Thiazolylalkyl esters of .alpha.-imidazolinonenicotinic acids and herbicidal methods of use

Novel thiazolylalkyl and thienylalkyl esters of .alpha.-imidazolinone-nicotinic and .alpha.-imidazolinonebenzoic acids of formula I below have good selective herbicidal properties pre- and postemergence and also influence or inhibit plant growth. The Novel esters have the formula I ##STR1## wherein A is a stright chain or branched C.sub.1 -C.sub.6 alkylene bridge, PA1 Q and Q.sub.1 are each independently of the other nitrogen or the methine group, PA1 R.sub.1 and R.sub.2 are each independently of the other hydrogen or C.sub.1 -C.sub.4 alkyl, and PA1 X and Y are each independently of the other hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.3 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 haloalkyl or halogen, or together they are the butadiene radical. ,

The present invention relates to novel herbicidal and plant growth 
regulating thiazolylalkyl and thienylalkyl esters of 
.alpha.-imidazolinonenicotinic and .alpha.-imidazolinonebenzoic acids, as 
well as to the preparation of these novel compounds. The invention also 
relates to compositions containing the novel imidazolinone compounds, and 
to methods of using them for selectively controlling weeds or for 
regulating plant growth. 
The novel thiazolylalkyl and thienylalkyl esters of 
.alpha.-imidazolinonenicotinic and .alpha.-imidazolinonebenzoic acids have 
the formula I 
##STR2## 
wherein A is a straight chain or branched C.sub.1 -C.sub.6 alkylene 
bridge, 
Q and Q.sub.1 are each independently of the other nitrogen or the methine 
group, 
R.sub.1 and R.sub.2 are each independently of the other hydrogen or C.sub.1 
-C.sub.4 alkyl, and 
X and Y are each independently of the other hydrogen, C.sub.1 -C.sub.4 
alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.3 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 
haloalkyl or halogen, or together they are the butadiene radical. 
In the above definitions, the alkyl and alkylene groups may be straight 
chain or branched, e.g. methyl, methylene, ethyl, ethylene, propyl, 
propylene, isopropyl, 1- or 2-methylethylene, butyl, butylene, sec-butyl, 
1-methylpropylene, isobutyl, 2-methylpropylene, tert-butyl, 
2,2-dimethylethylene and 1,2-dimethylethylene. 
Halogen is fluorine, chlorine, bromine or iodine. 
The preparation of such compounds can be represented by the following 
scheme: 
##STR3## 
The process of the present invention for the preparation of the 
imidazolinone compounds of formula I comprises reacting a compound of 
formula IIa or IIb. 
##STR4## 
in which formulae Q, X and Y are as defined for formula I, with a 
thialzolyl alcohol or thienyl alcohol of formula III 
##STR5## 
wherein A, Q.sub.1, R.sub.1 and R.sub.2 are as defined for formula I, in 
an inert organic solvent or diluent and in the presence of a base. 
Suitable solvents for these reactions are substantially anhydrous 
hydrocarbons, ethers or ketones, e.g. benzene, toluene, xylene, hexane, 
cyclohexane, diisopropyl ether, tetrahydrofuran and dioxane. 
Examples of suitable bases are sodium hydride, 
1,8-diazabicyclo[5.4.0]-undec-7-ene, tertiary amines and alkali metal 
hydroxides. 
These reactions are carried out in the temperature range from 0.degree. to 
200.degree. C., generally at the boiling point of the reaction mixture. 
The starting materials of formula IIa are known or they can be prepared by 
known methods, e.g. in accordance with published European patent 
application 41 623 by condensing, under basic conditions, an 
N-(.alpha.-isopropyl-.alpha.-methylacetamido)-2,3-pyridinecarboximide or 
N-(.alpha.-isopropyl-.alpha.-methylacetamido)phthalimide according to the 
following scheme: 
##STR6## 
The N-(.alpha.-isopropyl-.alpha.-methylacetamido)phthalimide can be 
obtained by condensation of phthalic anhydride with 
2-amino-(.alpha.-isopropyl-.alpha.-methylacetonitrile). The nitrile must 
subsequently be converted into the acid amide by heating in aqueous acid. 
A pyridine-2,3-dicarboxylic acid .alpha.-isopropyl-.alpha.-methylacetamide 
of formula IV can be prepared in simple manner according to the following 
scheme by condensing an unsaturated hydrazone with a 2-chloro- or 
2-bromo-N-(.alpha.-isopropyl-.alpha.-methylacetonitrile)succinimide and 
subsequently effecting acid hydrolysis: 
##STR7## 
in which formulae each of R' and R" is hydrogen or C.sub.1 -C.sub.4 alkyl, 
Hal is chlorine or bromine, and X and Y are as defined for formula I. 
The starting materials of formula IIb are obtained by converting the above 
N-(.alpha.-isopropyl-.alpha.-methylacetamido)-2,3-pyridinecarboximide or 
N-(.alpha.-isopropyl-.alpha.-methylacetamido)phthalimide, in the presence 
of a base such as sodium hydroxide solution, into the 
2-(4-isopropyl-4-methyl-5-oxoimidazolidine)nicotinic acid derivative 
##STR8## 
which is converted into the starting material of formula IIb 
(2-isopropyl-2-methyl-3H-imidazo[1',2':1,2]pyrrolo[3,4-b]pyridine-3,5-dion 
e) by treatment with a condensing agent in an inert organic solvent, with 
the loss of a water molecule. Such nicotinic acid esters and the 
preparation thereof are described in published European patent application 
41 623. 
Examples of suitable condensing agents for this cyclisation are a molar 
amount of a strong acid, e.g. concentrated sulfuric acid, or of an 
anhydride, or a water absorbing reagent such as cyclohexanecarbodiimide, 
thionyl chloride or phosgene in the presence of a small amount of 
dimethylformamide. Condensation can also be effected by boiling the 
reaction mixture in a water separator. 
If the reactions can not be carried out at room temperature, then they are 
carried out in the temperature range from 0.degree. C. to 200.degree. C., 
i.e. the reaction mixture is heated - if necessary - to its boiling point 
and cooled - if necessary - with ice/water or ice/brine. 
Suitable bases for these condensation or hydrolysis reactions are in 
particular inorganic bases such as sodium hydroxide, sodium carbonate, 
sodium hydride, calcium hydroxide, calcium carbonate, potassium hydroxide, 
potassium carbonate, ammonia and tertiary organic bases such as 
triethylamine. 
Suitable solvents are e.g. polar, aprotic solvents which can be used by 
themselves or in mixtures consisting of at least two solvents. 
Among the novel esters of formula I, very active nicotinic acid esters are 
those in which Q and Q.sub.1 are nitrogen and each of R.sub.1, R.sub.2, X 
and Y is hydrogen or C.sub.1 -C.sub.4 alkyl and which have the formula Ia 
##STR9## 
especially the compounds: 4-methylthiazol-5-ylethyl 
2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotinate, 
4-methylthiazol-5-ylethyl 
5-methyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotina 
te, 
4-methylthiazol-5-ylethyl 
5-n-propyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicoti 
nate, 
4-methylthiazol-5-ylethyl 
5-isopropyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicot 
inate. 
Those nicotinic acid thienylalkyl esters in which Q is nitrogen, Q.sub.1 is 
the methine group and each of R.sub.1, R.sub.2, X and Y is hydrogen or 
C.sub.1 -C.sub.4 alkyl and which have the formula Ib 
##STR10## 
are also effective, especially thiophen-2-ylethyl 
2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotinate, 
4-methylthiophen-2-ylethyl 
5-methyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotina 
te, 
4-methylthiophen-2-ylethyl 
5-ethyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotinat 
e, 
4-methylthiophen-2-ylmethyl 
5-methyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotina 
te, 
4-methylthiophen-2-ylmethyl 
5-ethyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)nicotinat 
e. 
Those benzoic acid thiadiazolylalkyl esters in which Q is methine, Q.sub.1 
is nitrogen and each of R.sub.1, R.sub.2, X and Y is hydrogen or C.sub.1 
-C.sub.4 alkyl, or X and Y together are the butadiene bridge, which esters 
have the formula Ic 
##STR11## 
are also effective. 4-Methylthiadiazol-5-ylethyl 
2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydroimidazolin-2-yl)benzoate is 
particularly effective. 
Good activity is exhibited by those benzoic or naphthoic acid thienylalkyl 
esters in which Q and Q.sub.1 are methine, each of R.sub.1, R.sub.2, X and 
Y is hydrogen or C.sub.1 -C.sub.4 alkyl, or X and Y together are the 
butadiene bridge, which esters have the formula Ie 
##STR12## 
and also by those 3-quinolinic acid thiazolylalkyl and thienylalkyl esters 
in which Q is nitrogen, Q.sub.1 is nitrogen or methine, each of R.sub.1 
and R.sub.2 is hydrogen or C.sub.1 -C.sub.4 alkyl and X and Y together 
form the butadiene bridge, which esters have the formula If 
##STR13## 
The invention relates to all diastereomeric and enantiomeric isomers of the 
compounds of formula I. 
The compounds of formula I are usually successfully applied at 
concentrations of 0.05 to 4 kg/ha, in particular 0.1 to 1 kg/ha. 
When used at low rates of application, the compounds of formula I have good 
selective growth inhibiting and selective herbicidal properties which make 
them most suitable for use in crops of useful plants, preferably in 
cereals, cotton, soybeans, maize and rice. In some cases damage is also 
caused to weeds which have only been controlled up to now with total 
herbicides. 
The mode of action of these compounds is unusual. Many are translocatable, 
i.e. they are absorbed by the plant and transported to other parts of it 
where they then exert their action. Thus, for example, it is possible to 
damage perennial weeds to the roots by surface treatment. Compared with 
other herbicides and growth regulators, the novel compounds of formula I 
are effective even when used at very low rates of application. 
The compounds of formula I have in addition pronounced growth inhibiting 
properties. The growth of both monocots and dicots is inhibited. 
Thus, for example, the compounds of formula I selectively inhibit the 
growth of leguminosae which are frequently planted as cover crops in 
tropical regions, so that, while soil erosion between cultivated plants is 
prevented, the cover crops cannot compete with the cultivated plants. 
Inhibition of the vegetative growth of many cultivated plants permits more 
plants to be sown in a crop area, so that a higher yield may be obtained 
per unit of area. A further mechanism of yield increase using growth 
regulators resides in the fact that nutrients are able increasingly to 
promote flower formation and fruiting, whereas vegetative growth is 
inhibited. 
At higher rates of application of compounds of formula I, all tested plants 
are so severely damaged in their development that they die. 
The invention also relates to herbicidal and growth regulating compositions 
which contain a novel compound of formula I, and also to methods of 
controlling weeds pre- and postemergence and of inhibiting the growth of 
monocots and dicots, especially grasses, tropical cover crops and tobacco 
plant suckers. 
The compounds of formula I are used in unmodified form or, preferably, 
together with the adjuvants conventionally employed in the art of 
formulation, and are therefore formulated in known manner to emulsifiable 
concentrates, directly sprayable or dilutable solutions, dilute emulsions, 
wettable powders, soluble powders, dusts, granulates, and also 
encapsulations in e.g. polymer substances. As with the nature of the 
compositions, the methods of application, such as spraying, atomising, 
dusting, scattering or pouring, are chosen in accordance with the intended 
objectives and the prevailing circumstances. 
The formulations, i.e. the compositions, preparations or mixtures 
containing the compound (active ingredient) of formula I and, where 
appropriate, a solid or liquid adjuvant, are prepared in known manner, 
e.g. by homogeneously mixing and/or grinding the active ingredients with 
extenders, e.g. solvents, solid carriers and, where appropriate, 
surface-active compounds (surfactants). 
Suitable solvents are: aromatic hydrocarbons, preferably the fractions 
containing 8 to 12 carbon atoms, e.g. xylene mixtures or substituted 
naphthalenes, phthalates such as dibutyl phthalate or dioctyl phthalate, 
aliphatic hydrocarbons such as cyclohexane or paraffins, alcohols and 
glycols and their ethers and esters, such as ethanol, ethylene glycol, 
ethylene glycol monomethyl or monoethyl ether, ketones such as 
cyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone, 
dimethyl sulfoxide or dimethylformamide, as well as vegetable oils or 
epoxidised vegetable oils such as epoxidised coconut oil or soybean oil; 
or water. 
The solid carriers used e.g. for dusts and dispersible powders are normally 
natural mineral fillers such as calcite, talcum, kaolin, montmorillonite 
or attapulgite. In order to improve the physical properties it is also 
possible to add highly dispersed silicic acid or highly dispersed 
absorbent polymers. Suitable granulated adsorptive carriers are porous 
types, for example pumice, broken brick, sepiolite or bentonite; and 
suitable nonsorbent carriers are materials such as calcite or sand. In 
addition, a great number of pregranulated materials of inorganic or 
organic nature can be used, e.g. especially dolomite or pulverised plant 
residues. 
Depending on the nature of the compound of formula I to be formulated, 
suitable surface-active compounds are non-ionic, cationic and/or anionic 
surfactants having good emulsifying, dispersing and wetting properties. 
The term "surfactants" will also be understood as comprising mixtures of 
surfactants. 
Suitable anionic surfactants can be both water-soluble soaps and 
water-soluble synthetic surface-active compounds. 
Suitable soaps are the alkali metal salts, alkaline earth metal salts or 
unsubstituted or substituted ammonium salts of higher fatty acids 
(C.sub.10 -C.sub.22), e.g. the sodium or potassium salts of oleic or 
stearic acid, or of natural fatty acid mixtures which can be obtained e.g. 
from coconut oil or tallow oil. Mention may also be made of fatty acid 
methyltaurin salts. 
More frequently, however, so-called synthetic surfactants are used, 
especially fatty sulfonates, fatty sulfates, sulfonated benzimidazole 
derivatives or alkylarylsulfonates. 
The fatty sulfonates or sulfates are usually in the form of alkali metal 
salts, alkaline earth metal salts or unsubstituted or substituted ammonium 
salts and contain a C.sub.8 -C.sub.22 alkyl radical which also includes 
the alkyl moiety of acyl radicals, e.g. the sodium or calcium salt of 
lignosulfonic acid, of dodecylsulfate or of a mixture of fatty alcohol 
sulfates obtained from natural fatty acids. These compounds also comprise 
the salts of sulfuric acid esters and sulfonic acids of fatty 
alcohol/ethylene oxide adducts. The sulfonated benzimidazole derivatives 
preferably contain 2 sulfonic acid groups and one fatty acid radical 
containing 8 to 22 carbon atoms. Examples of alkylarylsulfonates are the 
sodium, calcium or triethanolamine salts of dodecylbenzenesulfonic acid, 
dibutylnaphthalenesulfonic acid, or of a naphthalenesulfonic 
acid/formaldehyde condensation product. 
Also suitable are corresponding phosphates, e.g. salts of the phosphoric 
acid ester of an adduct of p-nonylphenol with 4 to 14 moles of ethylene 
oxide, or phospholipids. 
Non-ionic surfactants are preferably polyglycol ether derivatives of 
aliphatic or cycloaliphatic alcohols, or saturated or unsaturated fatty 
acids and alkylphenols, said derivatives containing 3 to 10 glycol ether 
groups and 8 to 20 carbon atoms in the (aliphatic) hydrocarbon moiety and 
6 to 18 carbon atoms in the alkyl moiety of the alkylphenols. 
Further suitable non-ionic surfactants are the water-soluble adducts of 
polyethylene oxide with polypropylene glycol, ethylenediaminopolypropylene 
glycol and alkylpolypropylene glycol containing 1 to 10 carbon atoms in 
the alkyl chain, which adducts contain 20 to 250 ethylene glycol ether 
groups and 10 to 100 propylene glycol ether groups. These compounds 
usually contain 1 to 5 ethylene glycol units per propylene glycol unit. 
Representative examples of non-ionic surfactants are 
nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, 
polypropylene/polyethylene oxide adducts, 
tributylphenoxypolyethoxyethanol, polyethylene glycol and 
octylphenoxypolyethoxyethanol. 
Fatty acid esters of polyoxyethylene sorbitan, such as polyoxyethylene 
sorbitan trioleate, are also suitable non-ionic surfactants. 
Cationic surfactants are preferably quaternary ammonium salts which 
contain, as N-substituent, at least one C.sub.8 -C.sub.22 alkyl radical 
and, as further substituents, unsubstituted or halogenated lower alkyl, 
benzyl or hydroxy-lower alkyl radicals. The salts are preferably in the 
form of halides, methylsulfates or ethylsulfates, e.g. 
stearyltrimethylammonium chloride or benzyldi(2-chloroethyl)ethylammonium 
bromide. 
The surfactants customarily employed in the art of formulation are 
described e.g. in the following publications: 
"McCutcheon's Detergents and Emulsifiers Annual", MC Publishing Corp., 
Ridgewood, New Jersey, 1981; H. Stache, "Tensid-Taschenbuch" (Handbook of 
Surfactants), C. Hanser Verlag, Munich & Vienna, 1981. 
The compositions usually contain 0.1 to 95%, preferably 0.1 to 80%, of a 
compound of formula I, 1 to 99.9% of a solid or liquid adjuvant, and 0 to 
25%, preferably 0.1 to 25%, of a surfactant. 
Preferred formulations are composed in particular of the following 
constituents (%=percentage by weight): 
______________________________________ 
Emulsifiable concentrates 
compound of formula I 
1 to 20%, preferably 5 to 10% 
surfactant 5 to 30%, preferably 10 to 20% 
liquid carrier 50 to 94%, preferably 70 to 85% 
Dusts 
compound of formula I 
0.1 to 10%, preferably 0.1 to 1% 
solid carrier 99.9 to 90%, preferably 99.9 to 99% 
Suspension concentrates 
compound of formula I 
5 to 75%, preferably 10 to 50% 
water 94 to 25%, preferably 90 to 30% 
surfactant 1 to 40%, preferably 2 to 30% 
Wettable powders 
compound of formula I 
0.5 to 90%, preferably 1 to 80% 
surfactant 0.5 to 20%, preferably 1 to 15% 
solid carrier 5 to 95%, preferably 15 to 90% 
Granulates 
compound of formula I 
0.5 to 30%, preferably 3 to 15% 
solid carrier 99.5 to 70%, preferably 97 to 85%. 
______________________________________ 
Whereas commercial products will be preferably formulated as concentrates, 
the end user will normally employ dilute formulations. The formulations 
can be diluted to a concentration as low as 0.001% of active ingredient. 
The rates of application are usually from 0.005 to 5 kg a.i./ha. 
The compositions may also contain further ingredients such as stabilisers, 
antifoams, viscosity regulators, binders, tackifiers, as well as 
fertilisers and other compounds for obtaining special effects.