2-chloro-ethyl phosphonic acid esters and plant growth regulating agents containing same as active ingredient

The present invention relates to new compounds of the general formula (I) ##STR1## wherein R stands for hydrogen, C.sub.1-8 straight or branched chained alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy-C.sub.1-2 alkyl, PA0 R.sup.1 stands for 2,3-dihydro-2,2-dimethyl-benzofuran-7-yl, 4-methyl-coumarin-7-yl, 2,2,4-trimethyl-(2H)-chromen-5-yl or 2,2,4-trimethyl-(2H)-chromen-7-yl and Me stands for a monovalent cation and represents the salt of the acid. The new compounds show plant growth regulating activity and can be used as active ingredient of plant growth regulators.

The present invention relates to 2-chloro-ethyl phosphonic acid esters of 
the general formula (I) 
##STR2## 
the preparation of said compounds as well as plant growth regulating 
agents containing as active ingredient the compounds of general formula 
(I). 
In Hungarian patent specification No. 160,618 esters of 2-chloro-ethyl 
phosphonic acid with pyrocatechol, 4-chloro-pyrocatechol, phenol, 
salicylic alcohol, salicylic acid, resorcinol and other alcanols are 
disclosed. The biological activity of the esters is demonstrated on 
tomatoe, on bean arts, on ananas and on cereals. 
In DD-PS No. 132,632 the alkoxy trichloromethyl esters of 2-halo-ethyl 
phosphonic acid are disclosed having plant growth regulating and desiccant 
activity. 
In U.S. Pat. No. 4,042,370 the cyanoalkyl, alkoxy-carbonyl-alkyl-alkinyl 
oxo and thio esters of 2-chloro-ethyl phosphonic acid are disclosed which 
are used for the treatment of rubber trees in order to increase latex 
crop. In J. Prakt. Chem. 1975 798-806 among others cyclic esters of 
2-chloro ethyl phosphonic acid are disclosed and in these esters on the 
carbon attached to the oxygen can be hydrogen, alkyl or a cycloalkylene 
group can be attached to the two oxygen atoms. 
The new 2-chloro-ethyl phosphonic derivatives can be characterised by the 
general formula (I) wherein 
R stands for hydrogen, C.sub.1-8 straight or branched chained alkyl, 
C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy-C.sub.1-2 alkyl or a monovalent 
cation, 
R.sup.1 stands for 2,3-dihydro-2,2-dimethyl-benzofuran-7-yl, 
4-methyl-coumarin-7-yl, 2,2,4-trimethyl-(2H)-chromen-5-yl or 
2,2,4-trimethyl-(2H)-chromen-7-yl, Me stands for a monovalent cation and 
represents the salt of the acid. 
The new compounds show a plant growth regulating activity. 
The compounds of the 2-chloro-ethyl-phosphonic acid esters can be prepared 
by reacting the corresponding benzofuran or coumarin or chromene 
derivative with 2-chloro-ethyl-phosphonic acid dichloride in the presence 
of an acid binding agent. When preparing the diesters the corresponding 
benzofuran, coumarin or chromene derivative and the alcanol are reacted in 
the presence of an acid binding agent, and the desired end-product is 
isolated by methods known per se. 
The salts of the 2-chloro-ethyl phosphonic acid esters can be prepared by 
reacting the diester without isolation with the corresponding metal 
hydroxide. 
From the active ingredients of the general formula (I) the usual 
compositions such as water-soluble concentrates, wetting agents, wettable 
powders, granules, emulsifyable concentrates, colloidal aqueous 
suspensions can be prepared. 
The plant growth regulating activity means an activity of the active 
ingredient on the physiological processes of the plant growth depending on 
the time of the use, on the development stage of the plant and on the used 
concentration. 
The compositions can be prepared by methods known per se such as admixing 
the active ingredients with carriers i.e. liquid solvents and/or solid 
carriers and optionally surfactants, such as emulsifying or dispersing 
agents can be used. 
The compositions contain 0.1-95% by mass active ingredient. The active 
ingredients are usually used in the form of compositions or they can be 
used in the form of solutions, emulsifyable concentrates, suspensions, 
wettable powders, dusting agents or granules by spraying or vapourization. 
The active ingredient concentrations can be varied within a wide range 
depending on the character of the used active ingredients.

The new active ingredients and the compositions prepared from the active 
ingredients are illustrated in the following Examples. 
EXAMPLE 1 
Preparation of 2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-monoester 
(Compound No. 1) 
To 70 ml. anhydrous benzene 16.42 g (0.1 mole) 
2,3-dihydro-2,2-dimethyl-7-hydroxy-benzofuran and as acid binding agent 
12.11 g. (0.1 mole) N,N-dimethyl-aniline are added whereafter 21.93 g. 
(0.12 mole) 2-chloro-ethyl-phosphonic acid dichloride are added dropwise 
to the reaction mixture at room temperature under stirring. The reaction 
mixture is then heated for 2 hours and the reaction is monitored by gas 
chromatographic analysis. 
When the reaction is completed the mixture is cooled and at 
20.degree.-30.degree. C. a solution of 5.6 g. (0.14 mole) sodium hydroxide 
in 30 ml. water is added dropwise and the mixture is heated for 2 hours. 
The reaction mixture is then cooled, the benzene layer is separated, dried 
above anhydrous sodium sulphate and benzene is distilled off in vacuo on a 
rotatory film evaporator. The residual yellowish, thick, oily substance is 
washed with hexane and its purity is checked by gas chromatography. 
n.sub.D.sup.25 =1.5225. 
2-Chloro-ethyl-phosphonic acid-O-(4'-methylcoumarin-7'-yl)-ester is 
similarly prepared but 2,3-dihydro-2,2-dimethyl-7-hydroxy-benzofuran was 
replaced by 4-methyl-umbelliferon as starting material. The obtained 
product is a thick gummy product, n.sub.D.sup.24 =1.5650. 
EXAMPLE 2 
Preparation of 2-chloro-ethyl-phosphonic acid 
O-methyl-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester 
(Compound No. 2) 
16.42 g. (0.1 mole) 2,3-dihydro-2,2-dimethyl-7-hydroxy-benzofuran, 12.11 g. 
(0.1 mole) dimethyl-7-hydroxy-benzofuran, 12.11 g. (0.1 mole) 
N,N-dimethylaniline and 21.93 g. (0.12 mole) 2-chloro-ethyl-phosphonic 
acid dichloride are reacted as disclosed in Example 1. 
To the cooled reaction mixture 3.52 g. (0.11 mole) methanol and 12.11 g. 
(0.1 mole) N,N-dimethyl-aniline are added dropwise. The reaction mixture 
is then heated for 2 hours. The reaction is then monitored by gas 
chromatographic analysis. After cooling the reaction mixture the 
precipitated N,N-dimethyl-aniline-hydrochloride is filtered and the 
benzene solution is washed with diluted hydrochloric acid solution with 
aqueous sodium hydroxide solution and then with water. It is dried above 
anhydrous sodium sulphate and the solvent is distilled off in vacuo on a 
rotatory film evaporator. 
Thus 15.76 g. orange, thick, oily liquid substance are obtained, 
n.sub.D.sup.25 =1.5180. 
By using the reaction components of the following table compounds 3-10 can 
be prepared by the process disclosed in Examples 1 and 2. 
__________________________________________________________________________ 
Number 
Reaction component 
Compound of the general 
of the 
aliphatic 
heterocyclic 
formula (I) 
compound 
alcohol 
phenol R R.sup.1 end product 
__________________________________________________________________________ 
3 2-chloro- ethanol 
2,3-dihydro- 2,2-dimethyl- 7-hydroxy- benzofuran 
ClCH.sub.2CH.sub.2 
##STR3## 2-chloro-ethyl- phosphonic 
acid- Omethyl-O(2,3- 
dihydro-2,2-di- methyl-benz 
ofuran- 7-yl)-ester 
4 n-octyl- alcohol 
2,3-dihydro- 2,2-dimethyl- 7-hydroxy- benzofuran 
C.sub.8 H.sub.17 
##STR4## 2-chloro-ethyl- phosphonic 
acid-O(2- chloro-ethyl)- 
O(2,3-dihydro-2,2- 
dimethyl-benzofuran- 
7-yl)ester 
5 2-butoxy- ethanol 
2,3-dihydro- 2,2-dimethyl- 7-hydroxy- benzofuran 
C.sub.4 H.sub.9O CH.sub.2CH.sub.2 
##STR5## 2-chloro-ethyl- phosphonic 
acid-O(2- butoxy-ethyl)-O(2 
,3- dihydroxy-2,2- 
dimethyl-benzofuran- 
7-yl)-ester 
6 sec.butanol 
2,3-dihydro- 2,2-dimethyl- 7-hydroxy- benzofuran 
##STR6## 
##STR7## 2-chloro-ethyl- phosphonic 
acid-O(2- methyl-propyl)- 
O2,3-dihydro-2,2- dimethyl- 
benzofuran- 7-yl)-ester 
7 -- 4-methyl-um- belliferon 
H 
##STR8## 2-chloro-ethyl- phosphonic 
acid-O(4- methyl-coumarin- 
-yl)-ester 
8 methanol 
4-methyl-um- belliferon 
CH.sub.3 
##STR9## 2-chloro-ethyl- phosphonic 
acid-O methyl-O(4-methyl- 
coumarin-7-yl)-ester 
9 methanol 
2,2,4-trimethyl- (2H)5-hydroxy- chromene 
CH.sub.3 
##STR10## 2-chloro-ethyl- phosphonic 
acid- Omethyl-(2,2,4- 
trimethyl-(2H) chromene-5-y 
l)-ester 
10 methanol 
2,2,4-trimethyl- (2H)7-hydroxy- chromene 
CH.sub.3 
##STR11## 2-chloro-ethyl- phosphonic 
acid- Omethyl-O(2,2,4- 
trimethyl- (2H)chromene-7- 
l)-ester 
__________________________________________________________________________ 
EXAMPLE 3 
Emulsifiable concentrate can be prepared from the following components: 
______________________________________ 
Compound No. 2 10% by mass 
mixture of polyoxyethylene- 
5% by mass 
alkyl-aryl-ether and alkyl- 
phenol alkoxalate 
(Emulsogen I-40, manufactured by 
Hoechst) 
toluene 85% by mass 
100% by mass 
______________________________________ 
EXAMPLE 4 
Emulsifiable concentrate: 
______________________________________ 
Compound No. 3 70% by mass 
.alpha.-[4-(1,1,3,3-tetramethyl-butyl)- 
10% by mass 
phenyl]-.omega.-hydroxy-poly(oxy-1,2- 
ethandiyl) (Triton X-100) 
isophoron 20% by mass 
100% by mass 
______________________________________ 
EXAMPLE 5 
Wettable powder 
______________________________________ 
Compound No. 8 20% by mass 
sodium-oleyl-methyl-tauride 
7% by mass 
(Arkopon T-Hoechst) 
sodium-lignin-sulphonate 
5% by mass 
colloidal synthetic silicon dioxyde 
28% by mass 
kaolin 40% by mass 
100% by mass 
______________________________________ 
EXAMPLE 6 
Dusting agent 
______________________________________ 
Compound No. 2 1% by mass 
talc 99% by mass 
100% by mass 
______________________________________ 
EXAMPLE 7 
Colloidal aqueous suspension concentrate 
______________________________________ 
Compound No. 10 30% by mass 
mixture of polyoxyethylene-mono- 
6% by mass 
laurate and alkylphenol-alkoxalates 
(Emulsogen IC-HOECHST) 
magnesium-lignin-sulphonate 
4% by mass 
lecithine 4% by mass 
colloidal synthetic silicon dioxide 
26% by mass 
water 30% by mass 
100% by mass 
______________________________________ 
EXAMPLE 8 
Granule 
______________________________________ 
Compound No. 4 5% by mass 
kaolin 95% by mass 
100% by mass 
______________________________________ 
EXAMPLE 9 
Emulsifiable concentrate 
______________________________________ 
Compound No. 1 85% by mass 
polyoxyethylene-sorbitan-monolaurate 
10% by mass 
(Tween-20, Atlas) 
methylene-chloride 5% by mass 
100% by mass 
______________________________________ 
EXAMPLE 10 
Water soluble concentrate 
______________________________________ 
Compound No. 12 10% by mass 
polyoxyethylene-sorbitan-monolaurate 
8% by mass 
(Tween-20, Atlas) 
water 82% by mass 
100% by mass 
______________________________________ 
EXAMPLE 11 
Dusting agent 
______________________________________ 
Compound No. 15 1% by mass 
talc 99% by mass 
100% by mass 
______________________________________ 
EXAMPLE 12 
Wettable powder 
______________________________________ 
Compound No. 18 70% by mass 
fatty alcohol sulphonate 
6% by mass 
sodium-lignin-sulphonate 
4% by mass 
colloidal synthetic silicon dioxide 
16% by mass 
kaolin 4% by mass 
100% by mass 
______________________________________ 
EXAMPLE 13 
Granule 
______________________________________ 
Compound No. 14 5% by mass 
vermiculite 95% by mass 
100% by mass 
______________________________________ 
Biological tests 
2-Chloroethyl-phosphonic acid esters and salts thereof according to the 
invention were tested on plant growth regulating activity in green house 
by using tomato, soya beans and sunflower as indicating plants. The plants 
were seeded into pots filled with turf or the plants were set as 
seedlings. The post-emergent treatment was carried out on tomato at a 
development stage of 20-30 cm. and on soybeans and sunflower at a 
development stage of 10-20 cm. In the course of the tests a control 
without active ingredient (K) was always used and as active ingredient 
2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester (Compound 
No. 2) and as referential compounds 2-chloro-ethyl-phophonic acid (F) and 
2,2-dimethyl-2,3-dihydro-7-hydroxy-benzofuran (G) were used. In the tomato 
indicating plant pre-emergent treatment was also carried out. The used 
doses and the obtained results are summarized in the tables. 
When evaluating the biological tests the change of the height of plants was 
determined. The height change in the case of tomato treated post-emergence 
was determined on the 4., 7. and 10. day after the treatment, in soybeans 
and sunflower on the 7th day after the treatment and in case of the 
treatment pre-emergence, the plant's height was also determined on the 7th 
day after treatment. 
The results are given in the percent of the starting height. 
TABLE I 
______________________________________ 
Effect of post-emergent treatment on the growth of tomato 
Treatment 
Change in the % of the 
dose starting height 
Composition 
kg./ha. 4. day 7. day 10. day 
______________________________________ 
K 29 53 71 
Compound 2 0.5 47 81 101 
1.0 47 77 100 
2.0 41 71 85 
F 0.5 42 69 86 
1.0 41 68 76 
2.0 43 65 70 
G 0.5 31 63 78 
1.0 37 62 80 
2.0 38 70 83 
______________________________________ 
The table shows that 2-chloro-ethyl-phosphonic 
acid-O-methyl-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester increase 
the height of tomato at a great extent related to the untreated control. 
The increase of the height was in inverse ratio to the increase of the 
dose. At a rate of 2 kg./ha. its activity was the same as that of 
2-kg./ha. 2,2-dimethyl-2,3-dihydro-7-hydroxy-benzofuran and that of 0.5 
kg./ha. of 2-chloro-ethyl-phosphonic acid. 
TABLE 2 
______________________________________ 
Effect of post-emergent treatment on the growth of soybeans 
Change in the % of the starting 
Treatment 
height 
dose I. II. III. IV. V. -- 
Composition 
kg./ha. rep. rep. rep. rep. rep. X 
______________________________________ 
K 23.4 26.9 21.1 25.1 26.2 24.5 
Comp. 2 0.5 17.1 24.5 29.0 25.8 23.1 23.4 
1.0 14.9 24.5 24.0 23.1 17.1 20.7 
2.0 16.0 13.3 18.6 18.0 14.5 16.1 
F 0.5 13.0 11.3 14.1 15.1 9.4 12.6 
1.0 15.1 10.6 12.4 11.4 11.4 12.2 
2.0 6.6 10.0 8.5 9.5 8.8 8.7 
G 0.5 33.8 28.2 32.6 37.6 33.3 33.1 
1.0 22.6 30.4 35.8 22.1 33.8 28.9 
2.0 23.8 18.4 20.5 20.6 19.5 20.6 
______________________________________ 
rep. = repetition 
The table shows that as opposed to the results on tomato a higher rate of 
(1.0, 2.0 kg./ha.) 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester had a 
result of decreasing the height of soybeans. The extent of this decrease 
was lower than the values measured at similar rates of 
2-chloro-ethyl-phosphonic acid. When using 
2,2-dimethyl-2,3-dihydro-7-hydroxy-benzofuran alone the doses of 0.5 and 
1.0 kg./ha intensively increased whereas the dose of 2 kg./ha. slightly 
decreased the growth. 
TABLE 3 
______________________________________ 
Effect of post-emergent treatment on the growth of sunflower 
Change in the % of the starting 
Treatment 
height 
dose I. II. III. IV. V. 
Composition 
kg./ha. rep. rep. rep. rep. rep. .sup.--X 
______________________________________ 
K 33.0 38.8 31.1 27.9 26.7 31.5 
Compound 1.0 24.3 22.2 24.2 28.4 29.6 25.7 
2 2.0 21.2 17.0 20.0 20.5 21.5 20.0 
F 1.0 6.3 5.0 6.1 5.4 6.2 5.8 
2.0 5.8 5.1 5.0 4.0 2.7 4.5 
G 1.0 27.8 25.0 38.9 33.3 26.5 30.3 
2.0 32.9 35.0 35.3 30.1 30.2 32.7 
G + F 0.5 + 0.5 18.9 17.4 17.3 23.5 20.5 19.5 
0.5 + 1.0 10.6 10.4 10.7 10.7 10.8 10.6 
1.0 + 0.5 20.2 25.5 21.3 15.7 23.6 21.3 
1.0 + 1.0 10.1 8.5 10.3 11.8 14.2 11.0 
______________________________________ 
rep. = repetition 
Compared to the untreated control 1 kg./ha. of 2-chloroethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester decreased 
the growth of sunflower by 1/6 and the dose of 2.0 kg./ha. decreased its 
height by approximately 1/3. As a result of similar doses of 
2-chloro-ethyl-phosphonic acid the height growth amounted only to 1/6 of 
the value of the control. 
2,2-Dimethyl-2,3-dihydro-7-hydroxy-benzofuran did not significantly 
influence the growth. 
When using 2-chloro-ethyl-phosphonic acid and 
2,2-dimethyl-(2,3-dihydro-7-hydroxy)-benzofuran in a mixture of various 
active ingredient ratios the depressant activity of 
2-chloro-ethyl-phosphonic acid decreased. It further shows that by using 
an 1:1 mixture of the two compounds the depressant activity of 
2-chloro-ethyl-phosphonic acid somewhat decreased. 
TABLE 4 
______________________________________ 
Effect of pre-emergent treatment on the growth of tomato 
Change in the % of the starting 
Treatment 
height 
dose I. II. III. IV. 
Composition 
kg./ha. rep. rep. rep. rep. .sup.--X 
______________________________________ 
K 28.4 31.3 27.5 26.1 28.3 
Compound 1.0 28.6 29.5 30.7 31.6 30.1 
2 2.0 35.2 33.1 30.8 32.6 32.9 
4.0 26.2 24.5 26.3 25.2 25.6 
8.0 20.8 17.6 18.9 17.1 18.6 
F 2.0 27.5 26.9 33.1 28.2 28.9 
G 2.0 33.1 32.6 29.8 32.9 32.1 
______________________________________ 
rep.: repetition 
When testing the activity of the compositions through the soil it can be 
observed that when spraying 2-chloro-ethyl-phosphonic acid on the soil no 
plant growth regulating activity is exhibited. A rate of 2 kg./ha. of 
2,2-dimethyl-2,3-dihydro-7-hydroxy-benzofuran stimulated the growth 
similarly to 1 and 2 kg./ha. resp. of 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester. The 
growth of tomato at a rate of 4 kg./ha. is moderate whereas at a rate of 8 
kg./ha. the growth was reduced by 1/3. 
In green house tests in culture dishes the plant growth regulating activity 
of 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethylbenzofuran-7-yl)-ester was tested 
pre-emergence and post-emergence by using tomato, soybeans and sunflowers 
as test plants. 
The height of tomato was increased by using 2-chloro-ethyl-phosphonic 
acid-O-methyl-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester, the extent 
of the growth was in inverse ratio to the dose. The activity of the active 
ingredient depends on the tested arts and on the development stage of the 
plants. The height of the soybeans and the sunflowers was reduced by the 
doses used on tomato proportionally with the amount of the active 
ingredient used pro hectare. 
2-Chloro-ethyl-phosphonic 
acid-O-methyl-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester as 
opposed to 2-chloro-ethyl-phosphonic acid when treated pre-emergence in 
tomato can act as plant growth regulator by being absorbed from the soil 
through the route. 
The biological tests were repeated under the disclosed test conditions on 
the mentioned plants. As active ingredient 2-chloro-ethyl-phosphonic 
acid-O-methyl-(4-methyl-coumarin-7-yl)-ester (Compound No. 7) and as 
referential compounds 2-chloro-ethyl-phosphonic acid (F) and 
7-hydroxy-4-methyl-coumarin (M) were used next to the control (K). 
TABLE 5 
______________________________________ 
Effect of post-emergence treatment on the growth of tomato 
Treatment 
Change in the % of the start- 
dose ing height 
Composition 
kg./ha. 4. day 7. day 
10. day 
______________________________________ 
K 29 53 71 
Compound 0.5 38 73 90 
No. 7 1.0 44 81 95 
2.0 40 66 83 
F 0.5 42 69 86 
1.0 41 68 76 
2.0 43 65 70 
M 0.5 33 60 72 
1.0 35 64 78 
2.0 37 70 82 
______________________________________ 
The results of Table 5 show that 2-chloro-ethyl-phosphonic 
acid-O-methyl-(4'-methyl-coumarin-7'-yl)-ester significantly increased the 
growth of the tomato related to the untreated control. The activity can be 
characterized as a function of the dose by a curve of second order the 
peak of which is at the dose of 1 kg./ha. By further increasing the dose 
the composition already shows mainly a growth inhibiting activity. It can 
be seen further that the growth stimulating activity is more intensive 
than that of 7-hydroxy-4-methyl-coumarin and at higher doses the growth 
inhibiting activity is lower than that of 2-chloro-ethyl-phosphonic acid. 
TABLE 6 
______________________________________ 
Effect of post-emergent treatments on the growth of soybeans 
Treat- 
ment 
dose Change in the % of starting height 
Composition 
kg./ha. I. II. III. IV. V. Average 
______________________________________ 
K 23.4 26.9 21.1 25.1 26.2 24.5 
Compound 0.5 18.2 22.4 26.0 22.4 23.6 22.5 
No. 7 1.0 19.3 21.1 22.6 20.8 21.2 21.0 
2.0 15.4 13.2 15.7 16.0 15.1 15.1 
F 0.5 13.0 11.3 14.1 15.1 9.4 12.6 
1.0 15.1 10.6 12.4 11.4 11.4 12.2 
2.0 6.6 10.0 8.5 9.5 8.8 8.7 
M 0.5 30.7 31.0 31.5 33.2 35.4 32.4 
1.0 24.2 30.1 30.2 24.1 29.8 27.7 
2.0 21.9 19.0 20.0 20.2 18.7 20.0 
______________________________________ 
When using 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester in soybeans all the three 
tested doses reduced the height of soybeans differently from the results 
observed on tomato. The extent of the reduction of the height was lower 
than the values measured for 2-chloro-ethyl-phosphonic acid with similar 
rates. 0.5 kg./ha. of 7-hydroxy-4-methyl-coumarin stimulated whereas 2 
kg./ha. of the same coumpound inhibited the growth. 
TABLE 7 
______________________________________ 
Effect of post-emergent treatments on the growth of sunflower 
Treat- 
ment Change in the % of starting the 
Compo- dose height 
sition kg./ha. I. II. III. IV.. V. Average 
______________________________________ 
K 33.0 38.8 31.1 27.9 26.7 31.5 
Compound 
1.0 22.1 20.8 23.0 24.1 23.7 22.7 
No. 7 2.0 19.3 17.6 20.1 18.9 21.1 19.4 
F 1.0 6.3 5.0 6.1 5.4 6.2 5.8 
2.0 5.8 5.1 5.0 4.0 2.7 4.5 
M 1.0 31.3 34.6 29.8 30.5 32.4 31.7 
M 2.0 27.4 28.2 27.5 26.9 28.1 27.6 
M + F 0.5 + 0.5 
20.3 19.8 21.0 19.5 20.4 20.2 
1.0 + 0.5 
9.9 10.4 9.2 9.5 10.0 9.8 
0.5 + 1.0 
21.4 25.0 22.0 21.3 24.2 22.8 
1.0 + 1.0 
9.5 9.1 10.6 10.2 11.4 10.2 
______________________________________ 
When compared with the untreated control 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(4-methyl-coumarin-7-yl)-ester reduced the growth of 
sunflower at both of the tested doses. The plant growth was intensively 
inhibited by 2-chloro-ethyl-phosphonic acid whereas 1 kg./ha. of 
7-hydroxy-4-methyl-coumarin did not effect the growth of sunflower and 2 
kg./ha. of the same compound slightly inhibited its growth. A mixture of 
2-chloro-ethyl-phosphonic acid and 7-hydroxy-4-methyl-coumarin at various 
active ingredient's ratios it could be observed that the depressant 
activity of 2-chloro-ethyl-phosphonic acid was moderated by the 
7-hydroxy-4-methyl-coumarin. 
TABLE 8 
______________________________________ 
Effect of pre-emergent treatment on the growth of tomato 
Treatment 
Change in the % of 
dose the starting height 
Composition 
kg./ha. I. II. III. IV. Average 
______________________________________ 
K 28.4 31.3 27.5 26.1 28.3 
Compound 1.0 32.1 33.6 30.8 31.5 32.0 
No. 7 2.0 35.8 36.1 33.4 34.1 34.9 
4.0 27.2 25.1 25.8 24.7 25.2 
8.0 17.4 19.2 17.6 17.0 17.8 
F 2.0 27.5 26.9 33.1 28.2 28.9 
M 2.0 30.1 34.6 30.8 32.9 32.1 
______________________________________ 
When evaluating the activity of the compositions through the soil it shows 
that 2-chloro-ethyl-phosphonic acid does not act as plant growth regulator 
through the roots. 
2kg./ha. of 7-hydroxy-4-methyl-coumarin stimulated the growth similarly to 
1 and 2 kg./ha. of 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(4-methyl-coumarin-7-yl)-ester. By increasing the dose pro 
hectare to 4 and 8 kg./ha. the growth of tomato was already moderated. 
When spraying 2-chloro-methyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7-yl)-ester on the foliage the height 
of tomato was increased. The growth of soybeans and sunflowers at the 
tested doses was reduced by the active ingredient. 
When treating tomato pre-emergence 2-chloro-ethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester was sprayed on the soil 
and the active ingredient penetrated through the root of the plants and 
acted as plant growth regulator which could be observed in the change of 
the height of tomato. 
Under the given test conditions further biological tests were carried out 
on the mentioned test plants. As active ingredient 
2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester and as referential 
compounds 2-chloro-ethyl-phosphonic acids (F) and 
2,3-dihydro-2,2-dimethyl-7-hydroxy-benzofuran (N) were used next to the 
control (K). 
TABLE 9 
______________________________________ 
Effect of post-emergent treatments on the growth of soybeans 
Treatment Change in the % of the starting 
Compo- dose height 
sition kg./ha. I. II. III. IV. V. Average 
______________________________________ 
K 23.4 26.9 21.1 25.1 26.2 24.5 
Comp. 0.5 14.9 15.1 13.6 14.8 14.1 14.5 
No. 1 1.0 13.7 14.0 14.6 14.1 13.8 14.0 
2.0 13.1 13.5 12.9 13.6 13.0 13.2 
F 0.5 13.0 11.3 14.1 15.1 9.4 12.6 
1.0 15.1 10.6 12.4 11.4 11.4 12.2 
2.0 6.6 10.0 8.5 9.5 8.8 8.7 
N 0.5 33.8 28.2 32.6 37.6 33.3 33.1 
1.0 22.6 30.4 35.8 22.1 33.8 28.9 
2.0 23.8 18.4 20.5 20.6 19.5 20.6 
______________________________________ 
After the evaluation of the biological activity of 
2-chloro-ethyl-phosphonic acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl 
)-ester it shows that the soybeans' growth is influenced by the compound. 
In the tested period the height of the untreated plants increased on an 
average by 24.5% whereas the height of the plants treated by various doses 
of 2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester by 13%. 
TABLE 10 
______________________________________ 
Effect of post-emergent treatment on the growth of sunflower 
Treatment Change in the % of the starting 
Compo- dose height 
sition kg./ha. I. II. III. IV. V. Average 
______________________________________ 
K 33.0 38.8 31.1 27.9 26.7 31.5 
Comp. 1.0 8.7 10.3 9.4 9.7 10.0 9.6 
No. 1 2.0 7.5 6.6 8.0 6.4 7.0 7.1 
F 1.0 6.3 5.0 6.1 5.4 6.2 5.8 
2.0 5.8 5.1 5.0 4.0 2.7 4.5 
N 1.0 27.8 25.0 38.9 33.3 26.5 30.3 
2.0 32.9 35.0 35.3 30.1 30.2 32.7 
N + F 0.5 + 0.5 18.9 17.4 17.3 23.5 20.5 19.5 
0.5 + 1.0 10.6 10.4 10.7 10.7 10.8 10.6 
1.0 + 0.5 20.2 25.5 21.3 15.7 23.6 21.3 
1.0 + 1.0 10.1 8.5 10.3 11.8 14.2 11.0 
______________________________________ 
The growth of sunflower was significantly reduced by 
2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester when comparing 
with the untreated control. During the test period the height of the 
untreated control was increased by 31.5% related to the starting value 
whereas the height of the plants treated with the compound according to 
the invention was increased only by 9.6-7.1%. The compounds were used in 
combinations of various ratios thus 2-chloro-ethyl phosphonic acid and 
2,3-dihydro-2,2-dimethyl-7-hydroxy-benzofuran were used at rates of 1 
kg./ha.+0.5 kg./ha. and 1 kg./ha.+1 kg./ha. and none of these combinations 
achieved the plant growth regulating activity of the compound according to 
the invention. 
TABLE 11 
______________________________________ 
Effect of pre-emergent treatments on the growth of tomato 
Treatment 
Change in the % of the starting 
dose height 
Composition 
kg./ha. I. II. III. IV. Average 
______________________________________ 
K 28.4 31.3 27.5 26.1 28.3 
Compound 1.0 38.6 40.2 37.9 38.3 38.8 
No. 1 2.0 43.2 41.8 42.0 39.6 41.2 
4.0 41.7 44.6 43.9 42.7 43.2 
8.0 21.4 19.6 24.3 20.5 21.5 
F 2.0 27.5 26.9 33.1 28.2 28.9 
N 2.0 33.1 32.6 29.8 32.9 32.1 
______________________________________ 
2-Chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester was used 
pre-emergence and when evaluating the biological activity of the compound 
an intensive plant growth stimulating activity can be seen on tomato 
showing the composition was absorbed by the plant from the soil. The 
growth of the untreated control was in the tested period 28.3% related to 
the starting height. The growth of the plants treated with 1-4 kg./ha. of 
2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester was 38.8-43.2%. By 
increasing the dose of the composition to 8 kg./ha. the growth stimulation 
turned over to growth inhibition. The test results can be summarized as 
follows: 
By spraying 2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester on soybeans and 
sunflower a significant growth inhibition could be observed related to the 
untreated control. On the basis of the growth inhibition it can be said 
that 2-chloro-ethyl-phosphonic acid-(2,3-dimethyl-benzofuran-7-yl)-ester 
regulates the plant growth when used post-emergence. In case of a 
treatment pre-emergence the plant growth regulating activity of 
2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester can be similarly 
observed as proved by the tests carried out e.g. on tomatoe. 
The post-emergent activity of the compositions according to the invention 
was also tested in free land tests on soybeans, maize, winter wheat and 
red pepper. The results of the test are shown in the following tables. 
SOYBEANS 
Test conditions 
Type of soil: field chernozem 
Green-crop: sugar beet 
Fertilization: 
50 kg./ha. N(ammonium-nitrate) 
100 kg./ha. P.sub.2 O.sub.5 (superphosphate of 18%) 
120 kg./ha. K.sub.2 O (potassium chloride of 50%) 
Weed killing: 910 g./ha. 
2,6-dinitro-N,N-dipropyl-4-trifluoro-methyl-aniline+900 g./ha. 
N-(4-bromo-3-chloro-phenyl)-N'-methoxy-N'-methyl-urea 
Art: ISz-15 
Stock-number: 350,000 stock/ha. 
Parcel size: 2.times.10 m. 
Repetitions: 6 
Spray liquid: 200 l./ha. 
Treatments: 
(1) untreated control 
(2) 2-chloroethyl-phosphonic acid: 250 g./ha. 
(3) 2-chloroethyl-phosphonic acid: 500 g./ha. 
(4) 2-chloroethyl-phosphonic acid: 1000 g./ha. 
(5) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 250 g./ha. 
(6) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 500 g./ha. 
(7) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 1000 g./ha. 
(8) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)ester: 250 g./ha. 
(9) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 500 g./ha. 
(10) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 1000 g./ha. 
The spraying was carried out at the beginning of the budding of the 
soybeans. The spray liquid concentration changed in the range of 1.13 
g./l. to 4.54 g./l. related to the active ingredient. 
Compositions disclosed in Examples 3 and 8 were used. 
TABLE 12 
______________________________________ 
Effect of post-emergent treatment on soybeans' crop 
Change in the 
Number of Dose Crop average 
% of the 
treament g./ha. t./ha. control 
______________________________________ 
1. -- 2.60 100 
2 250 2.68 103 
3 500 2.32 89 
4 1000 2.05 79 
5 250 3.00 115 
6 500 2.90 111 
7 1000 2.74 105 
8 250 2.98 115 
9 500 3.00 115 
10 1000 2.82 108 
______________________________________ 
The results show that the compounds according to the invention increased 
the crop as opposed to 2-chloro-ethyl-phosphonic acid. 
A 15% crop increase was measured at a rate of 250 g./ha. 
2-chloro-ethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester and 
2-chloro-ethyl-phosphonic acid-O-methyl-O-(4-methyl-coumarin-7-yl)-ester. 
By increasing the dose to 1000 g./ha. the crop increase amounted only to 
5-8%, the crop, however, was reduced to 21% by the same dose of 
2-chloro-ethyl-phosphonic acid. 
WINTER WHEAT 
Test conditions 
Type of soil: field chernozem 
Green-crop: green peas 
Fertilization: 
200 kg./ha. N(ammonium-nitrate) 
120 kg./ha. P.sub.2 O.sub.5 (superphosphate of 18%) 
140 kg./ha. K.sub.2 O (potassium chloride of 50%) 
Weed killing: 1000 g./ha. ammonium salt of 2,4-dichloro-phenoxy-acetic acid 
Art: Mv-80 
Stock number: 5.5 million stock/ha. 
Parcel size: 2.times.10 m. 
Repetitions: 6 
Spray liquid: 220 l./ha. 
Treatments: 
(1) untreated control 
(2) 2-chloroethyl-phosphonic acid: 500 g./ha. 
(3) 2-chloroethyl-phosphonic acid: 1000 g./ha. 
(4) 2-chloroethyl-phosphonic acid: 2000 g./ha. 
(5) 
2-chloroethyl-phosphonicaacid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl) 
-ester: 500 g./ha. 
(6) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 1000 g./ha. 
(7) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 2000 g./ha. 
(8) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 500 g./ha. 
(9) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)ester: 1000 g./ha. 
(10) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 2000 g./ha. 
(11) 2-chloroethyl-phosphonic acid: 50 g./ha. 
(12) 2-chloroethyl-phosphonic acid: 100 g./ha. 
(13) 2-chloroethyl-phosphonic acid: 200 g./ha. 
(14) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 50 g./ha. 
(15) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 100 g./ha. 
(16) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 200 g./ha. 
(17) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 50 g./ha. 
(18) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 100 g./ha. 
(19) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 200 g./ha. 
Treatments number 2 to 10 were performed when growing into thick and 
treatments 11-19 were performed during earing. The spray liquid 
concentration changed in the range of 0.22 g./l. to 9.1 g./l. related to 
the active ingredient. Compositions disclosed in Examples 3 and 8 were 
used. 
TABLE 13 
______________________________________ 
Effect of post-emergent treatments on the crop of winter wheat 
Change in the 
Number of Dose Crop average 
% of the 
treatment g./ha. t./ha. control 
______________________________________ 
1 -- 7.75 100 
2 500 7.82 101 
3 1000 7.53 97 
4 2000 6.79 87 
5 500 8.66 112 
6 1000 8.51 110 
7 2000 8.46 109 
8 500 8.80 114 
9 1000 8.97 116 
10 2000 8.88 115 
11 50 7.74 100 
12 100 7.88 102 
13 200 7.44 96 
14 50 7.91 102 
15 100 8.38 108 
16 200 8.17 105 
17 50 7.86 101 
18 100 8.30 107 
19 200 8.53 110 
______________________________________ 
The data of the results performed on winter wheat show that when spraying 
the compositions according to the invention when growing into thick the 
crop was increased at the tested ratios by more than 10%. The crop was not 
influenced by 2-chloro-ethyl-phosphonic acid or it was reduced by higher 
rates of the same compound. When using the compositions according to the 
invention during the earing and 5-10% crop increase was measured at rates 
of 100-200 g./ha. At the same time 2-chloro-ethyl-phosphonic acid was 
applied and substantially no change in the crop could be observed. 
MAIZE 
Test conditions 
Soil type: field chernozem 
Green-crop: winter wheat 
Fertilization: 
250 kg./ha. N(ammonium-nitrate) 
140 kg./ha. P.sub.2 O.sub.5 (18% superphosphate) 
180 kg./ha. K.sub.2 O (50% potassium chloride) 
Weed killing: 2000 g./ha. 
N-(ethoxy-methyl)-2-ethyl-6-methyl-chloro-acetanilide+1000 g./ha. 
N-(4-bromo-3-chloro-phenyl)-N'-methoxy-N'-methyl-urea 
Art: Pioneer 3709 
Stock number: 82,000 stock/ha. 
Parcel size: 2.1.times.10 m. 
Repetition: 6 
Spray liquid: 220 l./ha. 
Treatments: 
(1) Untreated control 
(2) 2-chloroethyl-phosphonic acid: 500 g./ha. 
(3) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 250 g./ha. 
(4) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 500 g./ha. 
(5) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 1000 g./ha. 
(6) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 250 g./ha. 
(7) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 500 g./ha. 
(8) 2-chloroethyl-phosphonic 
acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester: 1000 g./ha. 
The treatments were performed at the stage of 6-8 leaves, the spray liquid 
concentration was in the range of 1.13 g./l. to 4.54 g./l. related to the 
active ingredient. Compositions disclosed in Examples 3 and 8 were used. 
TABLE 14 
______________________________________ 
Effect of post-emergent treatment on the crop of maize 
Number of 
Dose Crop average 
Change in the % of 
treatment 
g./ha. t./ha. the control 
______________________________________ 
1 -- 7.12 100 
2 500 5.68 80 
3 250 8.30 117 
4 500 7.94 112 
5 1000 6.97 98 
6 250 8.56 120 
7 500 8.03 113 
8 1000 7.21 101 
______________________________________ 
2-Chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester and 
2-chloro-ethyl-phosphonic acid-O-methyl-O-(4'-methyl-coumarin-7'-yl)-ester 
were tested on maize and the crop was increased by 17-20% at a rate of 250 
g./ha. By increasing the dose the crop increase was reduced and at a rate 
of 1000 g./ha. there was no more difference related to the untreated 
control. As opposed to the compounds according to the invention 500 g./ha. 
of 2-chloro-ethyl-phosphonic acid reduced the crop by 20%. 
RED PEPPER 
Test conditions 
Soil type: field chernozem 
Green crop: onion 
Fertilization: 40 t./ha. organic fertilizer 
Weed killing: 910 g./ha. 
2,6-dinitro-N,N-dipropyl-4-trifluoro-methyl-aniline+manual hoeing 
Art: Szegedi spicy F 03 red pepper 
Stock number: 365,000 stock/ha. 
Parcel size: 2.times.10 m. 
Repetition: 6 
Spray liquid: 220 l./ha. 
Treatments: 
(1) Untreated control 
(2) 2-chloroethyl-phosphonic acid: 1000 g./ha. 
(3) 2-chloroethyl-phosphonic 
acid-O-(2,3-dihydro-2,2-dimethyl-benzofuran-7-yl)-ester: 1000 g./ha. 
(4) 2-chloroethyl-phosphonic 
acid-O-methyl-(4'-methyl-coumarin-7'-yl)-ester: 1000 g./ha. 
The spraying was performed at the beginning of the colourization of the 
pepper. The spray liquid concentration amounted to 4.54 g./l, related to 
the active ingredient. Compositions disclosed in Examples 3 and 8 were 
used. 
TABLE 15 
__________________________________________________________________________ 
Effect of post-emergent treatment on the crop and qualitative parameters 
of red pepper 
Composition, Ratio of The colour distribution of ripe 
number of 
Crop green peppers % 
treatment 
t./h. 
% peppers % 
Dye % 
completely ripe 
semi-ripe 
worthless 
__________________________________________________________________________ 
1 3.15 
100 
28 8.84 
42.5 22.6 43.8 
2 2.85 
90 
25 10.07 
51.2 28.4 20.4 
3 3.55 
113 
20 9.98 
70.1 11.4 18.5 
4 3.60 
114 
20 9.65 
72.3 9.7 18.0 
__________________________________________________________________________ 
According to the test results carried out on red pepper the compounds 
according to the invention increased the crop by 13-14% whereas the 
treatment with 2-chloro-ethyl-phosphonic acid reduced the crop. The ratio 
of completely green peppers was also less. The amount of colouring 
substances was increased related to the untreated control but did not 
achieve the value measured for 2-chloro-ethyl-phosphonic acid. 
When testing the coloured peppers it shows that the ratio of the completely 
ripe peppers giving the best quality achieved 70% on parcels treated with 
the compounds according to the invention. The ratio of semi-ripe and brown 
worthless peppers was significantly lower than in case of the untreated 
control or on parcels treated with 2-chloro-ethyl-phosphonic acid.