorobenzene 1.1-1.3 9- Nitro-trichlorobenzene 9.0 to 18.0 10th Nitro-1,2,4,5-tetrachlorobenzene 8.0 to 12.0 11th Faith-1,2,3,4-tetrachlorobenzene 30.0 to 35.0 12th Nitro pentaklórbenzol 5.0-8.0

After cooling, the resulting crystalline material was filtered off and its composition, as shown in Table 3, was determined.

Table 3

Composition of the active substance

number Compound Percentage First xylene 0.2-0.6 Second Dichlorobenzene; 0.4 Third Trichlorobenzene 3.0 to 7.0 4th 1,2,4,5-tetrachlorobenzene 5.0-8.0 5th 1,2,3,4-tetrachlorobenzene 12.0 to 16.0 6th Pentachlorobenzene 12.0 to 16.0 7th Hexachlorobenzene max. 1.0

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3. Continue Table

number Compound Percentage 8th Nitro-dichlorobenzene 0 9th Nitro-trichlorobenzene 3.0 to 5.0 10th Nitro-1,2,4,5-tetrachlorobenzene 1.0-2.0 11th Nitro-l, 2,3,4-tetrachlorobenzene 5.0-7.0 12th Nitro-pe nachlorobenzene 0.5-3.0 13th Dichloroaniline 1.5-2.5 14th Trichloroaniline 10.0 to 15.0 15th 1,2,4,5-tetrachloro-aniline 9.0 to 11.0 16th 1,2,3,4-tetrachloroaniline 20.0 to 25.0 17th Pentachlorophenol-aniline 4.0-6.0

The material produced by the process has the advantage that it is more effective than known products, its toxicity is significantly lower, its starting material is the utilization of a waste in two steps, thus reducing environmental pollution, and the fact that the production technology is simple and does not require investment.

The following examples illustrate our process in detail, without limiting our claims therein.

EXAMPLE 1 Nitro-polychlorobenzene (containing 74% of the polychlorobenzene nitro derivative) was mixed with 100 ml of water, 20 g of reduced iron powder was added with further stirring, and it was heated to 80 ° C and 300 ml of cc over 1 hour. hydrochloric acid was added to the reaction mixture. After a further 8 hours at this temperature, the reaction mixture was cooled and the crystalline product formed was filtered off.

Yield: 8.3 g of polychloroaniline. M.p. 57-103 ° C.

Example 2

To 10 g of nitro-polychlorobenzene in 100 ml of water (60% nitro derivative)

3q 15 g of reduced iron powder were stirred and 150 ml cc was added dropwise over 2 hours. hydrochloric acid at 60 ° C. Stirring was continued at this temperature for a further 12 hours. After completion of the reduction, the reaction mixture was cooled and the polychloroaniline formed was filtered off. Yield: 8.1 g. M.p. 65-112 ° C.

Claims (2)

CLAIMS 1. A process for the preparation of an aniline derivative suitable for protecting wood from wood fungi and insects, comprising treating nitro-polychlorobenzene with hydrogen at about ⁴⁵ DEG C. for one to four hours at a temperature of 50-90 ° C. while maintaining After 6-14 hours, the reaction mixture was cooled and the resulting polychloroaniline was recovered by filtration. Process according to claim 1, characterized in that the nascent hydrogen is reduced with iron powder and concentrated hydrochloric acid. 55.