Oxime amides and hydrazone amides having fungicidal activity

Details Oxime amides and hydrazone amides having fungicidal activity Oxime amides and hydrazone amides having fungicidal activity

2001-08-21

2002-03-19

Higel, Floyd D. (Department: 1626)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

C549S076000, C549S496000, C549S495000, C514S438000, C514S461000

Reexamination Certificate

active

06359156

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to compounds useful in the control of Take-All disease in plants, particularly cereals, a method for the control of Take-All disease, fungicidal compositions for carrying out the method, and processes for the preparation of the compounds of the present invention.
BACKGROUND OF THE INVENTION
Take-All disease is a serious problem in the production of cereals, particularly wheat and barley. It is caused by the soil-borne fungus
Gaeumannomyces graminis
var.
tritici
(Ggt). The fungus infects the roots of the plant, and grows throughout the root tissue, causing a black rot. The growth of the fungus in the roots and lower stem prevents the plant from obtaining sufficient water and/or nutrients from the soil, and is manifested as poor plant vigor and, in severe instances of disease, the formation of “whiteheads,” which are barren or contain few, shriveled grains. Yield losses result.
Gaeumannomyces graminis
species also infect other cereal crops, for example, rice and oats, and turf.
Currently the primary means of avoiding crop loss due to infestation of the soil by Ggt has been to rotate the crop grown to one which is resistant to Ggt. In areas where the primary crops are cereals, however, rotation is not a desirable practice, and an effective control agent is greatly desired.
It is an object of this invention to provide an effective method for control of Take-All disease in plants. It is a further object of this invention to provide compounds that control the growth of Ggt in the soil so as to reduce crop loss. It is a still further object of this invention to provide fungicidal compositions that may be used for control of Take-All disease.
Control of Take-All disease has been the subject of a number of commonly assigned patents, including U.S. Pat. Nos. 5,482,974, 5,486,621, 5,693,667 and 5,705,513. Published foreign applications include EP 0538231 A1 and WO 95/24380.
This invention includes a new family of chemical compounds found effective for control of Take-All disease which are different from those disclosed in the previous patents and published applications, as will be seen in the description and Examples below.
International Publication No. WO 96/23763 is assigned to Bayer AG and relates to alkoximino acetic acid amides for use as fungicides. In some respects, the compounds are similar to those of the present invention. They differ in requiring ring compounds in the amide group, and in the preferred oxime geometry. More importantly, of the many fungal species mentioned in the application, there is no reference to the fungus responsible for Take-All disease, Ggt.
SUMMARY OF THE INVENTION
In one aspect, the present invention is a family of chemical compounds having the following structural formula:
where
X and Y are each CH when Z is CH═CH, O, or S; or
X is O or S when Y and Z are CH; or
X is CH
2
or CH
2
CH
2
when Y and Z are each CH
2
;
W is O or S;
Q is O, NH, or NMe;
n=0-2;
R is independently selected from halo or alkyl;
R
1
is selected from the group consisting of C
1
-C
10
straight or branched alkyl, alkenyl, or alkynyl groups, each optionally substituted with one or more halogen, alkoxy, alkylthio; alkoxy, alkenoxy, alkynoxy, dialkylamino, or alkylthio;
R
2
is selected from the group consisting of hydrogen;
C
1
-C
6
straight or branched alkyl, alkenyl, or alkynyl groups, each optionally substituted with one or more halogen;
R
3
, R
4
and R
5
are independently selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and phenyl, each optionally substituted with halogen, alkoxy, or alkylthio;
any two of said R
3
, R
4
and R
5
groups optionally combined to form a cyclo group which is cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.
In another aspect, the invention is a new method of controlling Take-All disease by applying an effective amount of compounds defined above to the plant locus, preferably along with an adjuvant. It has been found that the effectiveness of the new compounds is often affected by their isomeric form. In general, Z geometric isomers are preferred over E geometric isomers.
Compounds of the invention may be classified as oximes or hydrazones of arylgloxamides or heteroarylglyoxamides or cycloalkenylglyoxamides, depending on the definitions of Q, X, Y, and Z in the general formula.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Definitions
As used herein, the term “alkyl,” unless otherwise indicated, means an alkyl radical, with a straight or branched chain, having from 1-10 carbon atoms, with 1-6 carbon atoms being preferred. The terms “alkenyl” and “alkynyl” mean unsaturated radicals having from 2-7 carbon atoms, with 2-4 carbon atoms being preferred. Examples of such alkenyl groups include ethenyl, 1-methylethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, and 2-methyl-2-propenyl. Examples of such alkynyl groups include ethynyl, 1-propynyl, 2-propynyl, and 1,1-dimethyl-2-propynyl. Substituent groups may also be both alkenyl and alkynyl, for example, 6,6-dimethyl-2-hepten-4-ynyl.
As used herein, the term “alkoxy” means an alkyl group having, unless otherwise indicated, from 1-10 carbon atoms connected via an ether linkage. Examples of such alkoxy groups include methoxy, ethoxy, propoxy, 1-methylethoxy, and so forth.
As used herein, the term “halo” means a radical selected from chloro, bromo, fluoro, and iodo.
Compounds
The chemical compounds of the invention are generally called oximes, hydrazones of arylgloxamides, heteroarylglyoxamides, or cycloalkenylglyoxamides. They are defined by the following formula:
where X, Y, Z, W, Q, n, R, R
1
, R
2
, R
3
, R
4
and R
5
are defined above.
The compounds include oxime or hydrazone substituents and amide or thioamide substituents, both attached to a ring compound, which may be a phenyl, thienyl, furyl, 1-cyclopentenyl, or 1-cyclohexenyl ring.
As will be seen in the Examples below, the isomers exhibit different biological activity. It has been found that geometric isomers with C(W)NR
1
R
2
and QC(R
3
)
3
in a cis-relationship have better activity for control of Take-All Disease than do the corresponding trans-geometric isomers.
Preferred compounds are those in which the ring is phenyl and
W is O
Q is O
R
1
is propyl or allyl
R
2
is hydrogen
R
3
, R
4
and R
5
are methyl or ethyl.
Processes for Making Compounds
Two general methods for preparing these compounds differ primarily in the order that their synthesis steps are carried out. In the most versatile route, shown below, esters of phenylglyoxylic acid can be prepared through reaction of phenylglyoxylyl chloride with alcohols in the presence of a suitable amine base. These esters are reacted with a salt of an O-(tert-alkyl)hydroxylamine (X═O) or an N-(tert-alkyl)hydrazine (X═NH or NMe) in the presence of a suitable amine base and solvent at reflux temperature to form the corresponding oxime or hydrazone. Suitable amine bases include triethylamine, diisopropylethylamine, and pyridine. Alternatively, the free base of the O-substituted oxime or N-substituted hydrazine can be used in a suitable solvent to directly form the oxime and hydrazone derivatives without an added amine base. Suitable solvents for the above reactions include alcohols such as methanol or ethanol.
For O-(tert-alkyl)hydroxylamines with tert-alkyl groups larger than tert-butyl, such as where R″ is hydrogen or methyl, oxime formation can be mediated by running the reaction in hexane with an equivalent of TiCl
4
.
An E/Z mixture of oximes or hydrazones forms under all of these conditions with the Z isomer usually predominant for the O-(tert-butyl)oximes and N-(tert-butyl)hydrazones, and the E isomer usually predominant for larger O-(tert-alkyl)oximes and N-(tert-alkyl)hydrazones. For small esters of phenylglyoxylate, such as methyl, both O-(tert-alkyl)oximes and N-(tert-butyl)hydrazones can be readily separated by chromatography. Each of the O-(tert-alkyl)oxime geometric isomers can be reacted with a primary amine as solvent i

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