DE3226009A1 - 2,4-HEXADIENE ACID DERIVATIVES SUITABLE FOR WEED KILLING AND PLANT GROWTH REGULATORS - Google Patents

Description

^?> PATENT LAWYERS

dr. V. SCHMIED-KOWARZIK · dr. P. WEINHOLD ■ dr. P. BARZ · Munich DIPL.-ING. G. DANNENBERG · dr. D. GUDEL- dipl-ing. S. SCHUBERT · Frankfurt

APPROVED REPRESENTATIVES AT THE EUROPEAN PATENT OFFICE

SIEGFRIEDSTRASSE β βΟΟΟ MUNICH

TELEPHONE (089) 335024 + 335025 TELECRAMMEt WIRPATENTS TELEXt 5215679

SK / SK

K.2980

Montedison S.p.A.

Foro Buonaparte 31

20121 Milan / Italy

As a weed killer and plant growth regulator suitable 2,4-hexadienoic acid derivatives

The present invention relates to new weed killers Hexadienoxates and in particular to 2,4-hexadienoic acid derivatives which are mono- or disubstituted in the 6-position with weed-killing and plant growth-regulating effects.

The present invention further relates to their use for protecting important agricultural products Weed crops and for their use as plant growth regulators.

One of the most common weed killers used in agriculture is 2,4-dichlorophenoxyacetic acid (trade name: 2,4 D) ₁ whose herbicidal activity was first described by PW Zimmermann | jnd AEHitchcock in Contr.Boyce Thompson Inst., 1j2, 321 (1942).

This compound has excellent herbicidal properties, especially in post-treatment.

However, 2,4 D is a highly volatile compound, and this feature is a serious disadvantage because while and after application, the compound can be transferred to neighboring crops, making them irreparable damage.

Furthermore, the heavy use of 2.4 D has facilitated the development of weeds that act against this ver j binding reslstejit are.

To overcome these disadvantages, numerous chemical compounds have been synthesized, the structure of which is different directly or indirectly from that of 2,4-dichlorophenoxy acetic acid derived.

'S-

_ Sr _

For example, there can be mentioned the naphthoxyacetic acid derivatives (BE-PS 774 748), the phenoxyphenoxyacetic acid derivatives (BE-PS 864 632) and the phenoxyphenoxycrotonic acid derivatives (BE-PS 871 523).

2,4-dichlorophenoxyacetic acid is further endowed with a plant growth-regulating activity, but its _t0 high phytotoxicity prevents its use as a plant growth-regulating agent.

It has now been found that there are 2,4-hexadienoic acid derivatives with a weed-killing activity with high selectivity towards important agricultural crops and with a plant growth-regulating activity are equipped.

The aim of the present invention are therefore the compounds of the general formula

R.
Ar - Y - CH - CH = CH - CH = CH - C -R ¹ (i)

Il

O in which:

₂₅ R is a hydrogen atom or methyl;

Y is an oxygen atom or a divalent sulfur atom

is; ·:

R ^{1 is} a group OR ² , SR ^2, or N (R ² ) ₂ ;

R ^{2 is} hydrogen, C _1-4 alkyl, C 1-4 cycloalkyl, C _2-4 alkenyl, C _2-4 alkynyl, phenyl or benzyl;

Ar is phenyl, pyridyl, naphthyl, or a quinoline nucleus; Phenoxyphenyl or pyridyloxyphenyl, these groups being optionally substituted by one or more substituents selected from halogen atoms, C ₁ _ ₄ alkyl groups, C _1-4 alkoxy groups, or a nitro, cyano, trifluoromethyl, acetoxy, acetamido and methoxycarbonyl group, substituted could be.

The compounds of general formula (I) are herbicidal with (herbicidal) and plant growth regulating activities and with advantage in can be used in agriculture. They are produced by the methods customary in organic chemistry.

A versatile synthesis consists in condensing an alkali salt of the formula

Ar - Y ⁰ M ^ (II)

(in which M © is the cation of an alkali metal, while Ar and Y have the meaning given for formula (I)) with an alkyl ester of the formula

15 R

X - CH - CH = CH - CH = CH - C - OR ² (III)

Il

(in which R ^{2 is} lower alkyl, R is a hydrogen atom • or methyl and X is a chlorine, bromine or iodine atom).

The above reaction gives the compounds of the formula (I) in which R ^{1 represents} the group OR ² and R ^{2 is} alkyl (ester derivatives).

The other compounds of the formula (I) are prepared from these compounds by customary processes. So For example, the carboxylic acids (R = OH) can be prepared by hydrolysis, which convert into the corresponding acyl halides converted and with suitable alcohols, thiols or amines to prepare the compounds of formula (I)

12 2 can be implemented in which R = OR, SR or

N (R ² ) is ₂ .

The condensation between the salt (II) and the ester (III) usually takes place in an inert gas atmosphere and in a polar solvent.

- ⁴ T-

After several hours of stirring at a temperature between room temperature and the boiling point of the solution > means the reaction is ended and the product is isolated by customary methods.

The compounds of formula (I) are in the form of solids or liquids with a high boiling point. 10

The alkali metal salts of the formula (II) are generally known or obtained from known compounds by customary processes easily established connections.

15 Also the compounds of the formula (II) in which R = H,

are known compounds that can be prepared, for example, according to Helv.Chim.Acta 29, 1191 (1946) or J.Chem.Soc, page 866 (1946) are.

As far as is known, the compounds of the formula (II) in which R = CH, are new compounds.

A further object of the present invention are therefore compounds of the formula

25 ■ CH,

X - CH - .CH = CH - CH = CH - C - OR ^ (IV)

Il

in which X stands for a chlorine, bromine or iodine atom

ρ
and RC, _, is alkyl.

These compounds are prepared by halogenation and dehydrohalogenation of alkyl 2,5-heptadienoate, the is a known compound after the following reactions:

CH -CH = CH-CH-CHeCH-COOR ² + X ₃ ) CH ₃ -CH-CH-CH ₂ -CH = CH-COOR

2 bases . _s

CH, -CH-CH-CH ₀ -CH = CH-COOR -5 = - > C ^)

3 I I 2 -nX

X X

The preparation of a compound of the formula (IV) is described in Example 1 described.

As already mentioned, the compounds of the * formula (i) endowed with high herbicidal activity. . Within this class, some compounds show one stronger action against dicotyledon weeds, others against the monocotyledon weeds, being in each Maintain a high level of selectivity towards useful crops. Furthermore, they are during the preroll (i.e. when the weeds have not yet emerged from the earth

20 is) and is active during the overrun.

The best results are obtained by using it during the follow-up period.

As for the weed-killing activity, there will be Compounds of the formula (I) are preferred in which R is a hydrogen atom and Ar is a substituted phenyl group or R is a methyl group and Ar is a phenoxyphenyl or an optionally substituted pyridinoxyphenyl

30 group is.

In agricultural practice, the connections are of the formula (I) can be used per se or in the form of suitable preparations. These preparations include in addition to one or several compounds of the formula (i) as active substance or solid or liquid carrier and optionally surface-active Agents, emulsifiers or other additives.

If desired, other compatible preparations can also be used active substances selected from fertilizers, 5 plant growth regulators and other weed killers, add.

The herbicidal preparations can according to the usual agricultural Processes can be formulated as granules, powders, wettable powders, emulsifiable concentrates, etc.

Depending on the type of preparation and its intended particular use, the active substance can be contained in amounts between 1 to 99 wt .-%.

The amount of preparation or formulation used in the before Weed area to be distributed to protected area varies as a function of various factors, such as the species of the preparation or the formulation and the respective. 20 Effectiveness of the contained, special, active Substance, the type of infestation and its extent, the type of culture as well as climatic and environmental factors.

In any case, the amount of active substance which is used to achieve a satisfactory protection of the crops against weeds is between 0.3 and G kg / ha.

The compounds of the general formula (I) also have interesting plant growth regulators Properties in various fields of application.

For example, they accelerate the setting of flowers, i.e. the development of parthenocarpic fruits without a Pollination has occurred. This ability is commonly used to prepare tomatoes and peppers in Accelerate greenhouse crops.

Another use of the plant growth regulators is to stimulate root growth in cuttings * (small blades).

Another use of the compounds of formula (I) is their utility in reducing shedding of the fruit before harvest, especially in apple trees.

10

The plant growth-regulating effect exerted by the compounds of the formula (I) varies in its extent as a function of the compound and the type of effect required. Within the claimed class of new compounds, various compounds show a plant growth regulating effect which is at least comparable to that of commercially available plant growth regulators with a different structure, if not even better than these in numerous cases

20 is.

In practical use as a plant growth regulator the compounds of the formula (I) can be used in the form of emulsifiable concentrates, with others Formulations are of interest from a practical standpoint because of their particular uses.

The enulsifiable concentrates contain one or several compounds of the formula (i) as the active substance nor solvents and surface-active agents which are suitable. A certain amount of water can also be present in the concentrate.

In carrying out the treatment, the concentrate is used

to the desired concentration of the active substance ■ diluted in water, the concentration for the

Preparation treatment about 10 to 200 mg / l, preferably around 100 mg / l and for a treatment to prevent the Fruit shedding is about 1 to 10 g / hl, preferably around 3 g / hl.

The following examples illustrate the present one Invention.

Example 1

Preparation of methyl 6-bromo-hepta-2,4-dienoate

CH ₃
Br - CH - CH = CH - CH = CH - COOCH,

A solution of 50.9 g (0.3-18 mol) of bromine in 100 ml of CCl ₄ was added dropwise over about 2 hours to a solution of 44.6 g (0.318 mol) of methyl 2,5-heptadienoate (prepared according to GB Chiusoli "La Chimica e l'Industria 41» 506 (1959)) in 50 ml of CCl ₄ , which is kept at -15 ° C. with stirring

was held, added.

When the addition was complete, the temperature was allowed to rise spontaneously to room temperature. Then the reaction mixture was distilled under vacuum and collected boiling at 0.13 mbar and 100-105 ⁰ C fraction.

This gave 65.72 g of methyl 5,6-dibromo-hept-2-enoate formula

CH, - CH - CH - CH ₀ - CH = CH - COOCH ,,

Br Br

63.4 g (0.21 mol) of this ester were then dissolved in 200 ml of methyl ethyl ketone, and 29 g (0.21 mol) were added to the solution Mol) anhydrous potassium carbonate was added.

The reaction mixture was then refluxed for about 30 hours. The solvent became cold by evaporation removed under reduced pressure. The raw product

was again diluted with ethyl ether and with water until washed to achieve a neutral pH.

The ethereal solution was then freed from water and the solvent removed by evaporation under reduced pressure. The crude product was distilled under high vacuum and the b
tion was collected.

distilled and at 80 ⁰ C and 0.13 mbar boiling parliamentary groups

In this way, 26.9 g of the desired product were obtained (elemental analysis and IR analysis corresponded to the assumed structure).
1 H NMR (CDCl ₃ , TMS) _βr

CH ₃ -C ^ -CHg = CH ₀ -CH ₀ = CHg-COOCH ₃

<f (ppm): 1.82 (d, 3H, CH ₃ -CH), 3.76 (s, 3H, COOCH ₃ ), 4.77 (m, 1H, H _A ), 5.7-6, 8 (m, 3H, H _B + H _C + H _D ) 7.0-7.7 (m, 1H, H _D )

/ s = singlet, d = doublet, m = multiplet /.

Example 2

Preparation of methyl 6- (3 ', 5'-dichloro-2'-pyridinoxyphenoxy-hepta-2,4-dienoate

²⁵ ^ ¹ CE

^ci - (OV ^o - ^ 0 / ° ~ ^c "" ^CH * ■ ^GH "" ^{ch = ch} - ^cooch

Into a 100 ml flask equipped with a magnetic stirrer and kept in a nitrogen atmosphere

introduced:

3.2 g (0.0125 mol) of sodium 4- (3 ', 5'-dichloro-2'-pyri-

dinoxy) phenate,

3.2 g (0.0146 mol) of methyl 6-bromo-2,4-heptadienoate and 10 ml of methanol.

The reaction mixture was stirred at a temperature of 0 ° C. for 2 hours.

Then the methanol was evaporated at room temperature and the residue is diluted again with ethyl ether. The ethereal solution was made with dilute aqueous sodium carbonate and then washed with water to neutral pH.

Evaporation of the solvent gave 3.4 g of the desired product which was crystallized from petroleum ether (m.p. 100-103 ⁰ C).
¹ H NMR (CDCl ₃ , TMS)

Cl
¹⁵ /

Cl- / q> -0- fÖ \ -0-CH ^

£ (ppm): 1.45 (d, 3H, CH-CH ₃ ), 3.72 (s, 3H, COOCH ₃ ),

4.85 (m, 1H, H _A), 5.64 to 6.62 (m, 3H, H H _C + _D + _E H)

B is ρ ie I 3.

20 Preparation of methyl 6- (3-trifluoromethylphenoxy) -hexa-2,4-dienoate

0-CH-CH = CH-CH = CH-COOCh

■
25th

To a 100 ml flask fitted with a reflux condenser and magnetic stirrer and kept in a nitrogen atmosphere were placed:
3.6 g (0.02 mol) of sodium 3-trifluoromethylphenate, 4.2 g (0.02 mol) of methyl 6-bromo-hexa-2,4-dienoate and 50 ml of methanol.

^{The reaction mixture was stirred at 35 °} C. for 3 hours in a nitrogen atmosphere.

The methanol was then evaporated and the residue was diluted again with ethyl ether. The ethereal solution was washed with water and _{dried over anhydrous Na 2} SO ^. Then the solvent was evaporated.

* 6.7-8 (m _r 7H, aromatic protons + H)

- 12 -

The residue was distilled under high vacuum and collected at 9O ⁰ C and 0.067 mbär boiling fraction. 3.4 g of the desired product were obtained in this way. ¹ H NMR (CDCU, TMS)

₃ C ^ / q \ -0-

io S (PPm): 3.8 (s, 3H, CH ₃ ), 4.8 (d, 2Ή, CH ₂ ), 5.9-6.8 (m, 3H, Hg + H ^ + Hjj), 7-7.8 (m, 5H, H ^ + aromatic protons).

Example 4

Some representative compounds of the general formula (i) are listed in Table 1 below. The compounds of Table 1 were prepared according to the procedure described in Example 2 or 3. Compounds of Table 1, in which R = OH, were made from the corresponding compounds in which R = OCH ₃ by

20 common hydrolysis process produced.

Si

Compounds of formula (1)

Verb.

Ar

^cl <§r

^ci <o. _t

Ο) "

Cl

O)-

O N

O)-

Table 1 R.

Ar-Y-CH-CH = CH-CH = CH-CR ¹

Il

physical state at room temperature

(2)

O,

fixed; F. 115 C

fixed; 67-68 ° C.

fixed; F. 61-63 C.

fixed; F. 72-74 ⁰ C

fixed; F. 10O ⁰ C

fixed; F. 100 ^U C

fixed; 142 ° C

CD CD O CO

(3) β

CF,

Cl

QF ₃

H C 3

Cl -

V- (O,

F C

OCH

.8th

Table 1 continued

"liquid; Kp.

OH

Oh

004

OCH

OCH

OCH

OCH

_mbar

90 ° C

fixed; M.p. 110-115 C.

fixed; F. 140-150 C and decomposition,

fixed;. .F. 75-80 ° C

• fluid;

fluid; Kp.

fixed; M.p. 62-64 ° C

fixed; M.p. 74-76 ° C

cn ο ο

OCH

8th "

Table 1 continued

fixed; M. 100 ^° C

cn

NC

OCH

fixed; M.p. 114 ^° C

OCH

fixed; F. 50-55 C.

OCH

fixed; 78 ° C

* ft

», HO

'CH

OCH

fixed; F. 55 C

OH

fixed; F .. 155-160 ⁰ C

H C - C - Nile 3 it

OCH

fixed; F. 155 C

CO to K) CD O CD CO

fixed; F. 48-52 ⁰ C

co O

S 8 cn

Table 1 continued

OCH solid; 100-103 ° C

^ Cl

OH solid; F. 105-110 ⁰ C.

OCH . fixed; F. 60-65 ⁰ C

H C-C-NH

OCH 3 solid; 162-166 ° C

CH

OCH

liquid * - ¹ H NMR ** (Γ. ppm)

1.52 (d, 3H), 3.84 (s, 3H), 4.97 (m, 1H), 5.9-6.68 x (m, 3H), 6.78-7.98 (m , 9H)

CH

OCH 3

liquid * ¹ H NMR (S, ppm)

1.42 (d, 3H), 2.23 (s, 3H), 3.65 (s, 3H), 4.95 (m, 1H), 5.6-6.3 (m, 3H), 6 , 5-7.4 (m, 9H

CD O O

S? S. CF 3 O Ck
3 IO
Oi
Tabel
OCH
3 M _ »_»
w ol O ol
1 continuation
fluid*
¹ H NMR (Γ, ppm)
5.55-6.42 (m, 3H), 6.68-7.78 (m, 9H) I.
* ■. Ci
c. - <O> - ° <Ö) - O CH 0Ol
3 fluid*
¹ H NMR (vT, ppm)
1.48 (d, 3H), 3.76 (s, 3H), 4.91 (m. 1H),
5.77-6.66 (m, 3H), 6.77-7.66 (m, 9H) 30th O CH
3 OCH
3 fluid*
¹ H NMR (<f, ppm)
1.42 Cd, 3HK 2.2 (s, 3H), 3.68 (s, 3H),
4.76 (m, 1H), 5.64-6.37 (m, 3H),
6.52-7.53 (m, 8H) 31 ü CH
3 OCH ■
3 fixed; M.p. 100-1O3 ° C. 32
(β)
33 (1) Elemental analysis, IR and NMR data of each compound correspond to those assumed
structure
(2) The melting points given in Table 1 have not been corrected
(3) The preparation of compound No. 8 is described in Example 3
* When heated, this compound decomposes before distillation
** the H, NMR fourths mentioned in the table were obtained by using CDCl, as
Solvent and TMS as internal standard °
(6) The preparation of Compound No. 33 is described in Example 2

CO IS)

K) CT) O O

-Q ₉ - Example 5 - -re - 5 Determination of weed-killing activity Pots of 10 cm upper diameter and 1C containing sandy soil were per pot sown the following weeds: 10 Monocotvledons Echinocloa crus galli Avena fatua Alopecurus myosuroides Sorghum spp. 15th Setaria glauca Digitaria sanguinalis Panichum dichotomiflorum Festuca pratensis Bromus sterilis 20th Lolium italicum Dactilis glomerata Dicotvledonen Stellaria media Ipomea purpurea 25th Vigna sinensis Convolvolus sepium Solanum nigrum Amaranthus retroflexus Clienopodium album 30th Rumex acetosella Veronica persica Each pot was made with the safe unc ) cm height, the 35 with one of the (A) (B) (C) (D) (E) (F) (G) (H) (D (J) (K) (L) (M) (N) (0) (P) (Q) (R) (S) (T) ί good germs the seeds poured the necessary amount of water. The pots were divided into three sentences. The first set was not treated with any herbicides and used as a control.

.- Af-

- 19 -

The second set was treated one day after sowing with an aqueous-acetone dispersion (20 % LVoI./VoI.) Of the compounds according to the invention in order to evaluate the herbicidal activity during the run-up.

The third set was treated 15 days after sowing (ie when the plants, depending on the species, had already reached a height of 5 to 10 cm) with an aqueous-acetone dispersion 20 % v / v) of the compounds according to the invention, to evaluate herbicidal activity during the wake.

All pots were observed in a conditioned environment at temperatures between 15 and 24 ⁰ C, a relative humidity of 70 %, an illumination time of 12 hours and a light intensity of 2000 lux.

20 All pots were uniformly sprayed every two days, with it was ensured that only the soil was moistened, so as to be sufficient for the proper development of the plants Ensure moisture.

28 days after the treatment, the vegetative state of the plants was determined and the corresponding evaluation on a scale from 0 = growth equal to that of the control to 4, complete cessation of growth or death of the plant expressed. The results are

as listed in Tables 2 and 3.

• * W 4
»· * cn UU Table 2 Dose
current sub
kg / ha. A. C. D. Unk
E. rough
P. H I. j M. N '.ΔΌ Herbicidal forerun activity at the specified
Cans 6th 3 Connection no.
(see table 1) 6 · 4th 3 5 2 6th 4th 8th 6th 4th 9 2 3 4th 3 3 4th 4th 3 3 10 10. 30th 15th 20th 25th 30th 35

8 § KSS
Table; 5 weed A. 4th B. C. D. 'E F. 6th H I. J 4th K Cans M. < N Q P. Q οι R. S. T I. Herbicidal trailing activity at the specified 3 4th
4th 4th 4th 4th 4th 4th Connection no.
(see table 1) Dose of act.
Subst .; kg / ha " 4th 4th
3 4th 4th 4th 4th 4th 1 6th
1 2 4th
3 4th 4th 2 4th 4th 2 6th
■ 1 3 4th
3 4th 4th 3 3 3 4th 6th
1 1 Jk Jk 4th 4th 2 4th 4th 6th 6th
1 4th 3 4th
4th 4th
3 4th 4th 4th 8th 6th
1 4th 4th 4th
4th 4th 4th 4th 3 O 6th
2 4th 4th 10 6th
2 4th 4th 3 4th 4th 4th
3 18th 6th 4th 3 28 2 3 i'u e

cn ο ο

Example 6

Selectivity against useful crops during the follow-up period

The compounds of the invention were tested for their phytotoxicity against agricultural crops to determine. By operating as in Example 5 for treatment during the follow-up period, the following Crop damage due to phytotoxicity determined:

Wheat (A ')

beetroot (B ¹ )

15 cucumbers (C)

Parsley '(D')

Celery (E ')

Fennel (F ')

Beans (G ')

so tomatoes (H ')

Carrots (I ¹ )

The phytotoxicity damage was according to the same Expressed on the scale as used in Example 5 for herbicidal activity, 0 being growth as in the control and 4 a complete. Mean cessation of growth or death of the plant. The scored Results are shown in Table 4 below.

Tab elle 4

Phytotoxicity against useful cultures in the
specified doses Dose
current sub.
kg / ha Useful plant A ¹ B ¹ C. D ¹ E ¹ pt G ¹ H' I ¹ Connection no.
(see table 1) 4th
4th 0
1 0
0 1 0 0 0 0 1 0 28
30th

Example 7 Seeding test on tomatoes

Tomato plants grown in a glass house at a temperature of 18 to 21 ^° C., cv. Marmande, were placed in pots with a diameter of 35 cm. During the growth of the plants, the side shoots were constantly removed so that

the plants only had one central stem, to

When the first flower stem showed 3 to 4 flowers, it was treated with an aqueous acetone solution (20% by volume Acetone), which contained a wetting agent and the test product in a concentration of 100 ppm. The handling 15 treatment was repeated after 7 days.

Twelve days after the second treatment, the fruits were harvested and weighed.

For comparison purposes, a set of tomato plants was grown in the same way, but only with an aqueous acetone Solution treated without plant growth regulators.

The test results, expressed as an average Weight of the fruit are listed in Table 5 below; they clearly show that the connections of the general formula (i) have a preparation activity.

so their activity is also comparable or in some Cases superior to those of ß-naphthoxyacetic acid; the latter is a commercially available plant growth regulator, which is used in the glass house for the preparation of tomatoes.

Table 5 Preparing tomato flowers

5 connection no.

(see Table 1) average weight of the fruit; G

1 40.42

2 52.86 9 48.02

₁₀ 18 41.87

23 50.19 ''

26th 41.53

ß-NOA ^ 45.37

Control 17.68 ^

(1) = ß-naphthoxyacetic acid, a commercially available vegetable

growth regulators

(2) = average weight of the fruits of plants that were not treated with a plant growth regulator
Example 8

Activity test against dropping

Apple plants sown in pots and grown in a glass house were treated with an aqueous-acetone dispersion (20 .Vol .- # acetone) that sprayed the test product in a concentration of 30 ppm.

3 days after the treatment, 20 leaves per tree were cut off, whereby only the stalks remained on the branches.

An additional 11 days after treatment, the percentage of stems that came loose when by hand was evaluated slight pressure was applied. As a comparison, an analog test was carried out on apple plants that were only with one aqueous-acetone solution without plant growth regulation

35 treatment agents were treated.

32260Q 9

The test results, expressed as the percentage of stalk fallen, are shown in Table 6 below.

Table 6

The anti-shedding activity in leaves of apple trees

Connection no.
(see Table 1) % of fallen leaf stalks

1 0 6th ■ 6.4 9 25.6 23 14.3 control 67.5

In the present application, ^ 1-4 alkyl groups are e.g. methyl, ethyl, propyl, isopropyl, η-butyl, isobutyl, sec-butyl or tert-butyl;

2o C-j _ ^ alkoxy groups result analogously from the above Alkyl groups;

C 1-6 cycloalkyl groups are, for example, cyclopropyl, -butyl, -pentyl or -hexyl;
C "2-4 alkenyl or alkynyl groups contain 2, 3 or 4

25 carbon atoms, with the double bond or triple bond can stand at any point, e.g. can be terminal;

Ar can be substituted by 1, 2, 3 or more of the substituents mentioned; in the case of phenyl or pyridine residues

these are, for example, in the o-, m- or p-position; in the case of phenoxyphenyl radicals, the phenoxy group is preferably present in p-position.

Claims (6)

P atentansprüche f td compounds of the general formula R R is a hydrogen atom, a C ₁ ^ alkyl, a C-_g cycloalkyl, a C ₂ ^ alkenyl, a C ₂ ^ alkynyl, the phenyl or benzyl radical; 15 Ar is phenyl, pyridyl, naphthyl or a quinoline nucleus; Phenoxyphenyl or pyridyloxyphenyl, these groups optionally being replaced by one or more substituents selected from halogen atoms, C _1- ^ alkyl groups, C _1- , alkoxy groups, or a nitro, cyano, trifluoromethyl, so acetoxy, acetamido and methoxycarbonyl group substituted could be. 2.- The compounds according to claim 1, characterized in that 1 2 2 net that R is a group OR and R is a hydrogen atom or is a methyl group. 3.- Process for the preparation of the compounds according to claims 1 2 1, in which R stands for a group OR and R is a hydrogen atom or a C _1- ^ alkyl group, characterized in that an alkali salt of the formula: Ar-Y ⁹ - M Φ (II) in which M® stands for a cation of an alkali metal and Ar and Y have the meaning given in claim 1, in an inert gas atmosphere in a polar solvent 35 and at temperatures between room temperature and the boiling point of the solvent with an ester of formula R.
X - CH - CH = CH - CH = CH - C - OR ² (III) 11th in which X stands for a chlorine, bromine or iodine atom; R ² denotes a C1-4 alkyl group and R denotes a hydrogen atom or a methyl group to form the compounds of formula (I), in which R ^{2 is} Ζ _{Λ L} alkyl, possibly '~ \ _Tr whereupon these compounds / by hydrolysis are converted into compounds of the formula (I) in which R represents a hydrogen atom.
10 4, - compounds of the general formula X - CH - CH = CH - CH = CH - C - OR ² (IV) Il in which 2 X stands for a chlorine, bromine or iodine atom and R a ^C 1_ 4 is an alkyl group. 5, - Herbicide, containing as active substance one or several compounds according to claim 1 in amounts between 1 to 99% by weight. 6.- Plant growth regulators containing as active substance one or more compounds according to claim 1.