Trifluoromethyl-phenoxy-phenyl-silicon derivatives, processes for their preparation, and their use as herbicides and plant-growth regulators

A trifluoromethyl-phenoxy-phenyl-silicon compound is disclosed of the general formula ##STR1## in which X.sup.1 and X.sup.2 independently of each other represent a hydrogen, fluorine, chlorine, bromine or iodine atom, PA1 Y represents a hydrogen or halogen atom or a cyano or nitro group, PA1 n is 0 or 1, PA1 m is 0, 1, 2 or 3, PA1 p is 0, 1, 2 or 3, PA1 X.sup.3 and X.sup.4 independently of each other represent oxygen or a --CO--O-- group, PA1 R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another represent a hydrogen atom or a C.sub.1 to C.sub.5 alkyl group, PA1 R.sup.5 and R.sup.6 independently of each other represent a C.sub.1 to C.sub.5 alkyl group, and PA1 R.sup.7 represents a C.sub.1 to C.sub.5 alkyl or hydroxyl group, a chlorine, bromine, or iodine atom or a C.sub.2 to C.sub.5 alkenoxy, C.sub.2 to C.sub.5 alkinoxy, PA1 C.sub.1 to C.sub.5 alkylthio, C.sub.2 to C.sub.5 alkenyl-thio or C.sub.2 to C.sub.5 alkinyl-thio group or a C.sub.1 to C.sub.5 alkoxy group which is straight-chain or branched and optionally substituted by fluorine, chlorine, bromine, iodine, C.sub.1 to C.sub.5 alkoxy and/or C.sub.1 to C.sub.5 alkylthio, or represents a radical of the general formula ##STR2## wherein R.sup.8 and R.sup.9 independently of each other represent a phenyl radical which is optionally substituted by fluorine, bromine, and/or iodine, or represent a straight-chain or branched C.sub.1 to C.sub.5 alkyl, C.sub.2 to C.sub.5 alkenyl or C.sub.2 to C.sub.5 alkinyl group, or wherein PA1 R.sup.8 and R.sup.9, together with the nitrogen atom to which they are bonded, represent a pyrrolidyl radical which is optionally substituted by methyl and/or ethyl, represent a morpholinyl radical which is optionally substituted by methyl, or represent an azacycloheptyl, piperidyl, 3-methyl-piperidyl, 4-methyl-piperidyl, 2-ethyl-piperidyl, 4-ethyl-piperidyl, 2,3-dimethyl-piperidyl, 2,4-dimethyl-piperidyl, 2,5-dimethyl-piperidyl, or 3,5-dimethyl-piperidyl radical. The trifluoromethyl-phenoxy-phenyl-silicon compounds are useful as herbicides and plant growth regulators. Disclosed are compositions containing the same and methods for their preparation.

The preparation and the use of the active compounds according to the 
invention are evident from the Examples which follow. 
PREATIVE EXAMPLES 
Example 1 
##STR63## 
18.1 g (0.05 mol) of 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitro-benzoic 
acid are dissolved in 100 ml of dimethylsulphoxide. 9.8 g of 
diazabicycloundecane are added at 20.degree. C., while cooling. The 
mixture is stirred for a further half hour. 7.4 g (0.06 mol) of 
chloromethyl-trimethylsilane are then added dropwise at 20.degree. C., and 
the mixture is heated at 100.degree. C. for 20 hours. The reaction mixture 
is thereafter concentrated, and the residue is taken up in toluene. The 
organic phase is washed successively with dilute hydrochloric acid, 
aqueous sodium hydroxide solution and water, and is then dried and 
evaporated down. The residue is dissolved in ligroin, the solution is 
stirred under active charcoal, the latter is filtered off under suction 
over kieselguhr, and the filtrate is then concentrated. 20 g (89% of 
theory) of trimethyl-silyl-methyl 
5-(2-chloro-4-trifluoromethyl-phenoxy)-2-nitro-benzoate are obtained as a 
viscous oil. 
EXAMPLE 2 
##STR64## 
16.8 g (0.11 mol) of diazabicycloundecane are added dropwise to 40 g (0.09 
mol) of 
2-(5-(2,6-dichloro-4-trifluoromethyl-phenoxy)-2-nitro-phenoxy)-propionic 
acid and 100 g of acetone at 20.degree. C., whilst cooling. 13.8 g (0.11 
mol) of chloromethyl-trimethylsilane are then added dropwise at 20.degree. 
C. The reaction mixture is stirred for 20 hours at 50.degree. C. and is 
then concentrated, and 300 ml of water are added. The pH value is adjusted 
to 5 by the addition of glacial acetic acid, the mixture is extracted with 
toluene, and the organic phase is concentrated. 39.5 g (83% of theory) of 
trimethylsilylmethyl 
2-(5-2,6-dichloro-4-trifluoromethyl-phenoxy)-2-nitro-phenoxy)-propionate 
are obtained as an oil of refractive index n.sub.D.sup.20 : 1.5325. 
EXAMPLE 3 
##STR65## 
18.7 g of diazabicycloundecene are added dropwise to 33.3 g (0.1 mol) of 
5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrophenol and 150 ml of 
dimethylsulphoxide at 20.degree. C., whilst cooling. 15.1 g (0.123 mol) of 
chloromethyl-trimethylsilane are added dropwise, and the reaction mixture 
is heated at 100.degree. C. for 6 hours. The reaction mixture is then 
concentrated. The residue which remains is taken up in toluene. The 
organic phase is washed successively with dilute hydrochloric acid, 
aqueous sodium hydroxide solution and water, and is dried and 
concentrated. 22.2 g (53% of theory) of 
5-(2-chlorotrifluoromethyl-phenoxy-2-nitro-phenoxy)-methyl-trimethylsilane 
are obtained as a yellow oil of refractive index n.sub.D.sup.20 : 1.5368. 
The compounds of the formula (I) which are listed in Table 7 below are 
prepared analogously to Example 1, 2 or 3: 
TABLE 7 
__________________________________________________________________________ 
##STR66## 
Example Melting 
No. X.sup.1 
X.sup.2 
X.sup.3 
X.sup.4 
Y R.sup.1 
R.sup.2 
R.sup.3 
R.sup.4 
R.sup.5 
R.sup.6 
R.sup.7 
m n p point [.degree.C.] 
__________________________________________________________________________ 
4 Cl 
Cl 
3-CO.sub.2 
4-NO.sub.2 
H H CH.sub.3 
CH.sub.3 
CH.sub.3 
1 0 0 61 
5 Cl 
Cl 
3-O 4-NO.sub.2 
H H CH.sub.3 
CH.sub.3 
CH.sub.3 
1 0 0 78-79 
__________________________________________________________________________ 
The herbicidal and plant growth regulating activity of the compounds of 
this invention is illustrated by the following biotest Examples. 
In these Examples, the compounds according to the present invention are 
each identified by the number (given in brackets) of the corresponding 
preparative Example. 
The known comparison compound is identified as follows: 
##STR67## 
Sodium 5-(2-chloro-4-trifluoromethyl-phenoxy)-2-nitrobenzoate (disclosed 
in German Offenlegungsschrift No. 2,311,638 or U.S. Pat. No. 4,063,929). 
Example A 
Post Emergence Test 
Solvent: 5 parts by weight of acetone 
Emulsifier: 1 part by weight of alkylaryl polyglycol ether 
To produce a suitable preparation of active compound, 1 part by weight of 
active compound was mixed with the stated amount of solvent, the stated 
amount of emulsifier was added and the concentrate was diluted with water 
to the desired concentration. 
Test plants which had a height of 5 to 15 m were sprayed with the 
preparation of the active compound in such a way as to apply the 
particular amount of active compound desired per unit area. The 
concentration of the spray liquor was so chosen that the particular amount 
of active compound desired was applied in 2,000 liters of water/ha. After 
three weeks, the degree of damage to the plants was rated in % damage in 
comparison to the development of the untreated control. The figures 
denoted: 
0%=no action (like untreated control) 
100%=total destruction 
In this test, the active compounds (1), (2), (3) and (4) showed a better 
selective herbicidal activity than the comparative substance (A). 
Example B 
Defoliation and desiccation of the leaves of cotton 
Solvent: 30 parts by weight of dimethylformamide 
Emulsifier: 1 part by weight of polyoxyethylene sorbitane monolaurate 
To produce a suitable preparation of active compound, 1 part by weight of 
active compound was mixed with the stated amounts of solvent and 
emulsifier and the mixture was made up to the desired concentration with 
water. 
Cotton plants were grown in a greenhouse until the 5th secondary leaf had 
unfolded completely. In this stage, the plants were sprayed with the 
preparations of active compound until dripping wet. After 1 week, the 
shedding of leaves and the desiccation of the leaves were rated, in 
comparison with the control plants. 
The figures of merit had the following meanings: 
0 denoted no desiccation of the leaves, no shedding of leaves 
+ denoted slight desiccation of the leaves, slight shedding of leaves 
++ denoted severe desiccation of the leaves, severe shedding of leaves 
+++ denoted very severe desiccation of the leaves, very severe shedding of 
leaves. 
In this test, the active compounds (1), (2), (3) and (4) showed a powerful 
to very powerful activity. 
It will be understood that the specification and examples are illustrative, 
but not limitative of the present invention and that other embodiments 
within the spirit and scope of the invention will suggest themselves to 
those skilled in the art.