DD147309A5 - N-PHENYL MUSHES, PROCESS FOR THEIR PREPARATION AND THEIR USE AS HERBICIDES - Google Patents

Abstract

The invention relates to herbicidal agents for selective weed control in agricultural crops. The aim of the invention is the provision of agents with improved herbicidal and selective action. According to the invention, the novel agents contain as active ingredient N-phenylureas of the formula I in which Z represents -CF & ind2! -, -CF & ind2! CH & ind2! -, -CF & ind2! CHF- or -CF & ind2! CFCl-; R & exp1! is hydrogen, C & indl-4! -alkyl, C & ind3-5! -alkenyl or C & ind3-5! -alkenyl and R & exp2! is C & ind1-4! alkyl, C & ind3-5! -alkenyl, C & ind3-5! alkynyl or C & ind1-4! alkoxy or R & exp1! and R & exp2! together with the adjacent N atom form a heterocyclic 5- or 6-membered ring, in addition to extenders and / or surface-active agents.

Description

'Herbicides - ι

The present invention relates to herbicidal compositions containing novel fluorine-containing N-phenylureas, to a plurality of processes for their preparation and to their use as herbicides.

Characteristic of the known technical solutions

It has already become known that certain N-phenylureas containing oxygen heterocycles can be used as herbicides, such. B. l- (2,2-dimethyl-l, 3-benzodioxol-5-yl) -3,3 ~ dimethylurea (see DE-OS 25 24 822). However, these prior art ureas do not always satisfy in their weed effect.

Object of the invention

The aim of the invention is the provision of agents with improved herbicidal and selective action.

Presentation of the essence of the invention

The invention has for its object to find compounds which have strong herbicidal and selective properties and which are useful as active ingredients in herbicidal compositions.

There have now been new N-phenylureas of the general formula

NH-C-N Ij V

in which

Z is -CF ₂ -, -CF ₂ CH ₂ -, -CF ₂ CHF- or -CF ₂ CFCl,

R 5 is hydrogen, C,.-Alkyl, C, "alkenyl or C ₃ _j - alkinyl and

R "is C _1-4 -alkyl, C ₃ _ ₅ ~ alkenyl, alkynyl or Cj -'-

C _1-4 -alkoxy is or

12

R and R together with the adjacent N-type a

heterocyclic 5- or 6-ring form, found.

The N-phenylureas of the formula (I) are obtained if

(a) isocyanates of the formula

in which

Z has the meaning given above,

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with amines of the formula

H-N (III),

in which

1 2

R and R have the abovementioned meaning,

if appropriate in the presence of a diluent or

(b) in the event that R ^{2 is} C _1-4 -alkoxy, isocyanates of the formula (II) with hydroxylamine (NH ₂ OH) to give novel hydroxyureas of the formula (IV)

in which

Z has the meaning given above,

and then with an alkylating agent of the formula

XR ³ (V),

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in which

R ^{3 is} C ₁₄ alkyl and

3 *

X is halogen or R is SO4,

in the presence of a base and optionally in the presence of a diluent or

(c) in the event that R ^{1 is} hydrogen and R ^{2 is} C _1-4 alkyl or C ₃ _r alkenyl, anilines of the formula

'K ₂ in which Z has the meaning given above, with isocyanates of the formula

R ⁴ -NCO (VII),

in which R stands for C _1-4 -alkyl or C ₃ _ ₅ -alkenyl,

if appropriate in the presence of a diluent.

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The new N-phenylureas of the formula (I) have strong herbicidal properties.

Surprisingly, the N- * phenylureas according to the invention show a higher herbicidal activity and, in particular, a better selectivity than the chemically closest known active compounds of the same mode of action.

Of the compounds of the formula (I) according to the invention those are preferred in which R is hydrogen

or C, _4- alkyl and R is C, -alkyl, C ₃ _ ₅ -alkynyl

or C 1-6 alkoxy and in which R and R together with the adjacent nitrogen atom form a pyrrolidine, piperidine or morpholine ring.

Very particular preference is given to the compounds of the formula (I) in which R is hydrogen or methyl

and R is methyl or methoxy.

If, for example, 2,2,3-trifluorobenzodioxene-6-yl isocyanate and dimethylamine are used as starting materials, the course of the reaction according to process (a) can be represented by the following formula scheme:

+ HN (CII ₃ ) ₂

NCO V ' ^V """NIT-CN (CTT ₃ ) ₂

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If, for example, 2,2-difluorobenzodioxol-5-yl isocyanate and hydroxylamine are used as starting materials and dimethyl sulphate as alkvating agent, the course of the reaction according to process variant (b) * can be represented by the following equation:

+ NH OH

F.P

(CH ₃ ) ₂ S0 _t

For example, using 6-amino-2,2,3-trifluoro-3-chlorobenzodioxene (1,4) and Ä'thylisocyanat as starting materials, the reaction sequence according to process variant (c) can be represented by the following equation:

+ C ₂ H ₅ NCO

NH-C-NH-C ₉ H ₁ O

The isocyanates to be used as starting materials in process variants (a) and (b) are generally defined by the formula (II). These are in particular the following connections:

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2,2-Difluoro-benzodioxol-5-yl-isocyanate, 2,2-difluoro-benzo-1, ^ dioxene-6-yl-isocyanate, 2,2,3 ^{: i-} trifluoro-benzo-1,4-dioxene -6-yl isocyanate and 2- _r 2,3-trifluoro-3-chloro-benzo-i, 4-dioxene-6-yl-isocyanate.

The isocyanates of the formula (II) are not yet known, but can be prepared by reacting in a first stage compounds of the formula

(VIII)

wherein

10 Z has the meaning given,

optionally nitrated in the presence of a diluent, in a second stage, the resulting nitro compounds of the formula

(IX), wherein Z has the meaning given,

reduced, preferably by catalytic hydrogenation by means of hydrogen, and in a third stage, the thus obtained anilines of the formula

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(VI)

worm

Z has the meaning given,

optionally in the presence of a diluent with phosgene (COCl ₂ ).

The compounds of the formulas (Villa), (IXa) and (VIa)

, / 0

(VIII a) (IXa) (VI a)

in which each Z ^{1 is} -CF ₂ -,

are known (Zh Obsh Khim ^21/3 O ^7-317 (1964) ^ (VIIIa) and (IXa) _7;.... Zh Obsh Khim 3 ±, 628-632 (1961) / 7 (VIa) _7.. These compounds can be prepared in the following way, starting from Brenzkatechin:.

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HF

(VIII a)

(IXa)

The compounds of the formula

where Z "

(VIII b),

represents -CFpCH ₂ - or -CF ₂ CHF-,

as well as the following procedure for their preparation are the subject of a separate older, not previously published protection request (German Patent Application P 28 19 788.8 of 05.5.1978). The compounds of formula (VIII b), d. H. the compounds 2,2-difluoro-benzodioxene (1,4) and 2,2,3-trifluoro-benzodioxene (1,4) can be prepared by using pyrocatechol

HO

HO

in the presence of bases with a fluoroethylene of the formula

C = C ^ "(X),

5 in which

X is halogen (in particular fluorine or chlorine) and

X is hydrogen or halogen (in particular fluorine

or chlorine), 10 reacted.

Specific examples of compounds of the formula (X) are:

Chlorotrifluoroethylene, Bromtrifluoräthylen, Chlordifluoräthylen, Bromdifluoräthylen. Particularly preferred are chlorotrifluoroethylene and chlorodifluoroethylene,

Suitable bases in this reaction are especially the hydroxides of the alkali and alkaline earth metals, but also the carbonates of these metals. Their amount can vary between one and more than three moles per mole of pyrocatechol. An excess has a favorable effect. The reaction can be carried out at temperatures of 20 C

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to 150 ° C, more preferably in the range of 80 - 120 ⁰ C. As the solvent, polar liquids are used. For example, dimethylsulfoxide, dimethylformamide and tetramethylenesulfone, but also ethers such as dioxane or diglyme have proven successful. Preference is given to tetramethylene sulphone.

The compound of the formula

(VIIIc),

wherein Z " ^{1 is} -CF ₂ CFCl-,

i.e. the compound 2,2,3-trifluoro-3-chloro-benzodioxene (1,4) is new. It can be prepared by chlorination of 2,2,3-trifluorobenzodioxene, 4) at temperatures between about 60 ° C and 150 ° C, preferably between about 70 and 130 ° C, under free-radical conditions (see Preparation Examples E).

The nitration of the compounds (VIII) is carried out in a manner known per se. As the nitrating agent, nitric acid or, preferably, "nitrating acid" (nitric acid / sulfuric acid) is used. Diluents which can be used are all organic solvents customary in nitration;

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however, water is preferably used (compare Preparation Examples D).

The nitro compounds of the formula

(IXb)

wherein

Z "" -CF ₂ CH ₂ -, ~ CF ₂ CHF or CF ₂ CFCl- are novel ..

The reduction of the nitro compounds (IX) to anilines is likewise carried out in a manner known per se (cf., for example, Houben-Weyl, Handbook of the Organic Chemistry, Volume XI, 1, pp. 360-472). The reduction is preferably carried out by catalytic hydrogenation by means of hydrogen (cf., Preparation Examples C).

The anilines of the formula

Z ¹¹¹ Y Η. (VIb)

wherein Z "" is -CF ₂ CH ₂ -, -CF ₂ CHF- or -CF ₂ CFCl-,

are also new.

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The phosgenation of the anilines (VI) to give isocyanates and the workup likewise takes place in a manner known per se (compare Preparation Examples B).

The resulting isocyanates of the formula (II) are new.

The in process variant (a) continue to be used as starting materials amines of the formula (III) are well known. As examples may be mentioned in detail:

Methylamine, dimethylamine, methylbutylamine, diisopropylamine, pyrrolidine, piperidine, morpholine, N, O-dimethylhydroxylamine, methylbutynylamine.

The alkylating agents of formula (V) are also well known. As examples may be mentioned:

Methyl chloride, methyl bromide, methyl iodide, xyl bromide, ethyl iodide, n- and iso-propyl iodide, n-butyl bromide, dimethyl fulate and diethyl sulfate.

The isocyanates of the formula (VII) which are furthermore to be used as starting materials are likewise generally known. As examples are given:

Methyl isocyanate, ethyl isocyanate, n- and iso-propyl isocyanate, n-butyl isocyanate, allyl isocyanate.

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Suitable diluents in process (a) are all inert organic solvents, for example hydrocarbons, such as toluene, xylene, petrol, petroleum ether, or chlorohydrocarbons, such as methylene chloride, chloroform, chlorobenzene, further ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran.

The Reaktxonstemperaturen can be varied in process (a) in a wider range. In general, one works between about 10 and 100 C, preferably between about 20 unc 60 C.

In carrying out the process (a), the reaction components are expediently employed in equimolar amounts, but an excess of amine does not damage .in general, the reaction product can be obtained directly by filtration, optionally isolated by distilling off the solvent and further purified by recrystallization ,

The preparation of the compounds of the formula (I) according to process (b) according to the invention is generally carried out in two stages, but can also be carried out in a one-pot reaction.

In general, in the first stage according to process (b), hydroxylamine is initially charged in the presence of an organic solvent, but preferably in aqueous solution. As organic solvents

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21 6 7 f

those in process (a) mentioned in question. The isocyanate of the formula (II) is then added dropwise, if appropriate in one of the diluents mentioned in process (a) The reaction temperature in the first step is between about -10 ° and 30 ° C., preferably between 0 ° and 20 ° C. ,

The resulting hydroxyureas of the formula (IV) can be directly further alkylated or precipitated by adding water and filtered off.

The second stage of process (b) is preferably carried out in the presence of a diluent. In addition to the diluents mentioned in process (a), alcohols such as methanol or ethanol are also suitable.

To carry out the alkylation reaction, a base such as sodium or potassium hydroxide is needed. It is generally used in equimolar amounts to the alkylating agent of which at least twice the equimolar amount, based on (IV), is needed.

The temperature in the second stage of process (b) is between 10 ° and 150 ° C, preferably between 20 ° and 115 ° C, depending on the nature and reactivity of the alkylating agent.

To accelerate the alkylation reaction may optionally be carried out in the presence of a phase transfer catalyst. As a phase transfer catalyst

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tors, crown ethers, quaternary phosphonium or preferably quaternary ammonium salts, such as, for example, tetrabutylammonium chloride or bromide, triethylbenzylammonium chloride or methyltrioctylammonium chloride.

The bisalkylated ureas of formula (I) are separated in the usual way by extraction with an organic solvent from the reaction mixture. After distilling off the solvent, the ureas are optionally purified by recrystallization.

The process (c) according to the invention is carried out in principle in the same way as process (a). Here, with regard to diluent, temperature range and molar ratios, the statements made above for process (a) apply. The preparation of the anilines of the formula (VI) required as starting materials has already been described above (see Preparation Examples C).

The active compounds according to the invention influence plant growth and can therefore be used as defoliants, desiccants, haulm killers, anti-sprouting agents and especially as weed-killers. Weeds in the broadest sense are understood to mean all plants which grow in places where they are undesirable. Whether the substances according to the invention act as total or selective herbicides essentially depends on the amount used.

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2167t

The active compounds of the invention may e.g. used in the following plants:

Dicotyledonous weeds of the genera : Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa , Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea.

Dicotyledonous cultures of the genera : Gossypium, Glycine, Beta, Daucus, Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis, Brassica, Lactuca, Cucumis, Cuburbita. -

Monocotyledonous weeds of the genera : Echinochloa, Setaria, Panicum, Digit'aria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monocharia, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum , Ischemum, sphenoclea, daisy octenium, agrostis, alopecurus, apera.

Monocotyledonous cultures of the genera : Oryza, Zea, Triticum, Hordeum, Avena, Seeale, Sorghum, Panicum, Saccharum, Pineapple, Asparagus, Allium.

However, the use of the active compounds according to the invention is by no means restricted to these genera, but extends in the same way to other plants.

The compounds are useful depending on the concentration for total weed control e.g. on industrial and

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Railway tracks and on paths and squares with and without tree cover. Similarly, the compounds for weed control in permanent crops, e.g. Forest, ornamental, fruit, wine, citrus, nut, banana, coffee, tea, gum, oil palm, cocoa, berry fruit and hop plants and for selective weed control in annual crops are used,

The active compounds according to the invention are preferably suitable for selective weed control in various crops, especially in cereals, cotton and maize.

The active compounds can be converted into the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspension emulsions, active substances impregnated with natural and synthetic substances, ultra-fine capsules.

15 sessions in polymeric materials.

These formulations are prepared in a known manner, e.g. by mixing the active compounds with extenders, ie liquid solvents and / or solid carriers, optionally with the use of surface-active agents, ie emulsifiers and / or

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21671 © ν ¹⁹ -

Dispersants and / or foaming agents. In the case of using water as an extender, e.g. also organic solvents can be used as auxiliary solvents. Suitable liquid solvents are essentially: aromatics, such as xylene, toluene, or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, e.g. Petroleum fractions, alcohols, such as butanol or glycol, and their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide and dimethyl sulfoxide, and water *

15 Suitable solid carriers are:

e.g. natural rock minerals such as kaolins, clays, talc, chalk, Quar2, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals such as fumed silica, alumina and silicates; suitable solid carriers for granules are: e.g. crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules of inorganic and organic flours and granules of organic material such as sawdust, coconut shells, corn cobs and tobacco stalks; suitable emulsifiers and / or foam formers are: e.g. nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. Alkylaryl polyglycol ethers, alkylsulfonates, alkyl sulfates, arylsulfonates and protein hydrolysates; as dispersants may be used: e.g. Lignin-sulphite liquors and methylcellulose.

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In the formulations adhesives such as carboxymethyl cellulose, natural and synthetic powdery, granular or latex-shaped polymers may be used, such as Gu: ru7.iarabicujn, polyvinyl alcohol, polyvinyl acetate.

Dyes such as inorganic pigments, e.g. Iron oxide, titanium oxide, ferrocyan blue and organic dyes such as alizarin, azole-metal phthalocyanine dyes and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.

The formulations generally contain between 0.1 and 95% by weight of active ingredient, preferably between 0.5 and 90%.

The active compounds according to the invention can be used as such or in their formulations also in a mixture with known herbicides for weed control use, Eertigfonr.ulierung or tanka mixture is possible. Also a mixture with other known active substances, such as fungicides, insecticides, acaricides _p naternicides, bird repellents, growth substances, plant nutrients and soil structure preservatives.

20 conditioning is possible.

The active compounds can, as such, warden applied in the form of their formulations or prepared therefrom by dilution weiteras Anwendungsforaen, such as ready solutions, emulsions, suspensions, powders _t pastes and granules. They are used in conventional manner _for example by watering, spraying, atomizing, dusting or scattering *,

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The active compounds according to the invention can be applied both after and in particular before emergence of the plants. They can also be incorporated into the soil before sowing. ,

The amount of active ingredient used can vary within larger ranges. It depends essentially on the type of effect desired. In general, the application rates between O ₁ I and 10 kg of active ingredient per ha, preferably between O ₁ I and 5 kg / ha.

embodiment

The invention will be explained in more detail below on some embodiments.

# I & / PP - 22 -

Production Examples

A) N-phenylureas of the general formula (I)

Example (I) -1 / by method (c) _7

aT ₃

17.3 g (0.1 mol) of 5-amino-2,2-difluorobenzodioxole are dissolved in 100 ml of methylene chloride, and 5.7 g (0.1 mol) of methyl isocyanate in 50 ml of methylene chloride are added dropwise at room temperature. The mixture is stirred for a further 1 hour at room temperature, the product formed is filtered off and dried. The resulting 1-methyl-3- (2,2-difluorobenz-dioxol-5-yl) urea melts at 1 60 161 ⁰ C; Yield 20.4 g (88.8% of theory).

In an analogous manner, the following compounds are obtained / by method (c \ J:

Example structural formula melting point

P C

^{2 Χ}

F ₂ .0

1 ₆₃ ° C

(U-4

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0 CH ₃

(D-3

Example (I) -5 ^ according to method {&] J

pcrVh

^2Α σ ^Λ ^ ^Λ ΝΗ- (| -Ν (0Η ₃ ) ₂

O <*

Dissolve 19.9 g (0.1 mol) of 2,2-difluoro-benzodioxol-5-yl-isocyanate in 100 ml of toluene and passes as long as gaseous dimethylamine until no more isocyanate band can be seen in the IR spectrum. Then the product formed is filtered off and recrystallized from ethanol.

This gives 18.2 g of 1,1-dimethyl-3- (2,2-difluorobenzodioxol-5-yl) urea (75% of theory); Melting point 130 ° C.

In an analogous manner, the following ureas are obtained according to method {a) J:

Example structural formula melting point

(I) -6 -o '^,, ⁰ NH-CN _{(CH3) 2}

7 F ₂ .JOL ^ 153 ° C

a) ₂

Il

(D-8 F ₂ ..Λ ^ 120 ^u C

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.6 i

Example (I) -9

.0.

according to method (a);

19.9 g (0.1 mol) of 2,2-difluoro-benzodioxol-5-yl-isocyanate are dissolved in 100 ml of methylene chloride and 6.1 g (0.1 mol) of N, O-dimethylhydroxylamine are added dropwise. dissolved in 50 ml of methylene chloride, added at room temperature. The mixture is stirred for a further 1 hour, the methylene chloride is distilled off in vacuo and the residue is recrystallized from cyclohexane.

This gives 20.3 g of 1-methyl-1-methoxy-3- (2,2-difluorobenzodioxol-5-yl) urea (78.3% of theory); Melting point 66 ° C.

according to method b):

7.0 g (0.1 mol) of hydroxylamine chloride and 4 g of sodium hydroxide are dissolved in 20 ml of water, and a solution of 19.9 g (0.1 mol) of 2,2-difluorobenzodioxole solution is added dropwise at 10-15 ° C. 5-yl isocyanate in 100 ml of methylene chloride. The mixture is stirred for 15 minutes, 1 g of tetrabutylammonium bromide, and 20.9 vxl dimethyl sulfate, then added dropwise at room temperature slowly 22 g of 40% sodium hydroxide solution, stirred for a further 2 hours, the organic phase is separated, 'washed with 50 jnl Water, dried with sodium sulfate, filtered

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216 71 © - 25 -

and the filtrate is evaporated on a rotary evaporator. The remaining 1-methyl-1-methoxy-3- (2,2-difluoro-benzodioxol-5-yl) urea is overall by 'two-fold recrystallization from cyclohexane * cleans; Yield 17.5 g (67.3% of theory); Melting point 66 ° C.

In an analogous manner, the following ureas are obtained according to methods (a) and

Example structural formula melting point

F ₂ (I) -11 N) - ^ - ^ Ni-CN - 68 ° C

Il ^ ptr 0 ^CH 3

² f

-12 «

fm

ρ U NH-C-N

F -7- <r ^ \ / ° ^CK 3

(D-13 ei

Example (I) -14 / by method (a) J F ₂

: / nh-c-n-ch-c ^ ch

K CIL

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Dissolve 23.1 g (0.1 mol) of 2,2,3-trifluoro-benzo-1, 4-dioxene-6-yl isocyanate in 100 ml of methylene chloride and dropwise 8.3 g (0.1 mol) of N Methyl-1-methyl-propynyl-amine in 50 ml of methylene chloride at room temperature. The mixture is stirred for a further 1 hour and after distilling off the methylene chloride in quantitative yield 1-methyl-1- (1-methylpropinyl) -3- (2,2,3-trifluorobenzodioxene (1,4) -6-yl) urea; Melting point 132C.

Example (I) -15, / according to method (a) 7

-C-Nf] it \ -1

Analogously to Example (I) -14, 23.1 g (0.1 mol) of 2,2,3-trifluoro-benzo-1,4-dioxene-6-yl isocyanate and 7.1 g (0, 1 mol) of pyrrolidine the 1,1-tetramethylene 3- (2,2,3-trifluoro-benzodioxene (1,4) -6-yl) urea, of melting point 144 ° C; Yield 30 g (99% of theory).

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B) isocyanates of the general formula (II) Example (II) -1

NCO

50 g of phosgene in 200 ml of chlorobenzene are introduced at 0 ° C. Then, at 0 ° -5 ° C., 34.6 g of 2,2-difluoro-5-aminobenzodioxole in 40 ml of chlorobenzene are added dropwise. It is allowed to come to room temperature and then heated with further introduction of phosgene 2-3 hours to boiling. The mixture is then boiled for an additional hour without the introduction of phosgene and then the excess phosgene is purged with nitrogen. By fractional distillation in vacuo, the 2,2-difluoro-benzodioxol-5-yl isocyanate of boiling point 9O ° C / 2O mbar. Refractive index n ^ ° = 1.49

In an analogous manner, the following isocyanates are obtained:

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example

structural formula

F ₂ Λ

boiling point

Refractive index ⁿ D

60 C / 0.4 mbar 1, 515

52 C / 0.53 mbar 1.495

(ID-4

CI

65-68 ° C / O, 4 mbar 1,497

fj - 29 -

C) amines of general formula (VI b) Beisoiel (VI b) -1

198 g of 6-nitro-2 _/ 2,3-trifluoro-benzodioxene (1.4) are dissolved in 600 ml of ethanol and 20 g of Raney nickel are added. With stirring, hydrogen is pressurized to 50 bar until saturation at 45 C internal temperature is reached. After expansion, the catalyst is filtered off and the filtrate is distilled. This gives 142 g of 6-amino-2,2,3-trifluoro-benzodioxene (1.4) of boiling point 125-127 ° C / 21 mbar; n ^ ⁰ = 1,501.

In an analogous manner, the following amines are obtained:

Example structural formula boiling point refractive index

(VI b) -2 " J y ^] 13 O-131 ° C /

NH ₂ ¹⁷ ' ^{3 1} ^ "

(VI b) -3 F ^ O "** ^" 12O-121 ° C / 1.5015 Cl ^ΛΗ 2 17.3 mbar

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4 / ii - ³⁰ -

D) Nitroverbindun gene of a ENERAL formula (IX B): Bei Piel (IX b) -1

190 g of 2,2,3-trifluorobenzodioxene (1.4) are initially charged at 5 ° C .; at this temperature, a mixture of 150 ml of nitric acid (D 1.41) and 175 ml of conc. Sulfuric acid added dropwise. The mixture is stirred for 1 hour at 10 ° C, then for 1 additional hour at 20 ° C and finally heated for 5 minutes at 40 C. The cooled mixture is poured onto 500 g of ice and extracted the ¹ , organic phase with methylene chloride. After distilling off the solvent, the residue is distilled in vacuo. This gives 198 g of 6-nitro-2,2,3-trifluorobenzodioxene (1.4) from the boiling

15 point 100 - 102 ° C / 1,33 mbar; n ^ ° = 1.5078.

In an analogous manner, the following nitro compounds are obtained:

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Break index

Example structural formula Yield boiling point

.20

(IX b) -2

NO,

91%. 92-93 ° C / O, 27 mbar 1.534

(IXb) -3

F ₂ ^ J>.

93% 123-125 ° C / 16 mbar 1.506

4710 -32-

E) benzodi-oxened, 4) of the formulas (VIIIb) and (VIIIc) Example (VIII b) -1

1Ί0 g pyrocatechol are submitted zusa.mmen with 70 g of potassium hydroxide in 300 ml of tetramethylene sulfone and heated with stirring within 30 min. At 100 ° C. At a temperature of 100 - 11O ⁰ C 140 g of 1, i-difluoro-2-chloroethylene are introduced (duration about 3 hours). Subsequently, the product is distilled at 20 mbar via a small column into a well-cooled template. The mixture is heated to an internal temperature of 100 ⁰ C. The contents of the template is transferred to a separating funnel and the organic phase separated from the aqueous. This gives 112 g (65% of theory) of 2,2-difluoro-1,4-benzodioxene with a refractive index n _n : 1.4802, which is pure by GC analysis.

Example (VIII b) -2

P ₂

220 g of pyrocatechol and 130 g of sodium hydroxide at 95.degree.-150.degree. C. are introduced into 600 ml of tetramethylenesulphone and, at this temperature, 330 g with stirring

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Trifluoro-chloroethylene introduced. The mixture is then distilled at 20 mbar over a column and captures a fraction of boiling point 20 to 6O ⁰ C / 20 mbar in a well-cooled template. After the HjO phase has been separated off, 332 g of pure 2,2,3-trifluoro-1,4-benzodioxene (yield 87% of theory) of boiling point 54-5 ° C./16 mbar remain; n ^ °: 1.4525.

Example (VIIIc)

50 g of 2,2,3-trifluorobenzodioxene (1.4) are irradiated in 200 ml of carbon tetrachloride at 80 ° C with a UV lamp, and within 3 hours 140 g of chlorine are introduced. After blowing out excess chlorine and hydrogen chloride with nitrogen, the solvent is distilled off. By distillation through a small column to obtain 51 g of 2,2,3-trifluoro-3-chloro-benzodioxene (1.4) of boiling point 57-59 ° C / 17.3 mbar; n ^ ^u = 1.4598.

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i -g if _ 34 _

Pre-emergence T. _Λ

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weight of active compound is mixed with the stated amount of solvent, the indicated amount of emulsifier is added and the concentrate is diluted with water to the desired concentration.

Seeds of the test plants are grown, poured into normal soil and doused with the preparation of active compound after 24 hours. "The amount of water per unit area is expediently kept constant. The concentration of active substance in the preparation does not play a role, the decisive factor is only the amount of active ingredient per unit area. After three weeks, the degree of damage to the plants is rated in % damage in comparison with the development of the untreated control. It means:

O % = no effect (as untreated control) 100 % = total destruction

In this test, the N-phenylureas of the formula (I) according to the invention have very good activity, in particular the active compounds according to Preparation Examples (I) -5, (I) -7,

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216710. - ³⁵ -

Example II

Post-emergence test ί

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weight of active compound is mixed with the stated amount of solvent, the indicated amount of emulsifier is added and the concentrate is diluted with water to the desired concentration.

With the preparation of active compound is injected test plants, which have a height of 5 - 15 cm so that the particular desired amount of active ingredient per unit area is applied. The concentration of the spray mixture is chosen so that in 2000 1 water / ha, the respective desired amount of active ingredient is applied. After three weeks, the degree of damage of the plants is rated in % damage in comparison to the development of the untreated control. It means:

0 % = no effect (as untreated control) 100 % = total destruction

In this test, the N-phenylureas of the formula (I) according to the invention have very good activity, in particular the active compounds according to Preparation Examples (D-5, (I) -7, (D-9, (I) -11.

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Claims (4)

I ,. A herbicidal composition, characterized by a content of N-phonyiureas of the formula in which Z is -CF 2 -, -CF 2 CH 2 -, -CF 2 CHF- or -CFgCFCl, R is 1 ', is hydrogen, C, -alkyl, C,. Alkenyl, or C. ?? - aralkynyl and ??? R is C1, -alkyl, C.? ! - alkenyl, C 1-6 alkynyl or C 1-6 alkoxy or 1 2 R and R together with the adjacent N atom one heterocyclic 5- or 6-ring, in addition to extenders and / or surfactants. 2. Ancestors for combating undesirable plant growth, characterized in that N-phenylureas according to point run the unwanted plants or their habitat act. 03/25/1980 AP C 07 D / 215 710 / 1β - 37 - 56 387/18 3. Use of N-phenylureas according to item 1, characterized in that they are used to combat
Plant growth can be used. 4. A process for the preparation of herbicidal agents, characterized by mixing N-phenylureas according to item 1 with extenders and / or surface-active agents.