Plant protecting and regulating compositions – Plant growth regulating compositions – Organic active compound containing
Patent
1997-02-03
1998-03-03
Powers, Fiona T.
Plant protecting and regulating compositions
Plant growth regulating compositions
Organic active compound containing
548210, A01N 4380, C07D41706
Patent
active
057234159
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP95/02974 filed Jul. 27, 1995.
The present application relates to 5-hydroxypyrazol-4-ylcarbonyl-substituted saccharin derivatives of the formula I ##STR3## where the substituents have the following meanings: L and M are hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -alkylthio, chlorine, cyano, methylsulfonyl, nitro or trifluoromethyl; C.sub.3 -C.sub.6 -alkenyl, C.sub.3 -C.sub.5 -alkynyl, C.sub.1 -C.sub.4 -acyl or benzyl or phenyl, each of which is unsubstituted or substituted by halogen or C.sub.1 -C.sub.4 -alkyl; ##STR4## where R.sup.1 is C.sub.1 -C.sub.4 -alkyl and
The invention further relates to herbicidal compositions, containing the Compounds I, and methods of controlling undesired plant growth using the saccharin derivatives I.
Saccharin derivatives having herbicidal action cannot be inferred from the prior art. However, unsubstituted saccharin (o-sulfobenzimide, ie. L, M, Q and Z in formula I=H) has been known as a synthetic sweetener for a long time. 4-Hydroxysaccharin is further known as a sweetener (German Offenlegungsschrift 3 607 343). The use of saccharin derivatives in pest control is also known, eg. JP Publication 72/00419, 73/55457 (fungicides) and in pharmacy, eg. EP-A 594 257 and patents further mentioned therein. Heterocyclic compounds having a sulfonamide-containing ring have been disclosed as herbicides, a typical representative which can be mentioned here being bentazone ##STR5##
It is an object of the present invention to make available novel herbicides having a basic structure which was hitherto unknown for this indication.
We have found that this object is achieved by the compounds I defined at the outset.
Compounds of the formula I are obtained by acylating 5-hydroxypyrazoles of the formula II with an acid chloride of the formula IV and rearranging the pyrazole ester formed to give saccharin derivatives of the formula I.1, ##STR6##
In the abovementioned formulae, L, M and Z have the meanings given at the outset.
The first step of the reaction sequence, the acylation, is carried out in a generally known manner, eg. by addition of an acid chloride of the formula IV to the solution or suspension of a 5-hydroxypyrazole II in the presence of an auxiliary base. The reactants and the auxiliary base are in this case expediently employed in approximately equimolar amounts. A small excess of the auxiliary base, eg. from 1.2 to 1.5 mol equivalents, based on II, can be advantageous in certain circumstances.
Suitable auxiliary bases are tertiary alkylamines, pyridine or alkali metal carbonates, while the solvents used can be eg. methylene chloride, diethyl ether, toluene or ethyl acetate. During the addition of the acid chloride, the reaction mixture is preferably cooled to 0.degree.-10.degree. C., then stirred at higher temperature, eg. at 25.degree.-50.degree. C., until the reaction is complete.
Working up is carried out in a customary manner, eg. the reaction mixture is poured into water and extracted with methylene chloride. After drying the organic phase and removing the solvent, the crude 5-hydroxypyrazole ester can be employed for the rearrangement without further purification. Preparation examples for benzoic acid esters of 5-hydroxypyrazoles are found eg. in EP-A 282 944 or U.S. Pat. No. 4,643,757.
The rearrangement of the 5-hydroxypyrazole esters to the compounds of the formula 1.1 is expediently carried out at from 20.degree. C. to 40.degree. C. in a solvent and in the presence of an auxiliary base, and with the aid of a cyano compound as a catalyst. The solvents used can be eg. acetonitrile, methylene chloride, 1,2-dichloroethane, ethyl acetate or toluene. The preferred solvent is acetonitrile. Suitable auxiliary bases are tertiary alkylamines, pyridine or alkali metal carbonates, which are employed in an equimolar amount or an up to four-fold excess. A preferred auxiliary base is triethylamine in a doubled amount. Suitable catalysts are cyanide compounds such as potassium cyanide or acetone cyanohydrin, eg. in an a
REFERENCES:
patent: 4006007 (1977-02-01), Bollinger et al.
patent: 4146726 (1979-03-01), Konotsune et al.
patent: 4410353 (1983-10-01), Theissen
patent: 5306818 (1994-04-01), Subramanyam et al.
Chem. Abst., vol. 98, No. 15, AN 125661W, 1983.
Derwent Abstract of BE 768172 (Dec. 7, 1971).
Derwent Abstract of JP 73-035,457 (Oct. 27, 1973).
Derwent Abstract of JP 57-016,867 (Jan. 28, 1982).
Deyn Wolfgang von
Engel Stefan
Gerber Matthias
Kardorff Uwe
Konig Hartmann
BASF - Aktiengesellschaft
Powers Fiona T.
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