NO823837L - THIAZOLO- AND (1,3) THIAZINO (2,3-C) (1,2,4) TRIAZINONES WITH SELECTIVE HERBICIDE EFFECT - Google Patents

Description

The present invention relates to thiazolo- and [1,3]-thiazino-[2,3-c] [1,2,4]^triazinones with selective herbicidal action, as well as methods for the production of these compounds.

Triazinones with herbicidal action are already known (BE-PS 69 70 83; BE-PS 79 98 54). However, these herbicides do not solve the problem of a good herbicidal effect against problem weeds and at the same time good compatibility with several main agricultural crops that are in rotation.

One task of the present invention is to develop a means that can be used against difficult-to-control weeds in several main agricultural crops without damaging them.

According to the invention, this task is solved with thiazolo- and [1,3]-thiazino-[2,3-] [1,2,41-triazones of general formula*. ; in which denotes a C-^-Cg alkyl residue which is optionally interrupted by one or more oxygen or sulfur atoms, an alkyl carboxylic acid or ester residue, a C^-Cg cycloalkyl residue which is optionally substituted with one or more alkyl groups, an aromatic or aromatic-aliphatic hydrocarbon residue which is optionally substituted with one or more C^-C^-alkyl- and/or C1-C4~ alkoxy- and/or C^-C4~ alkylthio- and/or halogen- and/or nine true subst ituen ter or a hydrocyclic hydrocarbon residue, ;R2 denotes hydrogen, a C-^-Cg alkyl residue or an optionally substituted aromatic hydrocarbon residue, ;R3 denotes hydrogen, a C^-Cg alkyl residue, an optionally substituted aromatic hydrocarbon residue, a benzyl residue or hydroxyl group, ; R^ denotes hydrogen, a C^-C^-alkyl residue, an optionally substituted aromatic hydrocarbon residue, a benzyl residue, a C^-C^-alkoxy residue or the hydroxyl group, and ;n denotes 0 or 1.;The new compounds are suitable in surprising degree; for combating problem weeds with a compatibility in s respectability to soybeans, potatoes, cotton, corn and wheat that surpasses the previously known means. With these properties, they constitute a major technical advance. It is known that, for economic reasons, the most important agricultural crops are more and more closely interspersed with each other. When there are weeds underneath, which is common, and which with current weed control techniques are difficult to control, conditions arise that easily lead to the dominance of such species. The problem is attempted to be countered, for example, by using full or even increased amounts of herbicide. This often causes damage to the culture. Since the known herbicides can also affect the subsequent culture as residues in the soil, damage to this also often occurs. An improved herbicide is therefore desired to have good activity against problem weeds, with at the same time good compatibility with several main agricultural crops, which are used in rotation. The new compounds meet these requirements and are characterized by a surprisingly good compatibility with the above-mentioned cultures, whereby they can be used both in the pre-emergence method and the post-emergence method. The herbicidal effect targets several weed species. Abutilon theophrastii, Ipomea ssp., Solanumssp., Viola ;ssp., Echinochloa crus galli, Setaria ssp. can be mentioned as problem weed species that can be well controlled. and Digitaria ssp. The application can take place by incorporation into the soil before sowing, or by pre- or post-emergence. For selective weed control, the amount used amounts to 0.1 to 5 kg of active substance/hectare. In higher quantities, the compounds can also be used for total weed control. The new compounds, in lower amounts of use, can also change the natural development of the plants while achieving different agriculturally or horticulturally noticeable properties. It is clear that not every compound exhibits the same regulatory effect in every plant species, and that this depends on the type of application, application period or application concentration. In general, the change in the natural plant growth can be visually recognized by changes in the size, shape, color or structure of the treated plant or its parts. For example, the following developmental changes in the plants caused by the new compounds can be mentioned: inhibition of vertical growth, inhibition of root development, intensification of the freshness of the plant dye, leaf fall. Among the new compounds with the described properties, those of the above stated general formula I in which R 1 denotes a C 1 -C 8 alkyl residue such as e.g. methyl, trimethylmethyl, ethyl, propyl, isopropyl, methylpropyl, n-butyl, isobutyl, tert.-butyl, 2,2-dimethyl-1-propyl, n-pentyl or n-hexyl, ; an acetic acid methyl ester residue such as: an optionally alkyl substituted pea C 1 -C 8 -cycloalkyl residue, such as e.g. cyclopropyl, cyclopentyl, cyclohexyl, methylcyclohexyl, or cyclooctyl; an optionally substituted aromatic hydrocarbon residue such as e.g. phenyl, 4-trimethylmethylphenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 4-fluoro-, phenyl, 4-iodophenyl, 2-chlorophenyl, 3-chlorophenyl, 4- chlorophenyl, 3,4-dichlorophenyl, 3-nitrophenyl, 4-nitrophenyl, 1-naphthyl or 2-naphthyl, an aromatic-aliphatic hydrocarbon residue, such as e.g. benzyl or 4-chlorobenzyl, a heterocyclic hydrocarbon residue such as e.g. thienyl or 2-furyl; R^ t R3°9/or R^ denotes hydrogen, a C-^-C^-alkyl residue such as e.g. methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert.-butyl, 2,2-dimethyl-1-propyl, n-pentyl or hexyl, an optionally substituted aromatic hydrocarbon residue such as e.g. ;phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 4-fluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 3-nitrophenyl or 4 -nitrophenyl, and R^ and/or R^ may additionally denote a C^-C^-alkyl radical, such as e.g. methoxy, ethoxy, propoxy or n-butoxy, or the hydroxyl group, and where n is 0 or 1. Far more excellent action is among these compounds such in which R^ denotes methyl, trimethylmethyl, methylpropyl, n-hexyl, cyclopentyl, cyclohexyl, phenyl , methylphenyl, trimethyl-methylpheny], methoxyphenyl, fluorophenyl, iodophenyl, chlorophenyl, nitrophenyl, benzyl or thienyl, ;R ? denotes hydrogen, methyl or phenyl,;R_ denotes hydrogen, methyl or hydroxyl,;R4 denotes hydrogen, methyl, dimethylmethyl, trimethylmethyl, phenyl, benzyl or hydroxy, and ;n denotes 0 or 1.;The new compounds can be used either alone or in mixing with each other or with other active substances. Depending on the desired purpose, for example the following herbicidal active substances can be used, which can optionally be added immediately before using the new compounds: substituted anilides; substituted anilines; substituted aryloxycarboxylic acids as well as their salts, esters and amides; substituted ethers; substituted arsonic acids as well as their salts, esters and amides; substituted benzimidazoles; substituted benzthiadiazine dioxides; substituted benzoxazines; substituted benzoxazinones; substituted biurets; substituted quinolines; substituted carbamates; substituted aliphatic carboxylic acids as well as their salts, ;esters and amides; substituted n-arylsulfonyl-N *-triazinyl-urea derivatives substituted aromatic carboxylic acids as well as their salts,

esters and amides

substituted carbamoylalkyl thiol or dithiophosphates substituted quinazolines

substituted cycloalkylamidocarbonthiol acids as well as theirs

salts, esters and amides

substituted cycloalkylcarbonamido-thiazoles

substituted dicarboxylic acids as well as their salts, esters and amides

substituted dihydrobenzofuranyl sulfonates substituted disulfides

substituted dipyridylium salts

substituted dithiocarbamates

substituted dithiophosphorus acids as well as their salts, esters

and amides

substituted uric acids

substituted hexahydro-1H-carbothioates substituted hydantoins

substituted hydrazides

substituted hydrazonium salts

substituted isoxazole pyrimidones

substituted imidazoles substituted isothiazolepyrimidones

substituted ketones

substituted naphthaquinones

substituted aliphatic nitriles

substituted aromatic nitriles

substituted oxadiazoles

substituted oxadiazones

substituted oxadiazolidinones

substituted oxadiazinediones

substituted phenols as well as their salts.and. ester substituted phosphoric acids as well as their salts, esters and

amides

substituted phosphonium chlorides

substituted phosphonalkylglycines

substituted phosphites

substituted phosphoric acids as well as their salts, esters and

amides

substituted piperidines

substituted pyrazoles

substituted pyrazolealkylcarboxylic acids as well as their salts,

esters and amides

substituted pyrazolium salts

substituted pyrazolium alkyl sulfates

substituted pyridazines

substituted pyridazones

substituted pyridine carboxylic acids as well as their salts,

esters and amides

substituted pyridines

substituted pyridine carboxylates

substituted pyridinones

substituted pyrimidines

substituted pyrimidones

substituted pyrrolidine carboxylic acids as well as their salts,

esters and amides

substituted pyrrolidines

substituted pyrrolidones

substituted arylsulfonic acids as well as their salts, esters

and amides

substituted styrenes

substituted tetrahydro-oxadiazinediones

substituted tetrahydro-oxadiazolediones

substituted tetrahydromethanoindenes

substituted tetrahydro-diazole thiones

substituted tetrahydro-thiadiazine thiones

substituted tetrahydro-thiadiazolediones

substituted thiadiazoles

substituted aromatic thiocarboxylic acid amides substituted thiocarboxylic acids as well as their salts, esters

and amides

substituted thiol carbamates

substituted thioureas

substituted thiophosphoric acids as well as their salts, esters

and amides

substituted triazines

substituted triazoles

substituted uracins

substituted uretidine diones

In addition, other additives can also be used, e.g. non-phytotoxic additives, which with the herbicides provide a synergistic increase in effectiveness, such as wetting agents, emulsifiers, solvents and oily additives.

Appropriately, the new active substances or mixtures thereof are used in the form of preparations such as powders, liquids, granules, solutions, emulsions or suspensions, with the addition of liquid and/or solid carriers,

respectively diluents, and possibly wetting agents, binding agents, emulsifying agents and/or dispersing aids.

Suitable liquid carriers are e.g. water, aliphatic and aromatic hydrocarbons such as benzene, toluene, xylene, cyclohexanone, isophorone, dimethylsulfoxide, dimethylformamide and further mineral oil fractions.

Mineral soils such as

e.g. clay sieve, silica gel, talc, kaolin, attapulgis clay, limestone, silicic acid and plant products, e.g. flour.

Surface-active substances can be mentioned e.g. calcium lignin sulfonate, polyoxyethylene alkyl phenol ether, naphthalene sulfonic acids and their salts, phenol sulfonic acids and their salts, formaldehyde condensates, fatty alcohol sulfates as well as substituted benzene sulfonic acids and their salts.

The amount of active ingredient in the various preparations can vary within wide limits. For example, the agent contains 5 to 95% by weight of active ingredient, 95 to 5% by weight of liquid or solid carrier, as well as possibly up to 20% by weight of surfactants.

Delivery of the agent can take place in the usual way, e.g.

with water as carrier in spray liquid quantities of 100 to 5000 l/ha. Application of the agent in the so-called Low-Volume and Ultra-Low-Volume method is also possible, as well as application in the form of so-called microgranules.

For the preparation of the preparations, e.g. the following ingredients are used:

A. Spray powder

a) 80% by weight active substance

15" kaolin

5 "surfactant based on the sodium salt of N-methyl-N-oleyl-taurine and the calcium salt of lignin sulphonic acid.

b) 50% by weight active ingredient

40 " clay minerals

5 " cellulose pitch

5," surfactants based on a mixture of calcium salts of ligninsulfonic acid with alkyl-phenol polyglycol ether.

c) 20% by weight active ingredient

70 " clay minerals

5 " cellulose pitch

5 "surfactants based on a mixture of calcium salts of lignin sulphonic acid with alkyl-phenol polyglycol ether.

d) 5% by weight active ingredient

80 clay sieve

10 " cellulose pitch

5 surfactants based on a fatty acid condensation product.

B. Emulsion Coheshtrate

20% by weight active ingredient

40 " xylene

35 " dimethylsulfoxide

5 " of a mixture of nonylphenylpolyoxyethylene or calcium dodecylbenzene sulphonate.

The new. compounds can be prepared by

a) compounds of general formula:

reacted with compounds of general formula: or with compounds of general formula: or with compounds of general formula:

in the presence of bases, and, if desired, that the isomers are separated by column chromatography, or

b) compounds of general formula:

reacted with compounds of general formula:

or

c) compounds of general formula:

is reacted with thiosemicarbazide of formula:

to compounds of general formula:

after which these are subsequently reacted in the presence of bases with compounds of the general formula:

or with compounds of general formula:

during the formation of compounds of general formula:

which in the presence of basic catalysts are cyclized to the desired process products of general formula I, or that d) if R^ denotes a C^-Cg-alkylcarboxylic acid residue or a C-^-Cg-alkylcarboxylic acid^ester residue, ■ that acetylenic dicarboxylic acids or their esters-of general formula:

reacted with compounds of general formula:

during the formation of compounds of general formula:

and that these in the presence of bases are cyclized to compounds of

general formula:

which are isomerized to the desired process products of general formula I in which R 1 , R 2 , R 2 r R 2 and n have the meanings indicated above, and R denotes hydrogen or C 2 -C 3 -alkyl.

The starting compounds for the production of the new compounds are known in and of themselves or can be produced according to known methods.

The reaction of the reaction partners takes place between 0 and 120°C, generally, however, between room temperature and the corresponding reaction mixture reflux temperature.

The reaction duration is 1 to 72 hours.

For the production of the new compounds, the reactants are used in approximately equimolar amounts. Suitable reaction media are solvents that are inert to the reactants. The choice of solution or suspending agent, depends on the corresponding starting compound and the acid acceptor used or base. As a solution suspending agent can be mentioned, for example, ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane, aliphatic and aromatic hydrocarbons such as petroleum ether, cyclohexane, hexane, heptane, benzene, toluene and xylene, carboxylic acid nitriles such as acetonitrile, and carboxylic acid amides such as dimethylformamide.

Organic bases such as e.g. triethylamine, N,N-dimethylaniline and pyridine bases, or inorganic bases such as oxides, hydroxides and carbonates of alkaline earth and alkali metals. Liquid bases such as pyridine can also be used as a solvent.

The new compounds produced according to the above-mentioned methods can be isolated from the reaction mixture by conventional methods, for example by distilling off the solvent used at normal or reduced pressure, or by precipitation with water.

The new compounds are usually colorless and odorless crystalline materials that are sparingly soluble in water and aliphatic hydrocarbons, moderately to well soluble in halogenated hydrocarbons such as chloroform and carbon tetrachloride, ketones such as acetone, carboxylic acid amides such as dimethylformamide, sulfoxides such as dimethyl sulfoxide, carboxylic acid nitriles such as acetonitrile, and lower alcohols such as methanol and ethanol.

Suitable solvents for recrystallization are carbon tetrachloride, chloroform, toluene, acetonitrile and acetate in particular.

The following examples illustrate the preparation of the new compounds.

Example 1

302 g (3.6 mol) of sodium bicarbonate and 137.5 g (0.72 mol) of dibromoethane were introduced into 700 ml of 2-propanol, and this suspension was heated to reflux. Into this boiling mixture was added dropwise a mixture consisting of 61 g (0.36 mol) of 3-mercapto-6-(4-methylphenyl)-4,5-dihydro-[1,2,4]-triazine-5 -on, 146 ml of 10% caustic soda and 1500 ml of 60% aqueous 2-propanol. The mixture was then heated to reflux for 2 hours, undissolved sodium bicarbonate was filtered off and evaporated in vacuo to dryness. The solid residue obtained was washed with 500 ml of 5% caustic soda and filtered again. The residue was separated by column chromatography on silica gel with ethyl acetate as eluent. 28.8 g (32% of theoretical) were obtained

of 3-(4-methylphenyl)-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one. M.p.: 193°C.

Example 2

480 g (0.21 mol) 3-mercapto-6-(4-methoxyphenyl)-4,5-dihydro-[1,2,4]-triazin-5-one and 100 g (0.5 mol) 1, 3-dibromo-propane was reacted analogously to the reaction conditions specified in example 1. After chromatographic separation, 7.7 g (14% of theory) of 3-(4-methoxyphenyl)-4,6,7,8-tetrahydro-4H-[1,3]-thiazino-[2,3- c][1,2,4]-triazin-4-one.

M.p.: 181°C.

Example 3

18.5 g (0.1 mol) 3-mercapto-6-trimethylmethyl-4,5-dihydro-[1,2,4]-triazin-5-one, 432 g (0.2 mol) 2,3-dibromobutane and 258 g (0.2 mol) of ethyldiisopropylamine was dissolved in 200 ml of acetonitrile and was heated for 48 hours to the reflux temperature. The mixture was poured into ice water, and the precipitate was filtered off and separated by chromatography on silica gel with ethyl acetate as eluent. 8.1 g (34% of theory) of 3-trimethylmethyl-6,7-dihydro-6,7-dimethyl-4H-thiazolo-[2,3-c][1,2,4]-triazine were obtained -4-on. M.p.: 134°C.

Example 4

19.8 g (0.1 mol) of 2-hydrazino-4,5-dihydro-thiazolehydro-r bromide was dissolved in 200 ml of ethanol and then 20 ml of 10% aqueous sodium hydroxide solution and 23.4 g (0, 1 mol) of 4-trimethylmethylphenyl-glyoxylic acid ethyl ester, and the mixture was heated for 4 hours to the reflux temperature, was poured into ice water, the precipitate was filtered off and recrystallized from ethyl acetate. 18.5 g (65% of theory) of 3-(4-trimethylmethylphenyl)-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazine-4 were obtained -on.

M.p.: 203°C.

Example 5

19.6 g (0.1 mol) 2-hydrazinothiazole hydrobromide and

16.4 g (0.1 mol) of phenylglyoxylic acid methyl ester were reacted analogously to example 3. 9.8 g (43%Vav theoretical) were obtained

of 3-phenyl-4H-thiazolo-[2,3-c][ 1, 2,4]-triazin-4-one.

M.p.: 181°C.

Example 6

12.9 g (0.1 mol) of 2-hydrazino-2,4,5,6-tetrahydro-2H-[1,3]-thiazine and 16.4 g (0.1 mol) of phenylglyoxylic acid methyl ester were reacted as described in example 3. 18.4 g (75% of theory) of 3-phenyl-4,6,7,8-tetrahydro-4H-[1,3]-thiazino-[2,3-c][1 ,2,4]-triazin-6-one.

M.p.: 155°C.

Example 7

20.5 g (0.1 mol) 3-mercapto-6-phenyl-4,5-dihydro-[1,2,4]-triazin-5-one, 18.4 g (0.2 mol) chloroacetone and 80 ml of 10% aqueous sodium hydroxide solution was stirred in 250 ml of ethanol for 3 hours at 60°C. The mixture was acidified with dilute hydrochloric acid and the reaction solution was cooled. The precipitate that precipitated was filtered off and purified by column chromatography on silica gel with acetone/petroleum ether (1:1) as eluent. 5.10 g (21% of theory) of 3-phenyl-6-methyl-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one were obtained.

M.p.: 158°C.

Example 8

Analogous to example 7, 20.5 g (0.1 mol) of 3-mercapto-6-phenyl-4,5-dihydro-[1,2,4]-triazin-5-one was reacted with 39.8 g (0 .2 mol) bromoacetophenone. After column chromatographic separation, 4.58 g (15% of theory) of 3,6-diphenyl-. 4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one.

M.p.: 125°C.

Example 9

20.4 g (0.1 mol) of 3-mercapto-6-phenyl-4,5-dihydro-[1,2,4]-triazin-5-one was dissolved in 100 ml of dioxane plus 100 ml of dimethylformamide, was added 20 ml of a 50% chloroacetaldehyde solution and was stirred for 6 hours at 60°C. The reaction mixture was poured into ice water, the precipitate was separated by column chromatography with ethyl acetate/methanol (9:1) as eluent

medium. 3.7 g (15% of theory) of 3-phenyl-6-hydroxy-6,7-dihydro-4H-thiazolo-[2,3-c]11,2,4]-triazin-4-one were obtained . M.p.: 213°C.

Example 10

15 g (0.073 mol) of 3-mercapto-6-phenyl-4,5-dihydro-[1,2,4]-triazin-5-one was dissolved hot in 800 ml of acetonitrile, 13.5 g (0, 15 mol) of epichlorohydrin and 14.85 g (0.115 mol) of ethyldiisopropylamine, and the mixture was heated for 16 hours at 60°C. The reaction mixture was evaporated in vacuo, and the residue was purified by column chromatography on silica gel

(system acetic ester/ethanol, 9:1). 3.6 g (19% of theory) of 3-phenyl-7-hydroxy-4,6,7,8-tetra-(1,3]-thiazino-[2,3-c]-[1, 2,4]-triazin-4-one with melting point 181°C.

Example 11

15 g (0.1 mol) of phenylglyoxylic acid were dissolved in 1 liter of ethanol. Then a solution of 9.1 g (0.1 mol) of thiosemicarbazide in 500 ml of 5% aqueous acetic acid was added, and the reaction solution was stirred for 15 minutes at 90°C. After cooling, the solvent was evaporated to half in vacuo, the precipitate was filtered off, washed with water and dried at 50°C. The thiosemicarbazone obtained was then dissolved without further purification in 120 ml of a 5% soda solution, 9.2 g (0.1 mol) of chloroacetone in 50 ml of ethanol were added and stirred for 2 hours at 60°C. The mixture was cooled, acidified with 10% hydrochloric acid, and the precipitate that precipitated was filtered off. The precipitate was dissolved in a mixture of 200 ml of pyridine/acetic anhydride (1:1) and was stirred for 3 hours at 60°C. The reaction mixture was poured into 500 ml of ice water, the precipitate that had formed was filtered off, washed with water and recrystallized from acetic acid. 12.9 g (53% of theory) of 3-phenyl-6-methyl-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one with m.p. 158°C.

In an analogous manner to what is described in the preceding examples, the following compounds were prepared using the corresponding starting materials.

In what follows, the preparation of previously known compounds which can be used according to the invention is described.

Example 12

302 g (3/6 mol) of sodium bicarbonate and 137.5 g

(0.72 mol) of dibromoethane was introduced into 700 ml of 2-propanol, and this suspension was heated to reflux. Into this boiling mixture was added dropwise a mixture consisting of 73.8 g (0.36 mol) of 3-mercapto-6-phenyl-4,5-dihydro-[1,2,4]-triazin-5-one , 146 ml of 10% caustic soda and 1500 ml of 60% aqueous 2-propanol. The mixture was then heated for 2 hours at reflux temperature, undissolved sodium bicarbonate was filtered off and evaporated to dryness in vacuo. The solid residue obtained was washed with 500 ml of 5% caustic soda and filtered again. The residue was purified by column chromatography on silica gel with ethyl acetate as eluent. 28.8 g (34% of theory) of 3-phenyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one were obtained.

M.p.: 135°C.

Example 13

Analogous to example 8, 14.3 g (0.1 mol) of 3-mercapto-6-methyl-4,5-dihydro-[1,2,4]-triazin-5-one was converted to 7.4 g (44 % of theory) 3-methyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one. M.p.: 171°C.

Example 14

19/8 g (0/1 mol) of 2-hydrazino-4,5-dihydrothiazbl hydrobromide was dissolved in 200 ml of ethanol, then 80 ml of 10% aqueous sodium hydroxide solution and 10.2 g (0.1 mol) were added pyruvic acid methyl ester/was boiled once and then, cooled. The precipitate that precipitated was filtered off and recrystallized from ethyl acetate. 11.0 g (65% of theory) of 3-methyl-6/7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one were obtained.

M.p.: 171°C.

Example 15

Analogous to example 10, 16.4 g (0.1 mol) of phenylglyoxylic acid methyl ester was reacted with 19.8 g (0.1 mol) of 2-hydrazino-4,5-dihydro-thiazole hydrobromide to 13.2 g (57% of theoretical) 3-phenyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one.

M.p.: 135°C.

Example 16

40 g (0.2 mol) of 2-hydrazino-4,5-dihydro-thiazole-hydro-bromide was dissolved in 500 ml of 2% caustic soda, this solution was cooled to 5°C and 28 g (0 .2 mol) acetylenedicarboxylic acid methyl ester and was stirred for 2 hours at 25°C. The precipitate that precipitated was filtered off, dissolved in 250 ml of methanol, 25 ml of triethylamine was added and stirred for 1 hour at 25°C. The precipitate was again filtered and boiled under reflux in 500 ml of methanol for 1 hour. The solvent was then removed in vacuo, and the residue was recrystallized from ethyl acetate. 24.1 g (53% of theory) of 3-carbomethoxy-methyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one were obtained with melting point 123°C.

The subsequent examples illustrate the possibilities of use for the new compounds in the form of the previously indicated preparations.

Example 17

In greenhouses, the new compounds indicated in the table were sprayed in a quantity of 5 kg of active substance/ha, dissolved in 500 1

water/ha, on Sinapis, Solanum and Setaria as test plants by the pre- and post-emergence method. 3 weeks after the treatment, the treatment results were assessed, where 0 = no effect, and 4 = destruction of the plants. As can be seen from

table, a destruction of the test plants was generally achieved.

Example 18

In greenhouses, the indicated plants were treated before pre-emergence with the compounds in an amount of 0.3 or 1 kg active substance/ha. For this purpose, the compounds were released as an aqueous solution or suspension with 500 1 water/ha evenly on the soil. The results show that the new compounds, in contrast to the comparison compound, show a better compatibility, resp. better effect.

Example 19

In greenhouses, the indicated plants were treated after preemergence with the indicated compounds in a quantity of 0.3

respectively 1 kg active substance/ha. For this purpose, the compounds were sprayed as an aqueous solution or suspension with 500 1 water/ha evenly over the plants. 3 weeks after the treatment, the new compounds also showed a high selectivity with an excellent effect against the weeds. The comparison compound did not exhibit this selectivity.

Claims (10)

1. Selective herbicidal agent, characterized in that it contains at least one thiazolo- or [1,3]-thiazino-[2, 3-c][1,2,4]-triazinone of general formula: in which R <->^ is a C^-Cg alkyl residue which is optionally interrupted by one or more oxygen or sulfur atoms, a C^-Cg alkylcarboxylic acid residue, an alkylcarboxylic acid ester residue, a C^-Cg cycloalkyl residue which is optionally substituted with one or more alkyl groups, an aromatic or aromatic-aliphatic hydrocarbon residue which is optionally substituted with one or more C1 -C4~ alkyl- and/or C1 -C4~ alkoxy- and/or C^-C^-alkylthio - and/or halogen and/or nitro substituents, or a heterocyclic hydrocarbon residue, R 2 denotes hydrogen, a C 1 -C 8 alkyl radical or an optionally substituted aromatic hydrocarbon radical, R 3 denotes hydrogen, a C 1 -C 8 alkyl radical, an optionally substituted aromatic hydrocarbon radical, a benzyl radical or the hydroxyl group, R^ denotes hydrogen, a C^ -Cg alkyl residue, an optionally substituted aromatic hydrocarbon residue, a benzyl residue, a C^~ C4~ alkoxy residue or the hydroxyl group, and n denotes 0 or 1. 2. Selective herbicidal agent according to claim 1, characterized in that R^ denotes methyl, trimethylmethyl, methylpropyl, n-hexyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, trimethyl methylphenyl, methoxyphenyl/fluorophenyl, chlorophenyl, iodophenyl, ntrophenyl, benzyl, or thienyl, R2 denotes hydrogen, methyl or phenyl, denotes hydrogen, methyl or hydroxyl, R 1 denotes hydrogen, methyl, dimethylmethyl, trimethylmethyl, phenyl, benzyl or hydroxyl, and n denotes 0 or 1. 3. 3-trimethylmethyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one. 4. 3-cyclohexyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one. 5. 3-thienyl-6,7-dihydro-4H-thiazolo-[2,3-c] [1,v2,4]-triazin-4-one. 6. 3-Phenyl-4,6,7,8-tetrahydro-4H-[1,3]-thiazino-[2,3-c]-[1,2,4]-triazin-4-one. 7. 3-cyclopentyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one. 8. 3-Phenyl-6-methyl-6,7-dihydro-4H-thiazolo-[2,3-c] [1,2,4]-triazin-4-one. 9. Selective herbicidal agent according to claims 1 and 2, characterized in that it contains 3-phenyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one , 3-methyl-6,7-dihydro-4H-thiazolo-[2,3-c][1,2,4]-triazin-4-one and/or 3-carbomethoxymethyl-6,7-dihydro-4H- thiazolo-[2,3-c][1,2,4]-triazin-4-one. 10. Process for the production of thiazolo- and [1,3]-thiazino-[2,3-c][1,2,4]-triazinones according to claim 1, characterized by ata) compounds of general formula: reacted with compounds of general formula: or with compounds of general formula: or with compounds of general formula: in the presence of bases, and, if desired, that the isomers are separated by column chromatography, or b) compounds of general formula: reacted with compounds of general formula: or c) compounds of general formula: is reacted with thiosemicarbazide of formula: to compounds of general formula: after which these, in the presence of bases, are reacted with compounds of the general formula: or with compounds of general formula: during the formation of compounds of general formula: which in the presence of basic catalysts are cyclized to the desired process products of general formula I, or d) if R^ denotes a C^-Cg-alkylcarboxylic acid residue or a C^-Cg-alkylcarboxylic acid ester residue, that acetylenic dicarboxylic acids or their esters of the general formula: reacted with compounds of general formula: during the formation of compounds of general formula: after which these, in the presence of bases, are cyclized to compounds of the general formula: which are isomerized to the desired process products of general formula I in which R 1 , R 2 , R 3 , R 1 and n have the meanings given above and R denotes hydrogen or C 1 -C 3 -alkyl.