IL28511A - 2-beta-halogenoallylthio-4,6-bis-amino-s-triazines and fungicidal compositions containing same - Google Patents

Description

New 2*^-halogenoallylt io-4» 6-amino-s- tfiazines and fungicidal compositions containing same NIPPON KAYAKU KABUSHIKl KAISHA C: 27063 IPPON AYAKU KABUSHIKI KAISHA Tokyo (Japan) NIP III New 2-p-halogenoallylthio- , 6-bis-amino-s-triazines and fungicidal compositions containing same The present invention relates to novel 2- ( β-halogeroallyl-thio) - , 6-bis-amino-s-triazines with excellent fungicidal activity, methods of controlling phytopathogenic fungi therewith, especially on cultivated plants such as rice and to fungicidal compositions for agricultural use, containing the novel triazines as active ingredients. 2-Allylthio-4 , 6-bis-amino-s-triazines and 2- (γ-dichlor-allylthio) -4 , 6-bis-amino-s-triazines are known as herbicides of considerable phytotoxicity .

Conforming to the present invention it has surprisingly been found that novel 2- ( -halogenoallylthio)-4 , 6-bis-amino-s-triazines of the general formula wherein and R2 independently of each other represent hydrogen or lower alkyl groups and X represents halogen, especially chlorine or bromine, possess an unexpected and excellent antifungal activity while being at the same time very well tolerated by cultivated plants„ The new compounds of formula I as well as compositions < culturally acceptable carriers are thus useful for inhibiting the growth of various kinds of phytopathogenic fungi that threaten cultivated plants, among them especially rice blast (Piricularia oryzae) which is known to infest rice plants.

When applied in amounts which effectively control rice blast, no noticeable damage to the rice plants could be observed,, Preferred amounts range from 500 to 750 grams per hectare.

The novel compounds are readily prepared by reacting a sodium mercaptotriazine of the general formula in which and have the same meaning as in formula I, with a dihalogeno-propene of the general formula X I X - CH2 - C = CH2 (III) in which X has the meaning as given above.

Details of how to make the compounds of formula I will seen from the following non-limitative examples. In these examples temperatures are given in degrees Centigrade.

Example 1 4 grams (g) of pulverized sodium hydroxide are added to 200 ml of dimethylformamide and 19.5 g of 2-mercapto- , 6-bis- (ethylamino)-s-triazine are then added thereto at 20° with stirring Stirring is continued for about 2 hours until a clear solution is obtained, the temperature of which has risen to about 35° . 11.2 g of 2 , 3-dichloro-propene are then added dropwise to the solution with stirring, the latter being continued for a further two hours while maintaining the temperature of the mixture at about 40°.

After cooling, the reaction mixture is poured into 500 ml of water, and the resulting mixture extracted with ethyl acetate. The extract is dried over sodium sulfate, the solvent evaporated and the residue recrystallized from iso-octane., 2- ( 2 · -chloro-allylthio)-4-,6-bis-(ethylamino)-s-triazine thus obtained has a melting point of 42 - 45°.

Other compounds according to the invention which are prepared by repeating example 1, but using in lieu of the s-triazine employed therein a correspondingly substituted amount of another triazine, and, where necessary, an equivalent amount of dibromo-propene in lieu of dichldro-propene , are the following: Example 2. 2- ( 2 * -chloro-allylthio)-4-isopropylamino-6-methylamino-s- triazine 3. 2- ( 2 ' -chloro-allylthio ) -4-isopropylamino-6-ethylamino-s- triazine 4. 2- (21 -chloro-allylthio) -4 , 6-bis-isopropylamino-- s-triazine . 2- ( 2 ' -chloro-allylthio ) -4 , 6-bis-amino- s-triazine 6. 2- ( 21 -bromo-allylthio) - , 6-bis-ethylamino-s-triazine 7. 2- ( 2 ' -bromo-allylthio ) ^-ethylamino-e-isopropylamino-s- triazine 8. 2-(2' -bromo-allylthio)-4,6-bis-isopropylamino-s-triazine - ' - - - - - - - r . 2-(2 ' -chloro-allylthio)-4-ethylamino-6-sec . -butylamino-s- triazine.

Fungus-growth inhibiting activities and control effects ■ of compounds of this invention are shown by the following experi- ments which are to serve only as illustration.

Experiment 1 / Minimum concentrations for inhibiting growth of rice blast (Piricularia oryzae) were determined by the following method.

Samples of 1 ml of acetone, each containing known concentrations of a different compound of this invention and 19 ml of- potato- agar media were poured into- a Petri dish of 9 cm in diameter, mixed well, and solidified. Each of the agar plates thus prepared was inoculated with a loopful of colloidal suspension of sporn and hypha of Piricularia oryzae.

After incubating for 7 days at 28°C, minimum concentrations for inhibiting growth were determined. The results are shown in Table I : Table I Compound of Minimum concentrations effectively Example No. inhibiting growth (mcg/ml) 1 12.5 2 12.5 3 6,25 4 25 6.25 6 3.125 7 ■ 3.125 8 3.125 9 6.25 The above results show that compounds according to this Experiment 2 Young rice plants (variety: Saitama mochi No. 10) were grown in a vat of 5 cm x 20 cm surface to the stage of 3 - 4 leaves, whereupon they where treated with compounds of this invention.

In a series of samples, each of which consisted of a wettable powder containing 10% of the active compound listed in the first column of the following table, each sample was diluted with water to a content of 500 ppm of active ingredient and admixed with a small quantity of distributing agent to afford a dispersible composition which was sprayed on a group of test plants. 24 hours after spraying, colloidal suspensions of coni-dium of blast incubated for 15 days in barley-rice straw media were sprayed on to the plants and also on to a lot of previously untreated control test plants. After inoculation, each plant was held in the incubator under the same conditions as in the pre ceding examples. Numbers of fungal spots were observed at 7 days after the inoculation. The results are shown in Table II below.

Table II Compound of ConcentraRatio of inNumber of Phytoto-Example No. tion ppm fected leaves fungal spots- xicity per leaf 1 500 16 0.26 none 2 Π 32 0.86 3 10 0.20 4 25 0.48 28 1.03 6 30 0.92 7 26 1.05 8 34 0.72 Compound of Concentre- Ratio of in- Number of Phytoto- Example No. tion ppm fected leaves fungal spots xicity per leaf 9 500 42 1.26 none Untreated lot - 84 5.83 — number of infected leaves ratio of infected leaves = x 100 total number of leaves When the compounds according to the invention are formulated for use, suitable carriers or diluent for admixture therewith are for example the following: clay, kaolin, talcum powder, diatomaceous earth, silica, calcium carbonate, sawdust, etc and/or water, benzene, alcohol, acetone, xylene, methylnaphthalene , cyclohexanone , dimethyl form-amide, dimethyl sulfoxide, vegetable oils, animal oils, fatty acids, esters of fatty acids and various kinds of surfactants; adjuvants which are conventional in the preparation of agricul-tural chemicals, for example, stickers, emulsifying ^agents , wetting agents, binding or adhesive agents may also be ^included for increasing the desired control effect. Moreover, the compounds according to the invention may be used, if desired, in admixture with compatible fungicides, insecticides, nematocides, herbicides and/or plant growth regulators, soil conditioners or fertilisers.

An amount of about 500 to 750 g of active ingredient per hectare of planted area, especially of rice fields is recommended. When dressing rice seeds, the concentration of active ingredient in the dressing should preferably be in the range of about 100 to 150 ppm.

The following non-limitative examples illustrate the composition aspect of the invention further; part's are given therein by weight.

Mixing 3 parts of 2- (2 * -chloro-allylthio)-4 , 6-bis-ethyl-amino-s-triazine with 50 parts of talc and 47 parts of clay by weight, and crushing affords a dust composition suitable for applicationo Example II 60 Parts of 2-(2 ' -chloro-allylthio)-4-isopropylamino-6-methyl-amino-s-triazine were mixed with 17 parts of diatomaceous earth, one part of alkyl naphthalene sulphonate, and 2 parts of lignin sulphonate by weight to obtain a wettable powder which is readily dispersed and suspended in water for fungicidal use.

Example III Parts of 2- ( 21 -bromo-allylthio ) -4-isopropylamino-6-ethylamino-s-triazine were solved into 33 parts of methylnaph-thalene, and admixed , with 17 parts of polymer of allylphenol ethyleneoxide to afford an emulsifiable solution which is readily dispersible in water, whereby aqueous spray compositions are obtained which are highly effective for the control of blast.

Example IV 3 Parts of 2- ( 2 ' -bromo-allylthio ) -4 , 6-bis-isopropylamino-s-triazine were dissolved in 12 parts of xylene, and · the solution was mixed with 60 parts of starch and 25 parts of polyvinyl pyrrolidone to formulate tablets. '■'-"-· The tablets of. this example can be dissolved -in water to afford aqueous spray compositions which are used for the control of blast in the field, or aqueous solutions which are used as soaking agents for seeds, inhibiting the .growth of blast . 28511/2

Claims (9)

1. A compound of the formula wherein and R2 Independently of each other represent hydrogen or lower alky! groups, and X represents chlorine or bromine.

2. A compound as defined in Claim 1, which is 2-( '-chloro~allylthlo)-4-lsopropylamino~6-methylainino-s-triazine.

3* A compound as defined in Claim 1, which is 2- (2 · -chloro-allylthio)-4,6-bis-eth lamino-s-triazine.

4. A compound as defined in Claim 1, which is 2- (2 · -bromo-allylthio)-4-ethylamino-6-isopropylamino-s-triazine«

5. A compound as defined in Claim 1, which is 2-( ·-bromo-allylthio)-4.6-bis-isopropylamino-s-triazine .

6. A fungicidal composition comprising a compound as defined in Claim 1 in sufficient amount to inhibit fungal growth, and an agriculturally acceptable carrier for said compound .

7. A method of controlling fungal growth comprising applying to a locus susceptible to growth of fungi a fungal growth-inhibiting amount of a compound as defined in Claim 1. - 9 - 28511/2

8.. A method of controlling growth of blast on rice plants comprising applying to the said plants or to rice seeds a blast growth-inhibiting amount of a compound as defined in Claim 1.

9. A method as defined in Claim 8, wherein the amount of said compound ranges from about 500 to 750 grams per hectare. PC/rb