DD258165A1 - ALGICIDES AND HERBICIDAL AGENTS CONTAINING 2-HETARYL-CHINOXALINE - Google Patents

Abstract

The invention relates to algicidal and herbicidal agents with a broad spectrum of activity. As active ingredient they contain 2-hetaryl-quinoxalines, where hetaryl (un) substituted pyridyl, pyrazolyl, thiazolyl, benzo & b! Furyl, benzo bienyl, benzoxazolyl or benzimidazolyl.

Description

Examples of the substances according to the invention Het (Formula I) molar mass -2- F. 258 165 Table 1: R Gross (g-mor ¹ ) (X) No. Pyrid-2-yl formula 207.2 116-118 H Pyrid-3-yl C ₁₃ H ₉ N ₃ 207.2 113.5 to 114.5 1 H Pyrid-4-yl C ₁₃ H ₉ N ₃ 207.2 119-120 2 H Pyrazol-3-yl C ₁₃ H ₉ N ₃ 197.2 183-184 3 H 2-methyl-thiazol-4-yl C ₁₁ H ₈ N ₄ 227.3 118.5 to 120 4 H 2,4-dimethyl-thiazol-5-yl C ₁₂ H ₉ N ₃ S 241.3 97 5 H 2-phenyl-4-methyl-thiazol-5-yl C ₁₃ H ₁₁ N ₃ S 303.4 179-181 6 H Benzo [b] fur-2-yl C ₁₈ H ₁₃ N ₃ S 246.3 174-175 7 H 3-methyl-benzo [b] thien-2-yl , C ₁₆ H ₁₀ N ₂ O 276.4 118-119 8th H Benzo [b] fur-2-yl C ₁₇ H ₁₂ N ₂ S 260.3 142 to 143.5 9 CH ₃ Benzoxazol-2-yl C ₁₇ H ₁₂ N ₂ O 261.3 181-182 10 CH ₃ Benzimidazol-2-yl C ₁₆ H ₁₁ N ₃ O 260.3 191-192 11 CH ₃ C ₁₆ H ₁₂ N ₄ 12

embodiments

example 1

Synthesis of 2-methyl-3- (3-methyl-benzo [b] thien-2-yl) quinoxaline

To solve 11.1 TI. Selenium dioxide of 75Tl. Dioxane and 3Tl. Water is added to the solution of 19Tl. 2-acetyl-3-methylbenzo [b] thiophene (Z. Chem. 10 [1970] 462) in 50 μl. Dioxane added and boiled under reflux for 3 hours. The reaction mixture is filtered hot to remove the precipitated selenium, with the solution of 10.8Tl. o-phenylenediamine in 30 μl. Dioxane added and heated for an additional hour to boiling. The solution is concentrated in vacuo, allowed to cool, filtered from the crystallized product and crystallized from propanol, acetone, ethyl acetate or cyclohexane to. Yield 73% of theory, melting point 118-119 ° C.

Example 2

Testing the algicidal activity

The effectiveness of the compounds according to the invention was tested by determination of active quantities in standardized chlorella tests and by comparison of these active quantities with corresponding data of quinoxaline derivatives known as herbicides, such as 2-phenyl, 2-fur-2-yl and 2-thien-2-one. yl-quinoxaline (CA 87 [1977] P 195546J; 88 [1978]

P 16549Oq; 91 [1979] P 193335y). >

The principle of the selected autotrophic or heterotrophic growth tests, which makes it possible to effectively characterize algicidal and phytotoxically active compounds by influencing complex growth and developmental parameters of the unicellular green alga Chlorella vulgaris var. Vulgaris, strain BÖHM and BORNS 1972/1, consists in the 6 ^(15l- hour parallel confrontation of synchronous Chlorella constant cell density suspensions (approximately 7.5 x 10 ⁶ autos pores / ml) with concentration series of the respective active ingredient under species-specific optimized growth conditions (37.5 ° C, 101% air with 2% by volume CO ₂ / h, 20000 Ix / light expenses) for the autotrophic and test variant (37.5 ⁰ C, 101 air with 2 vol .-% CO ₂ / h and 0.1% glucose as the organic carbon source) for the heterotrophic test variant.

The resulting biological effect W, expressed as percent growth inhibition, is via absorbance measurements at 680nm and 750nm, respectively, or pH measurements according to the equation

Ek-E ₀

pH _K -

where E ₀ (pH) is the standardized initial absorbance (initial pH), Ew (pHw) and E _K (pH _K ) the extinctions or pH values of treated or parallel-exposed control suspensions after 6 ⁽¹⁵⁾ hours Test duration. From the dose-dependency of the relative percentage growth inhibitions, the negative decadic logarithms of the effector parameters defined as activity parameters, which cause a 50% inhibition of autotrophic or heterotrophic algal growth (pc ₅₀ ) and absorbance measurements at 680 nm or 750 nm or via pH measurements the algal suspensions are accessible, can be determined by graphic interpolation. The results are summarized in Table 2.

It can be seen from Table 2 that when compared to 2-phenylquinoxaline (15) whose herbicidal activity is known, the 2-hetarylcinoxalines 6,8-11,13,14 are the same in the assay for algicidal activity in the autotrophic Chlorella test show greater effects. Furthermore, it is found that choline axines possessing a benzo [b] fur-2-yl or benzo [b] thien-2-yl radical in the 2-position as heteroaromatic substituents have particularly high activity; Thus, for example, the compounds 8 and 9 compared to the herbicide used as 4,6-dinitro-o-cresol (16) an approximately ten-fold higher effect in the Chlorella test used

A comparison of the effective quantities pc ₅ o, the extinction measurements at 680 nm and 750 nm as well as pH measurements

Table 2: Activity parameter pc ₅₀ ¹ 'for the effect of compounds 1 to 12 according to the invention and of comparative effectors 13 to 16 in standardized chlorella tests

No. R H et pc ₅ o ²¹ ₃ ) - 1 H Pyrid-2-yl 4.08 - 2 H Pyrid-3-yl 3.86 - 3 H Pyrid-4-yl 4.15 - 4 H Pyrazol-3-yl 3.91 - 5 H 2-methyl-thiazol-4-yl 4.29 - 6 H 2,4-pimethyl-thiazol-5-yl 4.91 - 7 H 2-phenyl-4-methyl-thiazol-5-yl 4.82 5.64 8th H Benzo [b] fur-2-yl 6.09 5.43 9 H 3-methyl-benzo [b] thien-2-yl 6.31 5.41 10 CH ₃ Benzo [b] fur-2-yl 5.72 - 11 CH ₃ Benzoxazol-2-yl 4.93 - 12 CH ₃ Benzimidazol-2-yl 4.56 4.83 13 H Fur-2-yl ⁴ⁱ 6.01 - 14 H Thien-2-yl ⁴⁾ 5.30 - 15 H Phenyl ⁴¹ 4.95 4.91 16 DNOC (4,6-dinitro-o-cresol) ⁴ ' 5.11

D PC ₅₀ = -Ig (ED ₅₀ ); [ED ₅₀ ] = mol · 1 ^-1

2) Action parameters for autotrophic growth inhibition, determined from extinction measurements at 680 nm

3) Action parameters for the inhibition of heterotrophic growth, determined from extinction measurements at 680 nm

4) herbicidal activity known

were determined for the autotrophic test variant in a single operation, showed the dose specific the optical properties at 680 nm are more affected than the cell growth at 750 nm. At the same time, the nitrate conversion is more influenced than the cell growth at 750 nm. These effects, the Comparison to the 2-phenyl-quinoxaline in the compounds of the invention occur significantly more, have in comparison to other commercial agents on a priority Tangierung the nitrate conversion, which opens up selective applications of the drugs.

Example 3:

Testing the herbicidal activity

In pot experiments, the herbicidal activity of the compounds according to the invention was tested in pre- and post-emergence applications using a medium sorption capacity bottom with a water capacity of 60%. The compounds were applied as a 20% spray powder formulation in 1000 l water per ha by means of an injector syringe immediately after the sowing of the weeds (VA) and stocks growing for 14 days (NA). The following key was used to assess the herbicidal potency:

Boniturnote Schad strength Weed stocking in% 1 destroyed 0 2 CJL 3 15 4 30 5 50 6 70 7 85 8th 95 9 100 unharmed

Representative of the compounds according to the invention, the test results are shown in Table 3 using the specified Boniturskala.

Table 3: Herbicidal action of the compounds according to the invention when using 10 kg of active substance per ha

No. of the VA: I Il III Test plants ¹¹ V Vl VII links N / A: 7 4 ISJ IV 4 CJL 6 gemäßTab. 1 VA: 1 1 1 4 1 2 3 1 N / A: 9 9 9 1 9 9 9 VA: 1 1 1 7 1 3 2 2 N / A: 9 9 9 1 9 9 9 VA: 1 1 1 9 1 6 7 3 N / A: 7 7 5 Ί 8th 8th 8th VA: 6 1 1 6 1 CJL 9 6 N / A: 3 3 CJL 1 3 6 8th 3 2 1 4 1 4 3 11 1

-4- ZuV praise

1) Test plants: I = Medicagosativa Il = Lactucasativa III = Lycopersicum escul. IV = Betavulgaris V = Sinapisalba Vl = Lolium multiflorum VII = Avenasativa

Claims (2)

Algicides and herbicidal agents, characterized in that they in addition to conventional excipients and carriers as the active ingredient 2-Hetaryl-quinoxalines of the general formula Het in which R = H or CH ₃ and Het represents an unsubstituted or a radical substituted by one or more alkyl and / or aryl radicals of a heteroaromatic radical, the heteroaromatic radical itself being pyrid-2-yl, pyrid-3-yl, Pyrid-4-yl, pyrazol-3-yl, thiazol-4-yl, thiazol-5-yl, benzo [b] fur-2-yl, benzo [b] thien-2-yl, benzoxazol-2-yl or Benzimidazol-2-yl can be. Field of application of the invention The invention relates to novel agents for controlling algae and undesired plant growth Characteristic of the known technical solutions It is known that hetaryl-substituted quinoxalines have already been mentioned as biologically active substances in the literature. For thienylquinoxaline salts, a digitalis-like effect could be observed (HeIv chim Acta35 [1952] 2301). Antimicrobial action possess furyl, thienyl or pyridyl-quinoxaline-1,4-dioxides (Swiss Appl. 2729/70 of 25.2.70). Some substituted furylquinoxalines have an antibacterial effect (Chim.Farm.Z. 2 [1986] 14, Gidroliz Proizvod., 1978, 17). Furyl and thienylquinoxalines have been protected as herbicides applicable to rice crops (Japan Kokai 1977,36927 dated 21.6.76, C. A.88 [1978] P 16549Oq). About biological, especially herbicidal activities of other quinoxalines with heteroaromatic substituents is not yet known. Object of the invention The aim of the invention is to develop new algicidal and herbicidal compositions which have a broad spectrum of activity against algae and weeds. Explanation of the essence of the invention This object is achieved in accordance with the invention in that the algicidal and herbicidal compositions contain, in addition to customary excipients and carriers, as the active ingredient 2-hetaryl-quinoxalines of the general formula (I) Het in which R = H or CH ₃ and Het represents an unsubstituted or a radical substituted by one or more alkyl and / or aryl radicals of a heteroaromatic radical, the heteroaromatic radical itself being pyrid-2-yl, pyrid-3-yl, Pyrid-4-yl, pyrazol-3-yl, thiazol-4-yl, thiazol-5-yl, benzo [b] fur-2-yl, benzo [b] thien-2-yl, benzoxazol-2-yl or Benzimidazol-2-yl can be. The preparation of the active compounds according to the invention is carried out in a manner known per se (Gazz, Chim., Italian 89 [1959] 1598; Bull Soc., Chim., France, 1961, 933; Z. Chem. 22 [1982] 300, Pharmazie 38 [1983]. 829; 40 [1985] 384), in particular by oxidation, bromination or isonitrosation of acyl heteroaromatics in the side chain and cyclization of the reaction products with o-phenylenediamine, as illustrated by Example 1. Some of the 2-hetaryl-quinoxalines (Formula I) obtained in this way are listed in Table 1. The active compounds according to the invention are used as algicides in 10 ^"4 to 10 ~ ⁶ molar amounts are used. The use as herbicidal agents is expediently carried out in the usual herbicides preparation or application forms such as solutions, emulsions, suspensions, with the addition of liquid and / or solid carriers or diluents, usually with the addition of surface-active substances, can be diluted with water for application The application rates are expediently 1 to 1 of active substance per hectare.The application forms depend on the intended use and in each case have a fine distribution The preparation of the preparations is carried out in a manner known per se by mixing and grinding processes.