NO146563B - HERBICIDE PREPARATIONS CONTAINING A QUARTERLY BIPYRIDYLIUM SALT AND A TRIAZOLO-PYRIMIDINE - Google Patents

Description

This invention relates to herbicidal preparations containing

a herbicidal quaternary bipyridylium salt as active ingredient.

Over the years, a number of different pesticides have been developed

for agricultural purposes to combat fungi, harmful insects and weeds. Although these substances are necessarily toxic to certain forms of life, when used with care and in accordance with official regulations, they will not represent any danger to human life. However, despite efforts to encourage those who come into contact with pesticides to adopt safe handling methods, cases of pesticide misuse do occur. A particularly unsafe practice when it comes to liquid pesticides is that a small amount of the concentrated pesticide is transferred to a household container such as can be a bottle for beverages, for later use at home. The risk associated with this practice is, of course, that a child or a careless adult who comes across the bottle may swallow the contents with potentially serious consequences.

We have now found it possible to reduce the likelihood of serious consequences from such accidental ingestion by inducing vomiting. In some cases, this can result in the rapid removal of the pesticide preparation from the stomach and digestive tract before lethal amounts of the pesticide can be assimilated by the body.

We have found that the addition of a known triazolo[1,5-a]-pyrimidine derivative of formula (I) as set forth below to a herbicidal quaternary bipyridylium salt in a herbicidal preparation produces a preparation which, if swallowed, tends to to induce vomiting and thereby expulsion of the preparation.

According to the invention, a herbicidal preparation with a reduced health risk is thus provided, containing a salt of a herbicidal quaternary bipyridylium cation and an s-triazolo[1,5-a]-pyrimidine derivative with the formula:

where R is hydrogen, a C..-alkyl radical or a COOEt radical, 2 3

R is a C^^-alkyl radical or an allyl radical, and R is a C^^^-alkyl radical, and addition salts thereof. The s-triazolo[1,5-a]-pyrimidine ring structure is numbered as shown below:

Special derivatives of 5-oxo-4,5-dihydro-s-triazolo-[1/5-a]pyrimidine for use according to the invention are: 6-methyl-4-n-propyl-2-n-propylaitu. no-,

2-amino-6-methyl-4-allyl-,

2-amino-4,6-di-n-propyl-, and

The 2-ethoxycarbonylamino-6-methyl-4-n-propyl derivs.

A particularly suitable triazolo-pyrimidine for use in the preparations according to the invention is 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II ).

The herbicidal quaternary bipyridylium salts for use in the preparations according to the invention are those which have the following formulas: or

where R and R"*", which are the same or different, mean alkyl radicals with from 1 to 4 carbon atoms which are optionally substituted

with hydroxyl, halogen, carboxyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, carbamoyl or N-substituted carbamoyl;

[X]n means an anion, and n is an integer from 1 to 4.

Particularly preferred herbicidal quaternary bipyridylium salts

are those listed below: 1,1'-dimethyl-4,4<1->bipyridylium-di(methylsulfate) (paraquat-dimethosulfate)

1,1'-ethylene-2,2,-bipyridylium dibromide (diquat dibromide)

1,1'-dimethyl-4,4'-bipyridylium dichloride (paraquat dichloride)

1,1'-di-2-hydroxyethyl-4,4'-bipyridylium dichloride 1-(2-hydroxyethyl-1'-methyl)-4,4'-bipyridylium dichloride 1,1'-di-carbamoylmethyl-4 ,4'-bipyridylium dichloride 1,1'-bis-N,N-dimethylcarbamoylmethyl-4,4'-bipyridylium dichloride 1,1'-dimethyl-4,4<1->bipyridylium sulfate (paraquat sulfate)

1,1'-bis-N,N-diethylcarbamoylmethyl-4,4'-bipyridylium dichloride 1,1'-diacetonyl-4,4'-bipyridylium dichloride

1,1'-diethoxycarbonylmethyl-4,4'-bipyridylium dibromide

The names in parentheses after some of the compounds in the above list are the accepted trivial names for these compounds. Thus "paraquat" is the trivial name for the 1,1'-dimethyl-4,4'-bipyridylium cation. Paraquat is a particularly preferred bipyridylium cation for use in the preparations according to the invention. A particularly preferred anion [X]<n>~ is the chloride anion for practical and economic reasons, but any anion leading to a suitable water-soluble salt may optionally be used. The herbicidal effect is due exclusively to the cation, and the concentration of a herbicidal bipyridylium salt preparation is therefore often stated as the cation alone. The amount of herbicidal quaternary bipyridylium salt present in the preparations according to the invention is usually from 1.0 to 99.9% by weight.

The preparations according to the invention may contain a carrier or diluent, and may be solid substances, e.g. granules, or liquids, e.g. aqueous solutions.

According to a preferred embodiment of the invention, a concentrated herbicide preparation is provided containing an aqueous solution of a salt of a quaternary bipyridylium cation herbicide and a triazolo-pyrimidine as defined above. Preferably, the herbicidal quaternary bipyridylium cation is paraquat.

The amount of herbicide quaternary bipyridylium cation which

is present in the aqueous solution, is preferably from 50 to 400 g per litres.

Preferably, the preparation also contains a surfactant.

Surfactants can be cationic, non-ionic or anionic in nature. In general, cationic and non-ionic surfactants are preferred over anionic surfactants for use in the preparations according to the invention, since the latter may react in an undesirable manner with the quaternary bipyridylium salt in the preparations. Examples of non-ionic surfactants for use in the preparations according to the invention include condensation products of ethylene oxide with alkylphenols such as octylphenol, nonylphenol and octylcresol. Other nonionic agents are the partial esters derived from long-chain fatty acids and hexitol anhydrides, e.g. sorbitan monolaurate; condensation products of said partial esters with ethylene oxide; and lecithins. Examples of cationic surfactants include quaternary salts and condensates of ethylene oxide with amines, e.g. the drugs sold under the trade names "Ethomeen", "Ethoduomeen", "Duoquad" and "Arquad".

Particularly preferred surfactants are the combinations of surfactants described in British patent 998,264 for use in preparations containing herbicidal quaternary bipyridylium salts.

The preparation of the triazolo-pyrimidines (I) is described

in British Patent 1,234,635, to which reference should be made.

The vomiting-inducing properties of the preparation are determined in particular by the amount of triazolo-pyrimidine it contains. In determining the most appropriate amounts of triazolo-pyrimidine for use in a preparation, consideration must be given to the effectiveness of the triazolo-pyrimidine in relation to the toxicity of the herbicide. The amount of triazolo-pyrimidine introduced is preferably such that any amount of the preparation containing a potentially lethal dose of the herbicide will contain sufficient of the triazolo-pyrimidine to induce vomiting. Of course, neither lethal doses nor vomiting-inducing doses can be measured directly in humans, and they can only be calculated on the basis of animal experiments.

Preparations according to the invention preferably contain from 0.1 to 5 parts by weight of the triazolo-pyrimidine (e.g. the triazolo-pyrimidine II) per 100 parts herbicide quaternary bipyridylium cation (eg paraquat). Suitably, the amount of the triazolo-pyrimidine (eg, the triazolopyrimidine II) used is 0.25 to 2.0 parts per 100 parts herbicide quaternary bipyridylium cation (eg paraquat).

Concentrated aqueous preparations according to the invention are corrosive. They must be handled with care to avoid splashing in the eyes or on the skin, and they must not be allowed to come into contact with corrodible metals before dilution.

The preparations according to the invention can also contain colored dye or pigment compounds to give them a characteristic and distinguishing colour. Examples of such compounds are "Monastral Blue BNV Paste" and "Lissamine Turquoise VN 150".

The preparations according to the invention can also contain a smelly agent. Examples of such malodorous agents are: alkylpyridines as described in British Patent 1,406,881; n-valeric acid; and tetrahydrothiophene.

Optionally, the triazolo-pyrimidines (I) can be introduced into thixotropic preparations of herbicidal quaternary salts. In particular, the triazolo-pyrimidines (I) can be introduced into the preparations containing herbicidal quaternary bipyridylium salts described in our British patent 1,395,502. These preparations comprise an aqueous solution of a herbicidal quaternary bipyridylium salt containing a gelling agent, e.g. finely divided silicic acid, or a combination of the xanthan gum sold under the trade name "Kelzan" with sodium metaborate. Xanthan gum is a complex polysaccharide.

The preparations according to the invention may also contain a herbicide other than a quaternary bipyridylium salt herbicide as defined above. Examples of such herbicides are: Amides (e.g. N,N-diallylchloroacetamide, 3,4-dichloropropionanilide, N-(3-chloro-4-methylphenyl)-2-methylpentamide).

Carbamates (eg isopropyl-N-phenylcarbamate, isopropyl-N-(3-chlorophenyl)-carbamate, 4-chloro-2-but-2-ynyl-N-(3-chlorophenyl)-carbamate, 2-chloroallyl- N,N-diethyl dithiocarbamate). Ureas/anilides (e.g. N,N'-di-(2,2,2-trichloro-1-hydroxy-ethyl)urea, 3,4-dichloroacetanilide, o-chloroisobutyranilide, α-bromo-3,4- dichloroacetanilide, 3,4-dichloroformanilide, 2-acetamido-3-chlorotoluene).

Diazines (e.g. 3,4,5,6-tetrahydro-3,5-dimethyl-2-thio-2H-1,3,5-thiadiazine, 5-bromo-3-isopropyl-6-methyluracil, 5- amino-4-chloro-2-phenyl-3-pyridazone, 1,2,3,6-tetrahydro-3,6-dioxopyridazine).

Triazines (e.g. 2-chloro-4,6-bisethylamino-1,3,5-triazine, 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine, 2-chloro-4, 6-bisisopropylamino-1,3,5-triazine, 4-ethylamino-6-isopropylamino-2-methoxy-1,3,5-triazine, 4,6-bisisopropylamino-2-methoxy-1,3,5-triazine) .

Introduction of the triazolo-pyrimidine (I) into the preparations

according to the invention has no harmful effect on the herbicidal activity of the preparations. The following examples shall serve to further illustrate the invention.

Example 1

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) in aqueous solution.

Paraquat concentrate is a solution of paraquat dichloride containing 25 to 30% by weight of 1,1<1->dimethyl-4,4'-bipyridylium cation. The amount used was chosen to give a preparation containing 20% w/v paraquat cation. The preparation was prepared by mixing the ingredients together.

Example 2

This example illustrates a preparation according to the invention which contains the triazolo-pyrimidine (II) in aqueous solution. The preparation contains the following ingredients.

"Lissapol" NX is a trademark for a surfactant containing a condensate of from 7 to 8 moles of ethylene oxide with 1 mole of p-nonylphenol.

DS 4392 is a code number for a surfactant containing a mixture of amines derived from soybean fatty acids condensed with approximately 15 mole parts of ethylene oxide.

"Silcolapse" is a trademark for an antifoam agent containing a silicone derivative.

The preparation described above was prepared by mixing the ingredients together.

Example 3

This example illustrates a preparation according to the invention which contains a gel-forming agent in addition to the triazolo-pyrimidine (II). The preparation contains the following ingredients

The preparation described above was prepared by stirring the ingredients together and was sufficiently liquid after preparation that it could be poured into containers. On standing for 15 to 20 minutes, the preparation formed a gel and could not be poured unless vigorously shaken.

Example 4

This example illustrates a dry, free-flowing granular formulation that is both stable on storage and readily reconstitution to an aqueous solution for use as a douche.

A solution was prepared with the following composition, where the indicated percentages are by weight.

310 g of the above described solution was then added in a thin stream to 690 g of dried magnesium sulfate contained in the container of a "HOBART" CE. 100 dough mixers. After the resulting product was dry, it was passed through a granulating machine and finally agitated in a 30 mesh per sieve. 2.5 linear cm to remove dust. The resulting granules had a size of at least 0.9 mm and had a dissolution rate of 150 seconds.

Example 5

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) and a smelly agent in aqueous solution.

The preparation described above was prepared by stirring the ingredients together.

Example 6

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) in a thickened, colored, aqueous solution.

"Synperonic" and "Nansa" are trademarks. "Synperonic" 2

is a condensation product of a mixture of 67% C, 3 Q( 3 33% C^-aliphatic alcohols with two equivalents of ethylene oxide. "Synperonic" 16 is a condensation product of a mixture of 67% C, 3 °<? 33% C^ -aliphatic alcohols with 16 equivalents of ethylene oxide. "Nansa" 1106 is sodium dodecyl-(mainly C, 2 linear chain)-benzenesulfonate. Monastral BNVS paste is a dispersion containing 15% w/v copper phthalocyanine pigment in water. Pyridine base is a mixture consisting mainly of alkylpyridines.

Example 7

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) in aqueous solution.

Diquat ion is 1,1'-ethylene-2,2'-bipyridylium cation.

The preparation described above was prepared by stirring the ingredients together and had a pH of 6.5 in 0.3.

Example 8

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) in aqueous solution.

Morphamquat ion is 1,1'-bis(3,5-dimethylmorpholinocarbonylmethyl)-4,4'-bipyridylium ion. The preparation described above was prepared by stirring the ingredients together.

Example 9

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine (II) in aqueous solution. The preparation described above was prepared by stirring the ingredients together.

"Tween" is a trademark. "Tween" 20 is a condensation product of 1 mol of sorbitan monolaurate with 20 mol of ethylene oxide.

Example 10

This example illustrates a preparation according to the invention containing 2-n-propylamino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine in aqueous solution.

Example 11

This example illustrates a preparation according to the invention which contains 2-amino-5-oxo-4,6-di-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine in aqueous solution.

Example 12

This example illustrates a preparation according to the invention which contains 2-ethoxycarbonylamino-6-methyl-5-oxo-4-n-propyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine in aqueous solution.

Example 13

This example illustrates a preparation according to the invention which contains 2-amino-6-methyl-5-oxo-4-allyl-4,5-dihydro-s-triazolo[1,5-a]pyrimidine in aqueous solution.

Claims (2)

1. Herbicidal preparation with a reduced health hazard, characterized in that it contains a salt of a herbicidal quaternary bipyridylium cation and an s-triazolo[1,5-a]-pyrimidine with the formula: where R<1> is hydrogen, a C 1-4 alkyl radical or a COOEt 3 radical; R<2> is a C 1-6 alkyl radical or an allyl radical; and R is a C^_^ alkyl radical; and the salt of the herbicidal cation is a compound of the formula: or where R and r, which are the same or different, mean alkyl radicals with from 1 to 4 carbon atoms which are optionally substituted with hydroxyl, halogen, carboxyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, carbamoyl or N-substituted carbamoyl; [X]n means an anion, and n is an integer from 1 to 4 2. Preparation as stated in claim 1, characterized in that the salt of a herbicide bipyridylium cation is a compound of the formula: where [X]n means an anion, and n is an integer from 1 to 3, and the s-triazolo[1,5-a]pyrimidine is 2-amino-6-methyl-5-oxo-4-n-propyl -4,5-dihydro-s-triazolo[1,5-a]pyrimidine.