IE48779B1 - 1,4-oxaza-spirohydrocarbon derivatives,their preparation and plant protecting compositions containing them - Google Patents

Abstract

1,4-Oxaza-spirohydrocarbon derivatives of the wherein R1, R2 and R3 independently represent hydrogen or lower alkyl; with the proviso that at least one of them is alkyl; and n is 0 or 1, exhibit plant protecting properties. The novel compounds may be made by dichloroacetylation of the corresponding N-unsubstituted bases.

Description

This invention relates to a plant protecting composition. More particularly, this invention relates to a plant protecting composition which comprises as an antidote a new 1,4-oxaza-spirohydrocarbon derivative of the general formula I _ ClgHC - C - N (I) wherein R^, R2 and Rg independently represent a hydrogen atom or a C1-4 alkyl group, with the proviso that at least one of them is an alkyl group; and n is 0 or 1, and optionally one or more herbicides, in admixture with an agriculturally acceptable carrier and/or adjuvant. As carrier there may be used solid and/or liquid carriers, and the adjuvant preferably comprises one or more surface active agents. The term 'plant protecting' refers herein to the protection of desirable crop or ornamental species as opposed to undesirable weed species.

The above-defined derivatives of the general formula I and a process for the preparation thereof are also within the scope of the invention.

It is well known that certain herbicides, in addition to their weed-killing effect, adversely affect the growth of cultivated plants and may cause serious damage.

Some herbicides for example inhibit the growth of cultivated plants, cause growth anomalies or decrease the crop. Selectivity of the herbicides, i.e. tolerance by the cultivated - 3 plants is generally Increased by using herbicide compositions containing two or more active ingredients or by using so-called antidotes in or simultaneously with the herbicide catpositians. Useful antidotes are described for example in the published German patent application (DOS) No. 2,218,097.

It has now surprisingly been found that new derivatives of tne general formula I, wherein R?, K3 and n have the meanings defined above, considerably decrease or even eliminate the undesired damages of cultivated plants caused by herbicides. Said antidotes are especially effective in combination with herbicides of the thiolcarbamate type, thereby increasing their selectivity.

The new derivatives of the general formula I, wherein R^, Rg, R3 and n are as defined above, can be prepared by dichloroacetylating a compound of the general formula II wherein , R„, R, and n have the meanings defined above, e.g. with dichloroacetyl chloride, in the presence of an acid binding agent, preferably triethylamine.

Compounds of the general formula II can be obtained by reacting a cycloalkanone of the general formula HI wherein R^ , Rg, R^ and n are as given above, with ethanolamine [3.A.C.S. 75, 358 (1953)].

The plant protecting compositions according to the invention can be applied to the soil or admixed into the soil in a manner known per se. A direct treatment of the plants or steeping of the seeds is also possible. The antidotes of the general formula I are either formulated together with the herbicide(s) or are employed in the form of separate formulations before, after or simultaneously with the treatment with the herbicide(s).

As it has already been stated, the antidotes according to the invention are preferably used to decrease the undesired effect of herbicidal thiolcarbamate derivatives.

In this way also those thiolcarbamate-type herbicides can be safely used for which the effective and phytotoxic doses are very near or even overlapping. It must, however, not be left out of consideration that the activity of herbicides is stro. gly influenced by factors like soil composition, weather conditions etc.

The antidotes according to the invention can be used in the form of compositions containing two or more herbicide active ingredients. One of said herbicides is preferably a thiolcarbamate derivative.

If the antidote is used in combination with one or more herbicides, it is preferably applied in the same way as known for herbicides alone in the form of suitable ready to use formulations. <· ' The quantity of the antidote may be varied within a wide range depending on the weeds to be controlled, the cultivated plants, the herbicide(s) used and the desired effect. It is generally used in a quantity of 0.001 to 50 parts by weight, preferably 0.1 to 10 parts by weight.

K related to 100 parts by weight of the herbicide.

If compounds of the general formula I are used in plerprotecting compositions, in combination with herbicide active ingredients, the total active ingredient concentraticr is preferably between 0.1 and 95% by weight. (f If compounds of the general formula I are used as separate compositions, said compositions generally contain 0.1 to 95 % by weight, preferably 0.5 to 70 % by weight of antidote.

A preferred representative of the compounds of the general formula I is the N-(dichloroacetyl)-6,6,8-trimethyl-l,4oxaza-spiro*C4.4] nonane.

The compositions according to the invention contain, in addition to the active ingredients, one or more conventional solid or liquid carriers, or diluents, and optionally surface active agents, such as dispersing or amulsifying agents.

As solid carrier or diluent for example talc, gel, oluminium silicates, triealcium phosphate, < , silica - 48779 -6 bentonite can be used.

Typical representatives of liquid carriers or diluents are hydrocarbons and derivatives thereof, such as toluene, xylene, acetophenone, polar solvents, and mineral, vegetable or animal oils.

The surface active agents can have an ionic or anionic character. As surface active agent for example the condensation products of ethylene oxide with nonyl- or octylphenone, alkali metal or 0^0¾ earth metal salts .3 of sulphonic esters and sulphonic acid derivatives, and salts of lignin sulphonic acid can be used.

Application of the compositions according to the invention can be effected by spraying, sprinkling, dusting etc. in the form of suitable formulations, such as tank mixtures, solutions, suspensions, emulsions, wettable powders, dusts, powders, granules. It is preferred to start from concentrated solutions, which can be diluted in the place of application to the desired concentration or can be admixed with separate formulations of the herbicides.

Further details of the invention are illustrated by tht following Example and biological test, which are not intended to limit the scope of the invention in any way.

Example 1 N-(dichloroacetyl)-6,’6,8-trimethyl-l,4-oxaza-spiroC4.^ nonane. lo a mixture of 80 ml. of benzene and 12.67 g. (θ·1 .rtoleo) of 2,2,4-trimethyl-cyclopentanone 6.21 g. (0.1 mol.?;.) - 7 of ethanolamine are added and the reaction mixture is boiled for 3.5 houts while water formed is continuously eliminated. Io a benzene solution of 6,6,8-trimethyl-l,4-oxaza-spiro [4,4J nonane obtained 10.12 g. (0.1 mole ) of triethyl5 amine are added at a temperature not exceeding 15 °C, followed by the portionwise addition of 14.74 g. (0.1 mole ) of dichloroacetyl chloride with stirring, at a temperature of 0 °C to 15 °C, The reaction is strongly exothermic, and therefore sn effective cooling ie required to keep the temperature in the desirdd range. The reaction mixture is then stirred at room temperature for 0.5 hours, whereupon the salt precipitated is dissolved by adding water. The benzene phase is separated, washed with an aqueous sodium hydrogen carbonate solution and subsequently with water, then is dried over anhydrous sodium sulphate. The benzene solution is filtered and washed with a small portion of benzene. By distilling off the solvent 20.4 g. (72.9 %) of the title compound are obtained as a yellow liquid; ηθ = 1.4892.

Biological tests Pots of 30 x 40 x 10 cm. are filled with quartz sand free of organic materials. The surface of the soil is sprayed with a herbicidal composition containing 3-ethyldipropyl— thiocarbamate in an amount of 10 kg. of active ingredient/ha, and simultaneously with an antidote composition containing N-(dichloroacetyl)-6,6,8-trimethyl-l,4-oxaza-spiro ι , _/4.4/nonane in amounts of 0.1, 1, 2, 5 and 10 kg. of active ingredient/ha, respectively. The soil is then - 8 thoroughly mixed and the cultivated plants and weeds to be tested are sown into the soil treated as described above.

For comparison purposes untreated control plants and plants treated with 10 kg./ha of the herbicide S-ethyl5 dipropyl-thiolcarbamate alone and in admixture with kg./ha of Ν,Ν-diallyl-dichloroacetamide (known antidote),are used.

The pots are kept in a green-house, at 21°C to 32°C and watered as necessary.

Results were evaluated 3 to 6.’weeks following the treatment, with respect to selectivity and phytotoxicity.

The following plants were tested: Zea mays, Avena sativa, Papaver somniferum, Trifolium pratense, Sinapis alba Panicum capillare, Setaria viridis, Echinochloa crus-galli.

The results obtained are shown in the following table.

From the data it can be clearly seen that N(dichloroacetyl)-6,6,8-trimethyl-l,4-oxaza-spiro {4.4| nonane has satisfactory antidote effect even in a dose of 0,1 kg./ha i.e. in an amount of 1 % related to the weight of the oq herbicide; in other words, in this dose it protects the crop plants without decreasing the herbicidal effect of the active ingredient. The same effect is achieved only with a 1 kg./ha. dose of the known antidote tested, i.e. with an amount of 10 % related to the herbicide used in the combination.

In the following table: A = a 10:1 mixture of S-ethyl-dipropyl-thiolcarbamate and Ν,Ν-diallyl-dichloroacetamide; Β = S-ethyl-dipropyl-thiolcarbamate; C = N-(dichloroacetyl)-6,6,8-trimethyl-l,4-oxaza-spiro nonane. - 10 Example 2 N—( di chloroacetyl) —7, 7,9—trimethyl—1,4—oxaza—spiro/4. j/decano To a mixture of 8o ml. of benzene and 14.10 g. (o.l mole) '•Τ 3,3,5-trimethyl-cyolohexanone 6.21 g. (o.l moles) of ethanolamine are added and the reaction mixture is boiled for 4-,5 hours, while water formed is continuously eliminated. To the ( ( benzene solution of 7, 7, 9-trimethyl-l,4-oxaza-spiro/5-.§7decane obtained 10.12 g. (o.l mole) of triethylamine are added at a temperature not exceeding 15 °C, followed by the portionwise addition of 14.74 g. (o.l mole ) of dichloroacetyl chloride with stirring, at a temperature of 0 °C to 15 °C. The reaction mixture is then stirred at room temperature for 0.5 hour, whereupon the salt precipitated is dissolved by adding water.

The benzene phase is separated, washed with an aqueous sodium hydrogen carbonate solution, then dried over anhydrous, sodium sulphate. The benzene solution is filtered. By distilling •.“f the solvent and cooling the solution 22.4 g. (76.2 %) of the title compound are obtained. M.p. 121-123 G.

The biological tests were carried out as described in Example 1.

The results obtained are shown in tho table.

In the table: N-(diohloroacetyl)-7,7,9-trimethyl-l,4-oxaza-8pino25.47decanoe b- MO «4- t- CO co MD tn in o oo CM cn co cn co 00 CO b- cn cn 00 CO 779 fi •rl Φ ro φ ο 0) Ή £2.

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Claims (16)

1. CLAIMS:1. 1,4-Oxaza-spirohydrocarbon derivatives of the general formula I (I) R , R 2 and R 3 independently represent a hydrogen atom or a alkyl group; with the proviso that at least one of them is an alkyl group; and n is 0 or 1. » >

2. N-(Dichloroacetyl)-6,6,8-trimethyl-l,4-oxaza-spiro/4.4 J nonane.

3. N-(Dichloroacetyl)-7,7,9-trimethyl-1,4-oxaza-spiro/4.5/ decane.

4. Compounds of claim 1, substantially as described herein.

5. A process for preparing a compound of claim 1 which 15 comprises dichloroacetylating a compound of the general formula II HN (II) 48 7 79 - 13 wherein R^, R^, and n have the meanings defined in claim 1.

6. A process according to claim 5 wherein said compound of general formula (II) is reacted with dichloroacetyl chloride in the presence of an acid-binding agent. 5

7. A process according to claim 5, substantially as illustrated in Examples 1 and 2.

8. A process for increasing the crop safety of herbicidal compositions containing as active ingredients thiolcarbamate derivatives, which comprises applying to the soil or the 10 plants before, after or simultaneously with said herbicidal compositions a crop plant-protecting amount of a compound of any of claims 1—4.

9. A process according to claim 8, substantially as hereinbefore described with reference to the Biological Tests. 15

10. A plant protecting composition comprising a compound of claim 1 or 4 in admixture with an agriculturally acceptable carrier and/or adjuvant.

11. A composition according to claim 10 comprising the compound of claim 2. 20

12. A composition according to claim 10 comprising the compound of claim 3. A8779 - 14

13. A composition according to any of claims 10—12 including at least one herbicide.

14. A composition according to claim 13 wherein said herbi cide is a thiolcarbamate. 5

15. A composition according to claim 13 or 14 comprising 0.1 to 10 parts by weight of said compound and 100 parts by weight of said herbicide.

16. A composition according to claim 10, substantially as described herein with reference to the Examples.