CA1096379A

CA1096379A - Trimethylperhydroazepine-1-thiocarboxylic acid s- ethyl esters, process for the manufacture of these compounds and also their use as herbicides

Info

Publication number: CA1096379A
Application number: CA282,291A
Authority: CA
Inventors: Ludwig Nusslein; Friedrich Arndt
Original assignee: Schering AG
Current assignee: Bayer Pharma AG
Priority date: 1976-07-16
Filing date: 1977-07-07
Publication date: 1981-02-24
Also published as: IL52498A; BG32413A3; SU691088A3; RO71240A; CS192488B2; NO146094B; PL103046B1; AT360265B; IL52498A0; PL199634A1; CH631709A5; AU2644477A; IE45759B1; BE856861A; NL7706148A; FR2358397A1; PT66813B; SU629852A3; DE2632676A1; NO146094C

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides trimethylperhydro-azepine-1-thiocarboxylic acid S-ethyl esters, useful as herbicides.

Description

10~(~37~

The present invention is concerned with new trimethyl-perhydroazepine-l-thiocarboxylic acid S-ethyl esters, a process for the manufacture of these compounds and also their uses as herbicides.
It has already been known -that alkylenimino-carbothiol-ates are herbicidally active (United States Patent Specification No. 3,198,786). However, these compounds exhibit sufficient selective-herbicidal properties only in certain crops of useful plants, for example in rice crops for combating Echinochloa spp.
The problem upon which the present invention is based has, therefore, been to provide an agent of the kind in question, which has a wide spectrum of selectivity towards crop plants and a very good herbicidal action against weeds.
This problem is solved in accordance with the present invention by the esters defined in the following paragraph.
The present invention accordingly provides 3,3,5-trimethylperhydro-azepine-l-thiocarboxylic acid S-ethyl ester of the formula Ia f~~

~ ~ N-CO-5-C2H5 (Ia) and 3,5,5-trimethyl-perhydro-azepine-1-thiocarboxylic acid S-ethyl ester of the formula Ib - > ~ N-CO-S-C H

H3C ~ ~ (Ib) , more especially an isomeric mixture of the ester of the formula Ia and the ester of the formula Ib.
`~

~163~9 The compounds of the present invention are distinguished by an outstanding herbicidal action especially against mono-cotyledonous weeds, for example Avena, Alopecurus, Echinochloa, Setaria, Digitaria, Sorghum and Poa.
Owing to their excellent selective properties, the compounds can be used in agricultural crops, for example cauliflower, beetroot, tomato, cotton and soya crops.
The compounds of thepresent invention can also be used in maize and sorghum, it being of advantage to mix antidotes, for example 8-naphthalic anhydride or N,N-diallyldichloracet-amide, with the seed grain or spraying preparation respectively.
A further advantage of the compounds of the present invention is that they also have growth-regulating properties.
The compounds act satisfactorily even at rates of application from 1 kg of active substance per hectare, and, owing to their surprisingly wide spectrum of selectivity, can be used in quantities of up to 8 kg of active substance per hectare before sowing by incorporation in the soil.
The present invention accordinly also provides a herbicidal preparation which comprises an ester selected from the ester of the formula Ia and the ester of the formula Ib, in admixture or conjunction with a suitable carrier. More especially, the preparation comprises an isomeric mixture of the ester of the formula Ib, in admixture or conjunction with a suitable carrier.
The present invention further provides a method of ; protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with an ester selected from the ester of the formula Ia and the ester of the formula Ib, more especially an isomeric mixture of the ester of the formula Ia and the ester of the formula Ib.
The present invention further provides a method of 637~\

protecting a crop area against weeds, wherein the crop area is treated with an ester selected from the ester of the formula la and the ester of the formula Ib, more especially an isomeric mixture of the ester of the formula Ia and the ester of the formula Ib.
The present invention further provides a pack which comprises an ester selected from the ester of the formula Ia and the ester of the formula Ib, more especially an isomeric mixture of the ester of the formula Ia and the ester of the formula Ib, together with instructions for its use as a herbicide.
The compounds of the present invention can be used either alone or in admixture with other active substances.
Depending on the purpose desired, there are mentioned in this connection by way of example the following herbicidally active substances, which, if desired, may be added immediately before the use of the compounds of the present invention:
substituted anilines, substituted aryloxycarboxylic acids and also salts, esters and amides thereof, substituted ethers, substituted arsonic acids and also salts, esters and amides thereof, substituted benzimidazoles, substituted benzisothiazoles, substituted benzthiadiazinone dioxides, substituted benzoxazines, substituted benzoxazinones, substituted benzthiazoles, substituted benzthiadiazines, substituted biurets, substituted quinolines, substituted carbamates, substituted aliphatic carboxylic acids and also salts, esters and amides thereof, substituted aromatic carboxylic acids and also salts, esters and amides thereof, substituted carbamoylalkyl-thio- or dithio-phosphates, substituted quinazolines, substituted cycloalkylamidocarbothiolic acids and also salts, esters and amides thereof, substituted cycloalkyl-carbonamido-thiazoles, substituted dicarboxylic acids and also salts, esters and amides thereof, substituted dihydrobenzofuranyl sulphonates, substituted disulphides, substituted dipyridylium 1~3637~31 salts, substituted dithiocarbamates, substituted dithiophosphoric acids and also salts, esters and amides thereof, substituted ureas, substituted hexahydro-lH-carbothioates, substituted hydantoins, substituted hydrazides, substituted hydrazonium salts, substituted isoxazolepyrimidones, substituted imidazoles, substituted isothiazolepyrimidones, substituted ketones, substituted naphthoquinones, substituted aliphatic nitriles, substituted aromatic nitriles, substituted oxadiazoles, substituted oxadiazinones, substituted oxadiazolidinediones, substituted oxadiazinediones, substituted phenols and also salts and esters thereof, substituted phosFhonic acids and also salts, esters and amides thereof, substituted phosphonium chlorides, substituted phosphonalkylglycines, substituted phosphites, substituted phosphoric acids and salts, esters and amides thereof, substituted piperidines, substituted pyrazoles, substituted pyrazolalkylcarboxylic acids and also salts, esters and amides thereof, substituted pyrazolium salts, substituted pyrazolium alkyl sulphates, substituted pyridazines, substituted pyridazones, substituted pyridine carboxylic acids and also salts, esters and amides thereof, substituted pyridines, substituted pyridine carboxylates, substituted pyridinones, substituted pyrimidones, substituted pyrrolidine carboxylic acids and also salts, esters and amides thereof, substituted pyrrolidines, substituted aryl sulphonic acids and also salts, esters and amides thereof, substituted styrenes, substituted tetrahydro-oxadiazinediones, substituted tetrahydromethanoindenes, substituted tetrahydro-diazole-thiones, substituted tetrahydro-thiadiazine-thiones, substituted tetrahydro-thiadiazolediones, substituted thiadiazoles, substituted aromatic thiocarboxylic acid amides, substituted thiocarboxylic acids and also salts, esters and amides thereof, substituted thiolcarbamates, substituted thiophosphoric acids and also salts, esters and 637~

amides thereof, substituted triazines, substituted triazoles, substituted uracils and substituted uretidinediones.
There may also be used other additives, for example non-phytotoxic additives, which produce with herbici~es a synergistic increase in action, for example wetting agents, emulsifiers, solvents and oily additives.
The characterized active substances or mixtures thereof are advantageously used in the form of herbicidal preparations, for example powders, strewable preparations, granules, solutions, emulsions or suspensions, with the addition of liquid and/or solid vehicles or diluents and, if desired, of surface-active agents, for example wetting, adherent, emulsifying and/or dispersing agents.
Suitable liquid carriers are, for example, water, aliphatic hydrocarbons, aromatic hydrocarbons, for example benzene, toluene and xylene, cyclohexanone, isophorone, dimethyl sulphoxide and dimethylformamide, and also mineral oil fractions.
As solid carriers there are suitable, for example, mineral earths, for example tonsil, silica gel, talcum, kaolin, attaclay, limestone and silicic acid, and vegetable products, for example meals.
~ s surface-ac-tive agents there may be mentioned, for example, calcium lignin sulphonate, polyoxyethylalkyl-phenyl ; ethers, naphthalene sulphonic acids and salts thereof, phenol sulphonic acids and salts thereof, formaldehyde condensates, fatty alcohol sulphates and also substituted benzene sulphonic acids and salts thereof.
The proportion of active substance in the various herbicidal preparations may vary within wide limits. For example, the preparations may contain approximately 10 to 80% by weight of active compound(s), approximately 90 to 20% by weight of liquid or solid carrier and, if desired, also up to 20~ by weight ~63 7~

of surface-active agent(s).
The active compounds may be applied in the usual manner, for example with water as carrier in quantities of spray liquor of about 100 to 1000 litres per hectare. It is also possible to apply the active compounds by the so-called "low volume" and "ultra-low volume" methods, and also in the form of so-called microgranules.
The present invention further provides a process for the manufacture of an isomeric mixture of the ester of the formula Ia and the ester of the formula Ib, wherein an isomeric mixture (if desired dissolved in a solvent) of trimethyl-perhydroazepines of the formula H/ ~ and H3C ~ H

(a) is reacted, if desired in the presence of an acid-binding agent, with chloro-thioformic acid S-ethyl ester of the formula Cl-CO-S-C2H5 , or (b) is reacted in the presence of a base with carbon oxy-sulphide of the formula O=C=S
to form salts of such a base of the general formulae ~13C ~, -CO-S( )B( ) ' ~ ~
~
~ and 1g~96379 3 '--~-C-s( )B( ) 3~

C~13 `- ~1 in which B represents a cation derived from the base, and the salts are treated with an ethylating agent of the general formula in which Z represents a halogen atom, an ethyl sulphuric acid group or a toluene sulphonic acid group, or (c) is reacted with phosgene of the formula /Cl O = C~

to form trimethylperhydroazepine-l-carboxylic acid chlorides of the formulae H3C~ H3C ~

which are then reacted wlth ethyl mercaptan of the formula or with a salt of such a mercaptan, if desired in the presence of an acid-binding agent.
The products of the process may be isolated in a known manner.
As bases or acid-binding agents there may be used all the usual proton acceptors. For this purpose there are suitable organic bases, for example tertiary amines, for example triethylamine or N,N-dimethylaniline, or pyridine bases, and suitable inorganic bases, for example oxides, hydroxides and carbonates of alkali and alkaline earth metals. Liquid bases G3~

may serve simultaneously as solvents. This applies also to the liquid starting bases, if they are used in excess as acid capturer.
The reaction~f the components is carried out at between 0 and 120C, but generally at room temperature. i-For the synthesis of the compounds of the present invention the reactants are used in equimolar quantities.
Suitable reaction media are solvents inert towards the reactants, either alone or in admixture with water.
10 - Amongst many such reaction media the following may be mentioned by way of example, namely aliphatic and aromatic hydrocarbons, for example petroleum ether, cyclohexane, benzene, toluene and xylene, halogenated hydrocarbons, for example methylene chloride, chloroform, carbon tetrachloride and halogen-ated ethylenes, ether-like compounds, for example diethyl ether, diisopropyl ether, tetrahydrofuran and dioxan, ketones, for example acetone, methyl isobutyl ketone and isophorone, esters, for example methyl and ethyl acetates, acid amides, for example dimethylformamide and hexamethyl-phosphoric acid triamide, and carboxylic acid nitriles, for example acetonitrile.
Finally, the isolation of the compounds of the present invention may be carried out in a manner known per se by distilling off the solvents used under atmospheric or reduced pressure, optionally after treatment with acid or basic agents to remove undesired by-products.
The compounds of the present invention exist as a mixture of the two isomers 3,3,5-trimethyl-perhydro-azepine-1-thio-carboxylic acid S-ethyl ester and 3,5,5-trimethyl-perhydro-azepine-l-thiocarboxylic acid S-ethyl ester in the ratio by weight of 1:1.
The starting compounds for preparing the compounds of the present invention and the isomeric mixtures thereof, 1t~363~,~3 respectively, are known or can be prepared by methods known per se.
The 3,3,5(3,5,5)-trimethyl-perhydro-azepine-1-thio-carboxylic acid S-ethyl ester isomeric mixture of the present invention is a pale yellow coloured oil having a feebly aromatic odour, which is insoluble in water, but readily dissolves in all organic solvents, for example hydrocarbons, halogenated hydro-carbons, ethers, ketones, carboxylic acid esters, carboxylic acid amides, carboxylic acid nitriles, alcohols, carboxylic acids, sulphoxides and many others.
The following Examples illustrate the invention.
Example 1 illustrates the process of the present invention and Example 2 illustrates the possibilities of use of an isomeric mixture of the present invention.
Example 1 66.4 ml of a l:l-isomeric mixture of 3,3,5-trimethyl-and 3,5,5-trimethyl-perhydro-azepine were dissolved in 150 ml of diisopropyl ether, and 25 gms of chloro-thioformic acid S-ethyl ester were added dropwise at room temperature while stirring. The reaction mixture was stirred for a further hour, then extracted by agitation with water, then with dilute hydrochloric acid and again with water, the ether phase was dried over magnesium sulphate, the solvent was distilled off n vacuo and finally the remainder of the solvent was removed under a high vacuum.
45 gms (98% of the theoretical yield) of 3,3,5(3,5,5)-trimethyl-perhydro-azepine-l-thiocarboxylic acid S-ethyl ester having an n20 value of 1.5041 were obtained. By the addition of a sodium hydroxide solution to the first aqueous extract 28.3 gms of the starting base used in éxcess were recovered.
Analysis: Calculated C 62.83% H 10.11% N 6.11%

Found C 62.66% H 10.28% N 5.97%

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Example 2 In a series of tests carried out in a greenhouse the plants listed in the Table below were treated before their emergence with the agents mentioned at the rate of application of 3 kg of active substance per hectare. For this purpose the agents were in each case applied uniformly to the soil in the form of an aqueous dispersion at the rate of 500 litres per hectare, and then worked into the soil. Three weeks after the treatment the results showed that the isomeric mixture of the present invention was better than the agent used for comparison. The results are expressed by a numerical scale extending from 0 to 10, the value 0 representing total destruction and the value 10 representing no damage.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A compound selected from a 3,3,5-trimethyl-perhydro-azepine-1-thiocarboxylic acid S-ethyl ester of the formula Ia (Ia) , and a 3,5,5-trimethyl-perhydro-azepine-1-thiocarboxylic acid S-ethyl ester of the formula Ib (Ib), or a mixture thereof.

2. A compound as claimed in claim 1 which has the formula (Ia).

3. A compound as claimed in claim 1 which has the formula (Ib).

4. An isomeric mixture of 3,3,5-trimethyl-perhydro-azepine-1-thiocarboxylic acid S-ethyl ester of the formula Ia given in claim 1 and 3,5,5-trimethyl-perhydro-azepine 1-thio-carboxylic acid S-ethyl ester of the formula Ib given in claim 1.

5. A process for the manufacture of an isomeric mixture as claimed in claim 4, wherein an isomeric mixture of trimethyl-perhydroazepines of the formulae and (a) is reacted with chloro-thioformic acid S-ethyl ester of the formula Cl-CO-S-C2H5 , or (b) is reacted in the presence of a base with carbon oxysulphide of the formula O=C=S
to form salts of such a base of the general formulae and , in which B represents a cation derived from the base, and the salts are treated with an ethylating agent of the general formula H5C2-Z, in which Z represents a halogen atom, an ethyl sulphuric acid group or a toluene sulphonic acid group, or (c) is reacted with phosgene of the formula to form trimethylperhydroazepine-1-carboxylic acid chlorides of the formulae and which are then reacted with ethyl mercaptan of the formula or with a salt of such a mercaptan.

6. A process as claimed in claim 5, wherein each of the reactions with the chloro-thioformic acid S-ethyl ester and with the ethyl mercaptan or salt thereof is carried out in the presence of an acid-binding agent.

7. A method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with the compound claimed in claim 1, 2 or 3.

8. A method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with the isomeric mixture of claim 4.

9. A method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with the compound(s) ofthe formula Ia and/or Ib given in claim l is/are used for the treatment in a total amount within the range of from 1 to 8 kg per hectare.

10. A method of protecting a crop area against weeds, wherein the crop area is treated with the compound as claimed in claim 1, 2 or 3.

11. A method of protecting a crop area against weeds, wherein the crop area is treated with the isomeric mixture of claim 4.

12. A method of protecting a crop area against weeds, wherein the crop area is treated with the compound(s) of the formula Ia and/or Ib given in claim 1, is/are used for the treatment in a total amount within the range of from 1 to 8 kg per hectare.

13. A method of claim 12, wherein the crop is a cauliflower, beetroot, tomato, cotton, soya, maize or sorghum crop.