Note: Descriptions are shown in the official language in which they were submitted.
0050/45615 CA 02210909 1997-07-30
Novel 3-(4-cyanophenyl)uracils
The present invention relates to novel 3-(4-cyanophenyl)uracils
5 of the general formula I
A o Rl
N~ ~ CN
~ ~
R3 Y oR4
where the variables have the following -Anings:
A is hydrogen, methyl or amino;
Y is oxygen or sulfur;
20 Rl is hydrogen or halogen;
R2 is hydrogen, halogen, Cl-C6-alkyl, Cl-C6-haloalkyl,
Cl-C6-alkylthio, Cl-C6-alkylsulfenyl or Cl-C6-alkylsulfonyl;
25 R3 is hydrogen, halogen or Cl-C6-alkyl;
R4 is hydrogen, Cl-C6-haloalkyl, Cl-C6-alkyl, C3 -C8-cyclo-
alkyl, C3-C6-alkenyl, C3-C6-alkynyl, (Cl-C6-alkyl)-
carbonyl, (C3-C6-alkenyl)carbonyl, (C3-C6-alkynyl)carbonyl or
alkylsulfonyl, it being possible, if desired, for each of the
last-mentioned 8 radicals to have attached to it one to three
substituents, in each case selected from the group consisting
of
- halogen, nitro, cyano, hydroxyl, C3-C8-cycloalkyl,
C1-C6-alkoxy, C3-C8-cycloalkoxy, C3-C6-alkenyloxy,
C3-C6-alkynyloxy, Cl-C6-alkoxy-Cl-C6-alkoxy,
Cl-C6-alkylthio, Cl-C6-alkylsulfenyl, Cl-C6-alkylsulfonyl,
Cl-C6-alkylideneaminoxy,
- the phenyl, phenoxy or phenylsulfonyl group which can be
unsubstituted or have attached to it one to three
substituents, in each case selected from the group
consisting of halogen, nitro, cyano, Cl-C6-alkyl,
Cl-C6-alkoxy and Cl-C6-haloalkyl,
CA 02210909 1997-07-30
0050/45615
- a 3- to 7-membered heterocyclyl or heterocyclyloxy group
having one to three hetero atoms selected from the group
consisting of two oxygen atoms, two sulfur atoms and 3
nitrogen atoms, it being possible for the heterocycle to
be saturated, partially or fully unsaturated or aromatic
and, if desired, to have attached to it one to three
substituents, in each case selected from the group
consisting of halogen, nitro, cyano, C1-C6-alkyl,
Cl-C6-alkoxy, C1-C6-haloalkyl and (C1-C6-alkyl)carbonyl,
- a group -Co-XR5, -oCo-XR5 or -N(R5)R6 where
X is a chemical bond, oxygen, sulfur or -N(R6)-;
15 R5 is hydrogen, Cl-C6-alkyl, C3-C8-cycloalkyl, C3-C6-alkenyl,
C3-C6-alkynyl, Cl-C6-alkoxy-Cl-C6-alkyl, (C1-C6-alkoxy)-
carbonyl-Cl-C6-alkyl, phenyl or phenyl-Cl-C6-alkyl, it being
possible for the phenyl group and the phenyl ring of the
phenylalkyl group to be unsub~tituted or to have attached to
it one to three radicals, in each case selected from the
group consisting of halogen, nitro, cyano, Cl-C6-alkyl,
C1-C6-haloalkyl, C1-C6-alkoxy and (Cl-C6-alkyl)carbonyl
X and Rs together form a 3- to 7-membered heterocycle, bonded via
nitrogen and having one to three hetero atoms selected from
the group consisting of two oxygen atomR, two sulfur atoms
and 3 nitrogen atoms, it being possible for the heterocycle
to be saturated, partially or fully unsaturated or aromatic
and, if desired, to have attached to it one to three
~ubstituentQ, in each case selected from the group consisting
of halogen, nitro, cyano, Cl-C6-alkyl, Cl-C6-haloalkyl
Cl-C6-alkoxy and ~Cl-C6-alkyl)carbonyl;
and
R6 represents hydrogen, hydroxyl, Cl-C6-alkyl, C3-C8-cycloalkyl
or Cl-C6-alkoxy,
and the agriculturally useful salt~ of those compounds I
where A is hydrogen.
The invention furthermore relates to
CA 02210909 1997-07-30
0050/45615
- the use of the compounds I as herbicides and/or for the
desiccation and/or defoliation of plants,
- herbicidal compositions and compositions for desiccating
and/or defoliating plants which comprise the compounds I as
active ingredients,
- methods of controlling undesirable vegetation and for
desiccating and/or defoliating plants using the compounds I,
- processes for the preparation of the compounds I and of
herbicidal compositions and compositions for desiccating
and/or defoliating plants using the compounds I, and
15 - novel intermediates of the formulae III and IV from which the
compounds I are obtainable.
Regarding the compounds I where A - hydrogen or methyl,
EP-A 255 047 is of particular importance since it discloses quite
20 generally 3-aryluracils of the formula II
Ra o Rl
Rb ~ N ~ Rd II
R3~ O RC
where Ra is hydrogen, C1_4-alkyl, C1_4-haloalkyl, formyl or
30 C2_6-alkanoyl,
Rb is C1_4-alkyl or C1_4-haloalkyl,
R3~ is hydrogen, halogen or C1-C4-alkyl,
Rc is an ether group or a radical R-CO-O-, R-CS-O- or R-SO2-O- and
Rd is halogen or cyano
35 and the salts of the compounds II where Ra = hydrogen,
as herbicides.
Examples of ~-phenyluracils in which the phenyl ring carries a
cyano group para to the uracil radical (Rd)~ and their herbicidal
40 action, however, are not revealed by this document.
Certain l-amino-3-phenyluracils which, however, do not carry a
cyano group on the phenyl ring have already been disclosed as
herbicides in EP-A-517 181 and JP-A 05/025 143.
CA 02210909 1997-07-30
0050/45615
However, the herbicidal or desiccant/defoliant properties of the
known compounds are not always entirely satisfactory.
It was therefore an object of the present invention to provide
5 novel, in particular herbicidally active compounds, which allow
better, tailored control of undesirable plants than this was
possible to date.
The object also extends to the provision of novel compounds which
10 act as desiccants/defoliants.
We have found that this object is achieved by the
3-(4-cyanophenyl)uracils of the formula I and their herbicidal
action.
There have furthermore been found herbicidal compositions which
comprise the compounds I and have a very good herbicidal action.
There have also been found processes for preparing these
compositions and methods of controlling undesirable vegetation
20 using the compounds I.
It has furthermore been found that the compounds I are also
suitable for defoliating and desiccating parts of plants,
suitable plants being crop plants such as cotton, potatoes,
25 oilseed rape, sunflowers, soybeans or field beans, in particular
cotton. Thus, there have been found compositions for the
desiccation and/or defoliation of plants, processes for the
preparation of these compositions, and methods of desiccating
and/or defoliating plants using the compounds I.
Depending on the substitution pattern, the compounds of the
formula I can have one or more chiral centers, in which case they
are present as enantiomer or diastereomer mixtures. The invention
relates to the pure enantiomers or diastereomers and to their
35 mixtures.
If A is hydrogen, the 3-(4-cyanophenyl)uracils I can be present
in the form of their agriculturally useful salts, the type of
salt not being critical, as a rule. In general, suitable salts
40 are salts of those bases which do not adversely affect the
herbicidal action in comparison with the free compounds I.
Particularly suitable basic salts are those of the alkali metals,
preferably sodium and potassium salts, of the alkaline earth
45 metals, preferably calcium and magnesium salts, those of the
transition metals, preferably zinc and iron salts, and also
ammonium salts where, if desired, the ammonium ion can have
CA 02210909 1997-07-30
' ' 0050/45615
attached to it one to three Cl-C4-alkyl or hydroxy-Cl-C4-alkyl
substituents and/or a phenyl or benzyl substituent, preferably
diisopropylammonium, tetramethylammonium, tetrabutylammonium,
trimethylbenzylammonium and trimethyl(2-hydroxyethyl)ammonium
5 salts, furthermore phosphonium 6alts, sulfonium salts, such as,
preferably, tri(Cl-C4-alkyl)sulfonium salts, and sulfoxonium
salts, such as, preferably, tri(Cl-C4-alkyl)sulfoxonium salts.
The organic moieties mentioned for the substituents Rl to R6 or as
10 radicals on phenyl rings or heterocycles are - like the meaning
halogen - collective terms for individual enumerations of the
individual group members. All carbon chains, ie. all alkyl,
haloalkyl, alkoxy, alkylthio, alkylsulfenyl, alkylsulfonyl,
alkylcarbonyl, alkenyl, alkenyloxy, alkenylcarbonyl, alkynyl,
15 alkynyloxy, alkynylcarbonyl and alkylideneaminoxy moieties can be
straight-chain or branched. Unless otherwise indicated,
halogenated substituents preferably have attached to them one to
five identical or different halogen atoms.
20 Examples of individual meanings are:
- halogen: fluorine, chlorine, bromine or iodine;
- Cl-C4-alkyl and the alkyl moieties of Cl-C6-alkoxy-Cl-C6-alkyl
and ( Cl-C6 - alkoxy)carbonyl-Cl-C6-alkyl:
methyl, ethyl, n-propyl, 1-methylethyl, n-butyl,
l-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl,
1-methylbutyl, 2-methylbutyl, 3-methylbutyl,
2,2-dimethylpropyl, l-ethylpropyl, 1,1-dimethylpropyl,
1,2-dimethylpropyl, n-hexyl, 1-methylpentyl, 2-methylpentyl,
3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl,
1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl,
2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl,
2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl,
1-ethyl-1-methylpropyl or 1-ethyl-2-methylpropyl;
- Cl-C6-haloalkyl: a Cl-C6 - alkyl radical as mentioned above
which is partially or fully substituted by fluorine,
chlorine, bromine and/or iodine, eg. chloromethyl, dichloro-
methyl, trichloromethyl, fluoromethyl, difluoromethyl,
trifluoromethyl, chlorofluoromethyl, dichlorofluoromethyl,
chlorodifluoromethyl, 2-fluoroethyl, 2-chloroethyl, 2-bromo-
ethyl, 2-iodoethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl,
2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl,
2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, penta-
fluoroethyl, 2-fluoropropyl,3-fluoropropyI, 2,2-difluoro-
propyl, 2,3-difluoropropyl, 2-chloropropyl, 3-chloropropyl,
CA 02210909 1997-07-30
0050/45615
2,3-dichloropropyl, 2-bromopropyl, 3-bromopropyl, 3,3,3-tri-
fluoropropyl, 3,3,3-trichloropropyl, 2,2,3,3,3-pentafluoro-
propyl, heptafluoropropyl, l-(fluoromethyl)-2-fluoroethyl,
1-(chloromethyl)-2-chloroethyl, 1-(bromomethyl)-2-bromoethyl,
4-fluorobutyl, 4-chlorobutyl, 4-bromobutyl, nonafluorobutyl,
5-fluoropentyl, 5-chloropentyl, 5-bromopentyl, 5-iodopentyl,
undecafluoropentyl, 6-fluorohexyl, 6-chlorohexyl, 6-bromo-
hexyl, 6-iodohexyl or dodecafluorohexyl;
10 - phenyl-C1-C6-alkyl: eg. benzyl, l-phenylethyl, 2-phenylethyl,
1-phenylprop-1-yl, 2-phenylprop-1-yl, 3-phenylprop-1-yl,
1-phenylbut-1-yl, 2-phenylbut-1-yl, 3-phenylbut-l-yl,
4-phenylbut-1-yl, 1-phenylbut-2-yl, 2-phenylbut-2-yl,
3-phenylbut-2-yl, 3-phenylbut-2-yl, 4-phenylbut-2-yl,
1-(phenylmethyl)eth-1-yl, 1-(phenylmethyl)-1-(methyl)eth-1-yl
and 1-(phenylmethyl)prop-1-yl, preferably benzyl, 2-phenyl-
ethyl and 2-phenylhex-6-yl;
- C3-C6-alkenyl and the alkenyl moieties of C3-C6-alkenyloxy and
(C3-C6-alkenyl)carbonyl: prop-1-en-1-yl, prop-2-en-1-yl,
1-methylethenyl, n-buten-l-yl, n-buten-2-yl, n-buten-3-yl,
1-methylprop-1-en-1-yl, 2-methylprop-l-en-1-yl, l-methyl-
prop-2-en-1-yl or 2-methylprop-2-en-1-yl, n-penten-1-yl,
n-penten-2-yl, n-penten-3-yl, n-penten-4-yl, 1-methylbut-
1-en-l-yl, 2-methylbut-1-en-l-yl, 3-methylbut-1-en-1-yl,
1-methylbut-2-en-1-yl, 2-methylbut-2-en-1-yl, 3-methylbut-
2-en-l-yl, 1-methylbut-3-en-1-yl, 2-methylbut-3-en-1-yl,
3-methylbut-3-en-1-yl, 1,1-dimethylprop-2-en-1-yl,
1,2-dimethylprop-1-en-1-yl, 1,2-dimethylprop-2-en-1-yl,
l-ethylprop-1-en-2-yl, 1-ethylprop-2-en-1-yl, n-hex-1-en-
l-yl, n-hex-2-en-l-yl, n-hex-3-en-1-yl, n-hex-4-en-1-yl,
n-hex-5-en-1-yl, 1-methylpent-1-en-1-yl, 2-methylpent-1-en-
1-yl, 3-methylpent-1-en-1-yl, 4-methylpent-1-en-1-yl, '
1-methylpent-2-en-1-yl, 2-methylpent-2-en-1-yl, 3-methylpent-
2-en-1-yl, 4-methylpent-2-en-1-yl, 1-methylpent-3-en-1-yl,
2-methylpent-3-en-1-yl, 3-methylpent-3-en-l-yl, 4-methylpent-
3-en-1-yl, 1-methylpent-4-en-1-yl, 2-methylpent-4-en-1-yl,
3-methylpent-4-en-1-yl, 4-methylpent-4-en-1-yl, l,l-dimethyl-
but-2-en-1-yl, 1,1-dimethylbut-3-en-1-yl, 1,2-dimethylbut-
l-en-l-yl, 1,2-dimethylbut-2-en-1-yl, 1,2-dimethylbut-3-en-
l-yl, 1,3-dimethylbut-1-en-1-yl, 1,3-dimethylbut-2-en-1-yl,
1,3-dimethylbut-3-en-1-yl, 2,2-dimethylbut-3-en-1-yl,
2,3-dimethylbut-l-en-1-yl, 2,3-dimethylbut-2-en-1-yl,
2,3-dimethylbut-3-en-1-yl, 3,3-dimethylbut-1-en-1-yl,
3,3-dimethylbut-2-en-l-yl, l-ethylbut-l-en-l-yl, l-ethylbut-
2-en-1-yl, 1-ethylbut-3-en-l-yl, 2-ethylbut-1-en-1-yl,
2-ethylbut-2-en-l-yl, 2-ethylbut-3-en-1-yl, 1,1,2-trimethyl-
CA 022l0909 l997-07-30
0050/45615
prop-2-en-1-yl, 1-ethyl-1-methylprop-2-en-1-yl, l-ethyl-
2-methylprop-1-en-1-yl or 1-ethyl-2-methylprop-2-en-1-yl;
- C3-C6-alkynyl and the alkynyl moieties of C3-C6-alkynyloxy and
(C3-C6-alkynyl)carbonyl: prop-1-yn-1-yl, prop-2-yn-1-yl,
but-1-yn-1-yl, but-1-yn-3-yl, but-1-yn-4-yl, but-2-yn-1-yl,
pent-1-yn-1-yl, n-pent-1-yn-3-yl, n-pent-1-yn-4-yl,
n-pent-l-yn-5-yl, n-pent-2-yn-1-yl, n-pent-2-yn-4-yl,
n-pent-2-yn-5-yl, 3-methylbut-1-yn-3-yl, 3-methylbut-
1-yn-4-yl, n-hex-l-yn-l-yl, n-hex-1-yn-3-yl, n-hex-1-yn-4-yl,
n-hex-l-yn-S-yl, n-hex-1-yn-6-yl, n-hex-2-yn-1-yl, n-hex-
2-yn-4-yl, n-hex-2-yn-5-yl, n-hex-2-yn-6-yl, n-hex-3-yn-1-yl,
n-hex-3-yn-2-yl, 3-methylpent-1-yn-1-yl, 3-methylpent-1-yn-
3-yl, 3-methylpent-1-yn-4-yl, 3-methylpent-1-yn-5-yl,
4-methylpent-1-yn-1-yl, 4-methylpent-2-yn-4-yl or 4-methyl-
pent-2-yn-5-yl;
- Cl-C6-alkoxy and the alkoxy moieties of
Cl-C6-alkoxy-Cl-C6-alkyl and (C1-C6-alkoxy)carbonyl-
Cl-C6-alkyl: methoxy, ethoxy, n-propoxy, l-methylethoxy,
n-butoxy, l-methylpropoxy, 2-methylpropoxy or l,1-dimethyl-
ethoxy, n-pentoxy, l-methylbutoxy, 2-methylbutoxy, 3-methyl-
butoxy, l,1-dimethylpropoxy, 1,2-dimethylpropoxy,
2,2-dimethylpropoxy, l-ethylpropoxy, n-hexoxy, l-methyl-
pentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy,
1,1-dimethylbutoxy,1,2-dimethylbutoxy, 1,3-dimethylbutoxy,
2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy,
l-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy,
1,2,2-trimethylpropoxy, l-ethyl-l-methylpropoxy or l-ethyl-
2-methylpropoxy;
- Cl-C6-alkylthio: methylthio, ethylthio, n-propylthio,
l-methylethylthio, n-butylthio, 1-methylpropylthio,
2-methylpropylthio, l,l-dimethylethylthio, n-pentylthio,
l-methylbutylthio, 2-methylbutylthio, 3-methylbutylthio,
2,2-dimethylpropylthio, l-ethylpropylthio, n-hexylthio,
1,1-dimethylpropylthio, 1,2-dimethylpropylthio,
1-methylpentylthio, 2-methylpentylthio, 3-methylpentylthio,
4-methylpentylthio, l,l-dimethylbutylthio,
1,2-dimethylbutylthio, 1,3-dimethylbutylthio,
2,2-dimethylbutylthio, 2,3-dimethylbutylthio,
3,3-dimethylbutylthio, l-ethylbutyl-thio, 2-ethylbutylthio,
1,1,2-trimethylpropylthio, 1,2,2-trimethylpropylthio,
1-ethyl-1-methylpropylthio or 1-ethyl-2-methylpropylthio;
CA 02210909 1997-07-30
0050/45615
- (Cl-C6-alkyl)carbonyl: methylcarbonyl, ethylcarbonyl,
n-propylcarbonyl, l-methylethylcarbonyl, n-butylcarbonyl,
l-methylpropylcarbonyl, 2-methylpropylcarbonyl,
l,l-dimethylethylcarbonyl, n-pentylcarbonyl,
1-methylbutylcarbonyl, 2-methylbutylcarbonyl,
3-methylbutylcarbonyl, l,1-dimethylpropylcarbonyl,
1,2-dimethylpropylcarbonyl, 2,2-dimethylpropylcarbonyl,
l-ethylpropylcarbonyl, hexylcarbonyl, l-methylpentylcarbonyl,
2-methylpentylcarbonyl, 3-methylpentylcarbonyl,
4-methylpentylcarbonyl, l,l-dimethylbutylcarbonyl,
1,2-dimethylbutylcarbonyl, 1,3-dimethylbutylcarbonyl,
2,2-dimethylbutylcarbonyl, 2,3-dimethylbutylcarbonyl,
3,3-dimethylbutylcarbonyl, l-ethylbutylcarbonyl,
2-ethylbutylcarbonyl, 1,1,2-trimethylpropylcarbonyl,
1,2,2-trimethylpropylcarbonyl, l-ethyl-l-methylpropylcarbonyl
or l-ethyl-2-methylpropylcarbonyl;
- C1-C4-alkylsulfenyl; methylsulfenyl, ethylsulfenyl,
n-propylsulfenyl, l-methylethylsulfenyl, n-butylsulfenyl,
l-methylpropylsulfenyl, 2-methylpropylsulfenyl, l,l-dimethyl-
ethylsulfenyl, n-pentylsulfenyl, l-methylbutylsulfenyl,
2-methylbutylsulfenyl, 3-methylbutylsulfenyl, 2,2-dimethyl-
propylsulfenyl, l-ethylpropylsulfenyl, l,l-dimethylpropyl-
sulfenyl, 1,2-dimethylpropylsulfenyl, n-hexylsulfenyl,
l-methylpentylsulfenyl, 2-methylpentylsulfenyl, 3-methyl-
pentylsulfenyl, 4-methylpentylsulfenyl, l,l-dimethylbutyl-
sulfenyl, 1,2-dimethylbutylsulfenyl, 1,3-dimethylbutyl-
sulfenyl, 2,2-dimethylbutylsulfenyl, 2,3-dimethylbutyl-
sulfenyl, 3,3-dimethylbutylsulfenyl, l-ethylbutylsulfenyl,
2-ethylbutylsulfenyl, 1,1,2-trimethylpropylsulfenyl,
1,2,2-trimethylpropylsulfenyl, l-ethyl-l-methylpropylsulfenyl
or l-ethyl-2-methylpropylsulfenyl;
- Cl-C4-alkylsulfonyl: methylsulfonyl, ethylsulfonyl,
n-propylsulfonyl, l-methylethylsulfonyl, n-butylsulfonyl,
l-methylpropylsulfonyl, 2-methylpropylsulfonyl, l,l-dimethyl-
ethylsulfonyl, n-pentylsulfonyl, l-methylbutylsulfonyl,
2-methylbutylsulfonyl, 3-methylbutylsulfonyl, 2,2-dimethyl-
propylsulfonyl, l-ethylpropylsulfonyl, l,l-dimethylpropyl-
sulfonyl, 1,2-dimethylpropylsulfonyl, n-hexylsulfonyl,
l-methylpentylsulfonyl, 2-methylpentylsulfonyl, 3-methyl-
pentylsulfonyl, 4-methylpentylsulfonyl, l,l-dimethylbutyl-
sulfonyl, 1,2-dimethylbutylsulfonyl, 1,3-dimethylbutyl-
sulfonyl, 2,2-dimethylbutylsulfonyl, 2,3-dimethylbutyl-
sulfonyl, 3,3-dimethylbutylsulfonyl, l-ethylbutylsulfonyl,
2-ethylbutylsulfonyl, 1,1,2-trimethylpropylsulfonyl,
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0050/45615
1,2,2-trimethylpropylsulfonyl, l-ethyl-1-methylpropylsulfonyl
or 1-ethyl-2-methylpropylsulfonyl;
- Cl-C6-alkylideneaminoxy: acetylideneaminoxy, l-propylidene-
aminoxy, 2-propylideneaminoxy, 1-butylideneaminoxy,
2-butylideneaminoxy or 2-hexylideneaminoxy;
- C3-C8-cycloalkyl: cyclopropyl, cyclobutyl, cyclopentyl,
cyclohexyl, cycloheptyl and cyclooctyl;
- C3-C8-cycloalkoxy: cyclopropyloxy, cyclobutyloxy,
cyclopentyloxy, cyclohexyloxy, cycloheptyloxy and
cyclooctyloxy.
15 Examples of 3- to 7 ;e ~red heterocycles are oxiranyl,
aziridinyl, oxetanyl, tetrahydrofuranyl, tetrahydrothienyl,
pyrrolidinyl, isoxazolidinyl, isothiazolidinyl, pyrazolidinyl,
oxazolidinyl, thiazolidinyl, imidazolidinyl, dioxolanyl, such as
1,3-dioxolan-2-yl and 1,3-dioxolan-4-yl, l,3-dioxan-2-yl,
20 1,3-dioxan-4-yl, 1,3-dithian-2-yl, 1,2,4-oxadiazolidinyl,
1,3,4-oxadiazolidinyl, 1,2,4-thi A~; ~ zolidinyl,
1,3,4-thiadiazolidinyl, 1,2,4-t~iazolidinyl, 1,3,4-triazolidinyl,
2,3-dihydrofuryl, 2,5-dihydrofuryl, 2,3-dihydrothienyl,
2,5-dihydrothienyl, 2,3-pyrrolinyl, 2,5-pyrrolinyl,
25 2,3-isoxazolinyl, 3,4-isoxazolinyl, 4,5-isoxazolinyl,
2,3-isothiazolinyl, 3,4-isothiazolinyl, 4,5-isothiazolinyl,
2,3-dihydropyrazolyl, 3,4-dihydropyrazolyl, 4,5-dihydropyrazolyl,
2,3-dihydrooxazolyl, 3,4-dihydrooxazolyl, thiazolyl, imidazolyl,
1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,4-thi~iazolyl,
30 1,3,4-thiadiazolyl, 1,2,4-triazolyl and 1,3,4-triazolyl,
piperidinyl, tetrahydropyridazinyl, tetrahydropyrimidinyl,
tetrahydropyrazinyl, 1,3,5-tetrahydrotriazinyl and
1,2,4-tetrahydrotriazinyl,
and the following heteroaromatics:
2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyrrolyl, 3-pyrrolyl,
3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl,
4-isothiazolyl, 5-isothiazolyl, 1-pyrazolyl, 3-pyrazolyl,
4-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl,
40 4-thiazolyl, 5-thiazolyl, l-imidazolyl, 2-imidazolyl,
4-imidazolyl, 1,2,4-oxadiazol-3-yl, 1,2,4-ox~ zol-5-yl,
1,2,4-thiadiazol-3-yl, 1,2,4-thi~iAzol-5-yl, 1,2,4-triazol-1-yl,
1,2,4-triazol-3-yl, 1,2,4-triazol-4-yl, 1,3,4-oxadiazol-2-yl,
1,3,4-thiadiazol-2-yl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl,
45 3-pyridazinyl, 4-pyridazinyl, 2-pyrimidinyl, 4-pyrimidinyl,
5-pyrimidinyl, 2-pyrazinyl, 1,3,5-triazin-2-yl and
CA 02210909 1997-07-30
0050/45615
.
1,2,4-triazin-3-yl, in particular pyridyl, pyrimidyl, furanyl and
thienyl.
All phenyl- and heterocyclic rings are preferably unsubstituted
S or have attached to them a halogen, methyl, trifluoromethyl or
methoxy qubstituent.
With a view to the use of the novel compounds of the formula I as
herbicides and~or as compounds with a defoliant/desiccant action,
10 the variables preferably have the following meanings, in each
case on their own or in combination:
A is amino or methyl;
15 Y is oxygen;
Rl is hydrogen, fluorine or chlorine, in particular hydrogen or
fluorine;
20 R2 is Cl-C6-alkyl, Cl-C6-haloalkyl or Cl-C6-alkylsulfonyl, in
particular Cl-C4-haloalkyl, particularly preferably
trifluoromethyl, chlorodifluoromethyl or pentafluoroethyl;
R3 i9 hydrogen or halogen, in particular hydrogen, chlorine or
bromine;
R4 is hydrogen, C1--C6--haloalkyl,Cl--C6--alkyl,C3--C8--cyclo-
alkyl, C3-C6-alkenyl, C3-C6-alkynyl, (Cl-C6-alkyl)-
carbonyl, (C3-C6-alkenyl)carbonyl or (C3-C6-alkynyl)-
carbonyl, it being possible, if desired, for each of the
last-mentioned 8 radicals to have attached to it one or two
~ubstituents, in each case selected from the group consisting
of halogen, nitro, cyano, hydroxyl, C3-C8-cycloalkyl,
C1--C6--alkoxy,C3--CB--cycloalkoxy, c3-c6-alkenyloxy~
C3-C6-alkynyloxy, Cl-C6-alkoxy-Cl-C6-alkoxy, Cl-C6-alkylthio,
Cl-C6-alkylsulfenyl, Cl-C6-alkylsulfonyl,
C1--C6--alkylideneaminoxy,--Co--XR5,~ Co--XR5or --N(R5)R6, in
particular hydrogen, Cl-C4-alkyl, C3-C6-cycloalkyl,
C3-C4--alkenyl, C3-C4--alkynyl, Cl-C4-haloalkyl,
Cl-C4-alkoxy-C1-C4-alkyl, (C1-C4-alkyl)carbonyl, -CH2-Co-XR5,
-CH(CH3 )-Co-XR5 or C1-C4-cyanoalkyl, such as cyanomethyl,
l-cyanoeth-l-yl, 2-cyanoeth-1-yl, l-cyanoprop-1-yl,
2-cyanoprop-1-yl, 3-cyanoprop-1-yl, 1-cyanoprop-2-yl,
2-cyanoprop-2-yl, 1-cyanobut-1-yl, 2-cyanobut-1-yl,
3-cyanobut-1-yl, 4-cyanobut-1-yl, 1-cyanobut-2-yl,
2-cyanobut-2-yl, 1-cyanobut-3-yl, 2-cyanobut-3-yl,
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11
1-cyano-2-methylprop-3-yl, 2-cyano-2-methylprop-3-yl,
3-cyano-2-methylprop-3-yl and 2-cyano-methylprop-2-yl;
5 X is a chemical bond, oxygen or -N(R6)-;
R5 is hydrogen, Cl-C6-alkyl, C3-C8-cycloalkyl, C3-C6-alkenyl,
C3-C6-alkynyl, C1-C6-alkoxy-C1-C6-alkyl or
(C1-C6-alkoxy)carbonyl-C1-C6-alkyl, in particular hydrogen,
C1-C6-alkyl, C3-C8-cycloalkyl, C1-C6-alkoxy-C1-C6-alkyl or
(C1-C6-alkoxy)carbonyl-C1-C6-alkyl,
R6 is hydrogen, C1-C6-alkyl or C1-C6-alkoxy.
Very particularly preferred are the compounds Ia which are listed
15 in Table 1 below (~ I where A = amino, Y = oxygen, R1 = fluorine,
R2 = trifluoromethyl, R3 = hydrogen):
H2~ ~ O F
N ~ CN Ia
~\ ~
H O oR4
25 Table 1
No. R4
Ia.01 H
Ia.02 CH3
30 Ia.03 C2H5
Ia.04 n-C3H7
Ia.05 CH(CH3)2
Ia.06 n-C4Hg
Ia.07 i-C4Hg
Ia.08 8-C4Hg
Ia.09 C(CH3)3
Ia.10 cyclopropyl
Ia.ll cyclobutyl
Ia.12 cyclopentyl
Ia.13 cyclohexyl
Ia.14 cycloheptyl
Ia.15 cyclooctyl
45 Ia.16 CH2CN
Ia.17 CH2CH2CN
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12
No. R4
Ia.18 CH(CH3)CN
Ia.l9 C(CH3)2CN
5 Ia.20 C(CH3)2CH2CN
Ia.2l CH2Cl
Ia.22 CH2CH2Cl
Ia.23 CH(CH3)CH2Cl
Ia.24 CH2CF3
Ia.25 CHC12
Ia.26 CF2Cl
Ia.27 CF3
Ia.28 C2Fs
15 Ia.29 CF2H
Ia.30 CH2-CH=CH2
Ia.31 CH~CH3)-CH=cH2
Ia.32 CH2-CH=CH-CH3
20 Ia.33 CH2-C-CH
Ia.34 CH(CH3)-C-CH
Ia.35 C(CH3)2-C-CH
Ia.36 CH2-COOH
25 Ia.37 CH2-CO-OCH3
Ia.38 CH2-CO-OC2H5
Ia.39 CH2-CO-O-n-C3H7
Ia.40 CH2-CO-OCH(CH3)2
Ia.41 CH(CH3)-CO-OCH3
30 Ia.42 CH(CH3)-CO-OC2H5
Ia.43 CH(CH3)-CO-O-n-C3H7
Ia.44 CH(CH3)-CO-OC(CH3)2
Ia.45 CH2-COO-(CH2)2-OCH3
35 Ia.46 CH2-COO-~CH2)2-OCH3
Ia.47 CH(CH3)-COO-(CH2)2-OCH3
Ia.48 cH(cH3)-coo-(cH2)2-oc2Hs
Ia.49 CH2-CONH2
40 Ia.50 CH2-CONHCH3
Ia.51 CH2-CONHC2H5
Ia.52 CH2-CON(CH3)2
Ia.53 CH(CH3)-cONH2
Ia.54 CH(CH3)-CONHCH3
Ia.55 CH(CH3)-CONHC2H5
Ia.56 CH(CH3)-CON(CH3)2
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No. R4
Ia.57 CO-CH3
Ia.58 CO-C2H5
5 Ia.59 CO-CH(CH3)2
Ia.60 CO-n-C4Hg
Ia.61 CO-cyclopropyl
Ia.62 CO-cyclopentyl
Ia.63 CO-CF3
Ia.64 CO-OCH3
Ia.65 CO-OC2H5
Ia.66 SO2-CH3
Ia.67 CH2-SCH3
15 Ia.68 (CH2)2-SCH3
Ia.69 (CH2)2-SC2H5
Ia.70 (CH2)2-SO-CH3
Ia.71 (CH2)2-SO2-CH3
20 Ia.72 (CH2)2-SO-CH3
Ia.73 (CH2)2-cyclopropyl
Ia.74 (CH2)2-cyclopentyl
Ia.75 (CH2)2-ONZc~cH3) 2
25 Ia.76 (CH2)3-ON=C(CH3)2
Ia.77 (CH2)2-NO2
Ia.78 (CH2)2-NH2
Ia.79 (CH2)2-NHCH3
Ia.80 (CH2)2-NH(CH3)2
30 Ia.81 CH2-OCH3
Ia.82 CH(CH3)-OCH3
Ia.83 CH(CH3)-OC2H5
Ia.84 CH(CH3)CH2-OCH3
35 Ia.85 (CH2)2OH
Ia.86 CH2-Oc2H5
Ia.87 CH2COO-(4-acetoxytetrahydrofuran-3-yl)
Ia.88 CH2OCOCH3
40 Ia.89 CH2OCOC2H5
Ia.90 CH2C6Hs
Ia.91 (CH2)2-C6H5
Ia.92 CH2-(4-Cl-C6H4)
Ia.93 CH2-(4-CF3-C6H4)
Ia.94 CH2-(3-NO2-C6H4)
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14
Other particularly preferred 3-(4-cyanophenyl)uracils of the
formula I are those which follow:
- the compounds Ib.01 - Ib.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that Rl is
hydrogen:
H2N\ ~ o H
F3C~N~ CN Ib
H o oR4
15 - the compounds Ic.01 - Ic.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that Rl is
chlorine:
/~ CN Ic
H O oR4
- the compounds Id.01 - Id.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that A is
methyl:
H3(~, O F
N~// \~
F3C~N ~_ \~ CN Id
3 5 H ~ oR4
- the compounds Ie.01 - Ie.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that A i8
hydrogen:
/ ~ CN I~3
H O oR4
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- the compounds If.01 - If.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that Rl is
hydrogen and A is methyl:
H3C\N ~ H
F3C ~ N CN If
H ~ oR4
- the compounds Ig.01 - Ig.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that Rl and
A are hydrogen:
F C ~ ~ N ~ CN Ig
H o oR4
- the compounds Ih.01 - Ih.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that R1 i8
chlorine and A is methyl:
~ \ ~ Ih
B o oR4
- the compounds Ii.01 - Ii.94, which only differ from the
corresponding compounds Ia.01 - Ia.94 by the fact that Rl is
chlorine and A is hydrogen:
/o C\
~C ~ N ~ CN Ii
H o oR4
CA 02210909 1997-07-30
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16
- the compounds Ik.Ol - Ik.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that R3 is
chlorine:
5H2N\ ~ o F
F3C~N~ CN Ik
10Cl o oR4
- the compounds Il.O1 - Il.94, which only differ from the
corresponding compounds Ia.O1 - Ia.94 by the fact that R3 is
chlorine and A is methyl:
H3C \ o F
N~
F3C~N~ CN I 1
Cl O oR4
- the compounds Im.O1 - Im.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that R3 is
chlorine and A is hydrogen:
H~ ~ O F
N ~ CN Im
c 1 o oR4
- the compounds In.O1 - In.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that R1 and
R3 are chlorine:
H2N~ ~ O Cl
40F3C ~ N ~ \~ CN In
c 1 o oR4
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- the compounds Io.Ol - Io.94, which only differ from the
corresponding compounds Ia.O1 - Ia.94 by the fact that A is
methyl, Rl is hydrogen and R3 is chlorine:
H3C\ o H
F3C ~ N - ~ CN Io
Cl ~ oR4
- the compounds Ip.Ol - Ip.94, which only differ from the
corresponding compounds Ia.Ol - Ia.94 by the fact that A is
methyl and Rl and R3 are chlorine;
H3C ~ O Cl
F3C ~ N ~ CN Ip
c 1 o oR4
The 3-(4-cyanophenyl)uracils of the formula I can be obt~i neA by
various routes, for example by one of the following processes:
Process A):
Cyclization of an enA ine ester of the formula III or of an
enA 1ne carboxylate of the formula IV in the presence of a base:
O ~ .
\ ~ - NH ~ CN
R2 _ ~ ~ OLl \ \
R3 o III ~ base I (Y=O)
\N ~ - OLl Rl /
R2_ ~ NH ~ CN
R3 IV oR4
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18
Ll is low-molecular-weight alkyl, preferably Cl-C4-alkyl, or
phenyl.
As a rule, the cyclization is carried out in an inert organic
5 solvent or diluent which is aprotic, for example in an aliphatic
or cyclic ether, such as 1,2-dimethoxyethane, tetrahydrofuran and
dioxane, in an aromatic, such as benzene and toluene, or in a
polar solvent, such as dimethylformamide and dimethyl sulfoxide.
Mixtures of polar solvents and a hydrocarbon, such as n-hexane,
10 are also suitable. Depending on the starting material, water may
also be suitable as the diluent.
Suitable bases are, preferably, alkali metal alcoholates, in
particular the sodium alcoholates, alkali metal hydroxides, in
15 particular sodium hydroxide and potassium hydroxide, alkali metal
carbonates, in particular sodium carbonate and potassium
carbonate, and metal hydrides, in particular sodium hydride. If
sodium hydride is used as the base, it has proved advantageous to
carry out the process in an aliphatic or cyclic ether, in
20 dimethylformamide or in dimethyl sulfoxide.
0.5 times to twice the molar amount of base based on the amount
of III or IV is generally sufficient to carry out the reaction
successfully.
In general, the reaction temperature is from ~-78) C to the
boiling point of the reaction mixture in question, in particular
from (-60) to 60~C.
30 If A in formula III or IV is hydrogen, the process product is
obtained as a metal salt, the metal corresponding to the cation
of the base used. The salt can be isolated and purified in a
manner known per se or, if desired, converted using an acid to
obtain the free compound I where A = hydrogen.
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19
Process B):
Methylation of a compound I where A is hydrogen in the presence
of a base:
CN ~C~33~3~ ~ ~2 ~ CN
R3 Y oR4 R3 Y OR4
I (A=H) I (A=CH3)
Examples of suitable methylating agents are methyl halides,
preferably methyl chloride, methyl iodide or methyl bromide, and
also dimethyl sulfate, methyl methanesulfonate (methyl mesylate),
methyl benzenesulfonate, methyl p-toluenesulfonate (methyl
20 tosylate), methyl p-bromobenzenesulfonate (methyl brosylate),
methyl trifluoromethanesulfonate (methyl triflate) and
diazomethane.
As a rule, the process is carried out in an inert organic solvent
25 or in an aprotic solvent, eg. in an aliphatic or cyclic ether,
preferably in 1,2-dimethoxyethane, tetrahydrofuran or dioxane, in
an aliphatic ketone, preferably in acetone, in an amide,
preferably in dimethylformamide, in a sulfoxide, preferably in
dimethyl sulfoxide, in a urea, such as tetramethylurea and
30 1,3-dimethyltetrahydro-2(lH)-pyrimidinone, in a carboxylic ester,
such as ethyl acetate, or in a halogenated aliphatic or aromatic
hydrocarbon, such as dichloromethane and chlorobenzene.
Suitable bases are inorganic bases, eg. carbonates, such as
35 sodium carbonate and potassium carbonate, hydrogen carbonates,
such as sodium hydrogen carbonate or potassium hydrogen
carbonate, or alkali metal hydrides, such as sodium hydride and
potassium hydride, and also organic bases, eg. amines, such as
triethylamine, pyridine and N,N-diethylaniline, or alkali metal
40 alcoholates, such as sodium methanolate, sodium ethanolate and
potassium tert-butanolate.
The amount of base and methylating agent is preferably 0.5 times
to twice the molar amount based on the amount of starting
45 compound.
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0050/45615
In general, the reaction temperature is from 0 C to the boiling
point of the reaction mixture, in particular from 0 to 60~C.
A preferred process variant consists in methylating the salt of
5 I, which has been obtained by cyclizing III (A = H) or IV (A = H)
in accordance with process A) without isolating it from the
reaction mixture, which can still contain excess base, eg. sodium
hydride, sodium alcoholate or ~odium carbonate.
10 If the salts of those compounds I where A is hydrogen cannot be
prepared directly by the cyclization under alkaline conditions,
which has been described as method a), they can also be obtained
from the process products obtained by method a) in a manner known
per se. For this purpose, for example, the aqueous solution of an
15 inorganic or organic base is treated with the substituted
3-(4-cyanophenyl)uracil I where A is hydrogen. Salt formation
usually takes place at sufficiently high rates at as little as
20-25~C.
20 It i8 particularly advantageous to prepare the sodium salt by
dissolving the 3-(4-cyanophenyl)uracil I (A = hydrogen) in
aqueou~ sodium hydroxide solution at 20-25 C, using approximately
equivalent amounts of 3-~4-cyanophenyl)uracil and sodium
hydroxide. The salt of the 3-(4-cyanophenyl)uracil can then be
25 isolated for example by precipitation with a suitable inert
solvent or by evaporating the solvent.
Salts of the 3-(4-cyanophenyl)Yracils whose metal ion is not an
alkali metal ion can generally be prepared by double
30 decomposition of the corresponding alkali metal salt in aqueous
solution. 3-(4-cyanophenyl)uracil metal salts which are insoluble
in water can be prepared in this manner, for example.
CA 02210909 1997-07-30
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21
Process C):
Reaction of a 3-(4-cyanophenyl)uracil of the formula I where A iB
hydrogen with an electrophilic aminating reagent in the presence
of a base;
s
base / ~ CN
R3 Y oR4 R3Y oR4
I (A=H) I (A=NH2)
An aminating reagent which has proved useful to date is
2,4-dinitrophenoxyamine, but hydroxylamine-O-sulfonic acid
(HOSA), which has been disclosed in the literature as aminating
20 reagent, can, for example, also be used (cf., for example,
E. Hofer et al., Synthesis 1983, 466; W. Friedrichsen et al.,
Heterocycles 20 (1983) 1271; H. Hart et al., Tetrahedron Lett.
(1984) 2073; ~. Vercek et al., Monatsh. Chem. 114 (1983) 789; G.
Sosnousky et al., Z. Naturforsch. 38 (1983) 884; R.S. Atki~on et
25 al., J. Chem. Soc. Perkin Trans. 1987, 2787).
Amination can be carried out in a manner known per se (see, for
example, T. Sheradsky, Tetrahedron Lett. 1948, 1909;
M.P. Wentland et al., J. Med. Chem. 27 (1984) 1103, and, in
30 particular, EP-A 240 194, EP-A 476 697 and EP-A 517 181, which
teach the amination of uracils).
The reaction is usually carried out in a polar solvent, eg. in
dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide or in
35 ethyl acetate, which has proved particularly useful to date.
Examples of suitable bases are alkali metal carbonates, such as
potassium carbonate, alkali metal alcoholate~, ~uch as sodium
methylate and potassium tert-butanolate, or alkali metal
40 hydrides, such as sodium hydride.
The amount of base and aminating agent is preferably in each case
0.5 times to twice the molar amount based on the amount of
starting compound.
CA 02210909 1997-07-30
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~ .
22
Depending on the meaning of R4, it may be necessary to protect
this substituent in a manner known per se prior to amination.
This is particularly to be recor ?n~ed if R4 is hydrogen.
5 Process D):
Sulfuration of a 3-~4-cyanophenyl)uracil of the formula I where
Y = oxygen:
A o Rl A o R1
N / ~ CN Sulfuration ~ R2 ~ N ~ CN
R3 ~ oR4 R3 S oR4
I (Y=O) I (Y=S)
The sulfuration is qenerally csrried out in an inert solvent or
diluent, for example in an aromatic hydrocarbon, such as toluene
and the xylenes, in an ether, such as diethyl ether,
1,2-dimethoxyethane and tetrahydrofuran, or in an organic amine,
20 such as pyridine.
Particularly suitable sulfurating reagents are phosphorus(V)
sulfide and 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-
2,4-dithione ("Lawesson's reagent").
1 to 5 times the molar amount based on the starting compound to
be sulfurized is generally sufficient for an essentially complete
reaction.
30 The reaction temperature usually is from 20 to 200 C, preferably
40 C to the boiling point of the reaction mixture.
Process E):
Ether cleavage of a 3-(4-cyanophenyl)uracil of the formula I
35 where R4 is an unsubstituted or substituted alkyl, cycloalkyl,
alkenyl, alkynyl or benzyl:
A o R1 A o Rl
R2 ~ N ~ \~ CN ~ RZ ~ N ~ CN
R3 Y OR4 R3 y OH
~R4 = unsubstituted or I (R4=H)
substituted alkyl, cycloalkyl,
alkenyl, alkynyl)
CA 02210909 1997-07-30
0050/45615
The ether cleava~e is usually effected by means of an acid, eg.
by means of hydrogen bromide, hydrogen iodide or pyridinium
hydrochloride, by means of a Lewis acid, such as aluminum
trichloride, aluminum tribromide, aluminum triiodide, boron
5 trichloride, boron tribromide, boron trifluoride and iron
trichloride, or by mean~ of trimethylsilyl iodide. Other useful
substances for cleaving the ether bond are, however, also lithium
salts, such a~ lithium chloride, or mixtures of an inorganic
iodide and trimethylsilyl chloride. In individual cases, for
10 example when R4 is benzyl, the bond can also be cleaved under
hydrogenation conditions using hydrogen in the presence of a
hydrogenation cataly~t, such as platinum and palladium on active
charcoal.
15 Allyl ether~ (R4 = allyl) can furthermore be converted into the
corresponding phenols in a manner known per se for this purpose,
for example by isomerization in the presence of a transition
metal catalyst to give the enol ether and cleavage of the latter,
preferably under mildly acidic conditions (cf., for example,
20 T. Greene and P.G.M. Wutz in nProtective Groups in Organic
Synthesis", John Wiley & Sons, 2nd Edition, New York 1991, p. 42
et seq.).
The process is generally carried out in an inert solvent or
25 diluent, eg. in an aliphatic, cyclic or aromatic hydrocarbon,
such as n-pentane, petroleum ether, cycloheYAne, benzene, toluene
or xylene, an aliphatic or cyclic ether, such as diethyl ether,
tert-butyl methyl ether, dimethoxyethane and tetrahydrofuran, an
aliphatic or aromatic halogenated hydrocarbon, such as
30 dichloromethane, chloroform, chlorobenzene, 1,2-dichloroethane
and the dichlorobenzenes, an alcohol, such as methanol, ethanol
and tert-butanol, an amide, such as dimethylformamide and
N-methylpyrrolidone, an amine, such as ammonia, or in a mixture
of these.
It may also be advantageous to carry out the reaction in the
absence of a solvent.
With regard to particularly preferred embodiments, mention may be
40 made of the information given in Houben-Weyl, "Methoden der
Organischen Chemie" [Methods in Organic Chemistry], Georg Thieme
Verlag, 4th Edition, Stuttgart 1979, Vol. 6/la/1, p. 309 et seq.,
and in R. C. Larock, "Comprehensive Organic Transformations",
VCH-Publishers, Weinheim 1989, p. 501 et seq., and the literature
45 cited in these publications.
CA 02210909 1997-07-30
'' 0050/45615
24
Process F):
Alkylation of a 3-(4-cyanophenyl)uracil of the formula I where R4
is hydrogen in the presence of a base:
~se ~ CN
R3 y OH R3 Y oR4
I (R4=H) I(R4=~ s~ lt~dors~hs~it~ltçdalkyl,
cycloalkyl, alkenyl or alkynyl)
The alkylation can be carried out, for example, using the halide,
preferably the chloride or bromide, the sulfate, sulfonate,
preferably the methanesulfonate (mesylate), benzenesulfonate,
p-toluenesulfonate (tosylate), p-bromobenzenesulfonate
20 (brosylate), the trifluoromethanesulfonate (triflate) or the
diazo compound of an unsubstituted or substituted alkane,
cycloAlk~ne, haloalkane, alkene or alkyne.
The reaction is usually carried out in an inert organic solvent,
25 suitable solvents being, in particular, aprotic solvents, eg.
aliphatic and cyclic ethers, such as 1,2-dimethoxyethane,
tetrahydrofuran and dioxane, aliphatic ketones, such as acetone,
amides, such as dimethylformamide, sulfoxides, such as dimethyl
sulfoxide, ureas, such as tetramethylurea and
30 1,3-dimethyltetrahydro-2(lH)-pyrimidinone, carboxylic esters,
such as ethyl acetate, or halogenated aliphatic or aromatic
hydrocarbons, such as dichloromethane and chlorobenzene.
Suitable bases are inorganic bases, eg. alkali metal carbonates,
35 such as sodium carbonate and potassium carbonate, alkali metal
hydrogencarbonates, such as sodium hydrogen carbonate and
potassium hydrogen carbonate, or alkali metal hydrides, such as
sodium hydride and potassium hydride, but also organic bases, eg.
amines, such as triethylamine, pyridine and N,N-diethylaniline,
40 or alkali metal alcoholates, such as sodium methanolate, sodium
ethanolate and potassium tert-butanolate.
The amount of base and alkylating agent is preferably 0.5 times
to twice the molar amount based on the amount of I where
45 R4 = hydrogen.
CA 02210909 1997-07-30
0050/45615
In general, a reaction temperature of from 0 C to the boiling
point of the reaction mixture, in particular from 0 to 60 C, is
recommended.
5 Any problems with regioselectivity in the case of starting
compounds where A = hydrogen can be avoided in a manner known per
se (use of 2 equivalents of base, introduction of a protective
group etc.).
10 Process G):
Acylation of a 3-(4-cyanophenyl)uracil of the formula I where R4
is hydrogen with a suitable alkylating agent.
Z = ~ ~ CN
R3 y OH R3 Y oR4
I (R4=H) I(R4=s~hs~h-~Pdor~
alkyl--, alkenyl--or alkynylcarbonyl)
25 Suitable acylating agents are for example the acid halides, in
particular the acid chlorides, the anhydrides, isocyanates or
sulfonylchlorides of alkane-, cycloalkane-, alkene-, alkyne-,
phenyl- or phenylalkanecarboxylic acids. However, the free acids
or their anhydrides are also suitable, under the condition that
30 the process is carried out in the presence of a co~ensing agent,
such as carbonyl diimidazole and dicyclohexylcarbodiimide.
The process is generally carried out in an inert organic solvent
or diluent which is preferably aprotic, eg. in an aliphatic or
35 cyclic ether, such as 1,2-dimethoxyethane, tetrahydrofuran and
dioxane, an aliphatic ketone, such as acetone, an amide, such as
dimethylformamide, a urea, such as tetramethylurea and
1,3-dimethyltetrahydro-2(lH)-pyrimidinone, a carboxylic ester,
such as ethyl acetate, or an aliphatic or aromatic halogenated
40 hydrocarbon, such as dichloromethane and chlorobenzene.
As regards suitable bases, the weight ratios and the reaction
temperature, the information given for process F) applies.
45 Process H):
Substitution of halide by cyanide:
CA 02210909 1997-07-30
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26
Process H):
Substitution of halide by cyanide:
Cll
R3 Y oR4 R3 Y oR4
V
Hal is halogen, preferably fluorine, bromine or iodine.
Suitable cyanides are, in particular, metal cyanides, eg. the
alkali metal cyanides, such as lithium cyanide, sodium cyanide
and potassium cyanide, the alkaline earth metal cyanides, such as
magnesum cyanide, or else transition metal cyanides, such as
20 copper cyanide.
The process is usually carried out in an ether, such as
tetrahydrofuran, dioxane and 1,2-dimethoxyethane, or in an
aprotic polar solvent, eg. an alkyl nitrile, 4uch as
25 acetonitrile, propionitrile and butyronitrile, an alkylurea, such
as N,N,N',N'-tetramethylurea, an open-chain or cyclic
dialkylamide, such as dimethylformamide, N-methyl-2-pyrrolidone,
1,2-dimethylimidazolidin-2-one and
1,2-dimethyl-3,4,5,6-tetrahydro-2(lH)-pyrimidinone, a dialkyl
30 sulfoxide, such as dimethyl sulfoxide, or in hexamethylphosphoric
triamide.
Findings to date have revealed that the presence of a catalyst
may have an advantageous effect on the course of the reaction.
35 Examples of suitable catalysts are transition metals and their
complexes or salts, eg. copper compounds, such as copper(I)
chloride, copper(I) iodide, copper(I) cyanide, or nickel
compounds, such as nickel bis-triphenylphosphine dibromide.
40 In the case of starting compounds V where A = hydrogen, it is
recommended to carry out the process in the presence of a base,
suitable bases being, in particular, weakly nucleophilic bases,
ie. inorganic bases, eg. alkali metal carbonates, such as sodium
carbonate and potassium carbonate, alkali metal hydrogen
45 carbonates, such as sodium hydrogen carbonate and potassium
hydrogen carbonate, or alkali metal hydrides, such as sodium
0OS0/45615 CA 02210909 1997-07-30
27
hydride and potassium hydride, and also organic bases, eg.
amines, such as triethylamine, pyridine and N,N-diethylaniline.
The weight ratios are usually not critical. In general,
5 approximately one to 10 times the amount of cyanide and base,
based on the amount of V, will suffice.
The reaction temperature is usually 50 to 250 C; however, to
increase the selectivity of the reaction, it may also be
10 advantageous to carry out the process at lower temperatures, in
particular at approximately 20~C.
~ith regard to various embodiments of this reaction, reference
may be made to Houben-Weyl, "Methoden der Organischen Chemie"
15 lMethods in Organic Chemistry], Georg Thieme Verlag, 4th Edition,
Stuttgart 1985, Vol. E5, p. 1444 et se~., and the literature
cited therein.
Process I):
20 ~alogenation of a 3-(4-cyanophenyl)uracil of the formula I where
R3 is hydrogen
N ~ o R1
~ Y 0~ R3 Y OR4
I (R3=H) I (R3=halogen)
The halogenation is generally carried out in an inert organic
solvent or diluent. Suitable substances for the chlorination and
35 bromination are, for example, aliphatic carboxylic acids, such as
acetic acid, or chlorinated aliphatic hydrocarbons, such as
methylene chloride, chloroform and carbon tetrachloride.
Low-boiling aliphatic carboxylic acids, such as acetic acid, are
particularly preferred for the iodination.
Particularly suitable for the chlorination and bromination are
elemental chlorine or bromine, or sulfuryl chloride and sulfuryl
bromide, respectively, at from preferably O to 60 C, in particular
10 to 30 C.
CA 022l0909 l997-07-30
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28
If desired, the chlorination and bromination can be carried out
in the presence of an acid binder, in which case sodium acetate
and tertiary amines, such as triethylamine, dimethylaniline and
pyridine, are particularly preferred.
A particularly preferred iodinating agent is elemental iodine,
the reaction temperature in this case being from approximately 0
to 110 C, preferably from 10 to 30 C.
lO Particularly advantageous is the iodination in the presence of a
mineral acid, such as fuming nitric acid.
The amount of halogenating agent is not critical; equimolar
amounts of halogenating agent or an excess of up to 200 mol%
15 based on the precursor to be halogenated are generally used.
Excess iodine can be removed for example after the reaction by
means of saturated aqueous sodium hydrogen sulfite solution.
20 Process K):
Substitution of the nitro group of
3-(4-cyano-3-nitrophenyl)uracils VI by a group -oR4:
~ \ ~ CN
R3 Y NO2 R3 Y oR4
VI
35 The substitution of the nitro group iB generally carried out by
reacting VI with an alcoholate MoR4 where M i~ 8 metal atom,
preferably lithium, sodium or potassium (cf., for example,
Org.Synth. Coll. Vol. III, 293).
~O As a rule, the process is either carried out in the alcohol HoR4
whose alcoholate is used, or in an inert organic solvent or
- diluent, eg. in an aromatic hydrocarbon, such as toluene and the
xylenes, in an ether, such as diethyl ether, tetrahydrofuran and
1,2-dimethoxyethane, or in a halogenated hydrocarbon, such as
45 dichloromethane and chlorobenzene.
CA 02210909 1997-07-30
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29
The reaction temperature is generally at from 0 to 150 C,
preferably from room temperature (approximately 20 C) to the
boiling point of the reaction mixture in question.
5 The amount of alcoholate is generally not critical; approximately
1 to 3 equivalents of alcoholate per mole of VI are preferred.
The 3-(4-cyano-3-nitrophenyl)uracils V, in turn, can be obtained
for example from 3-(4-halo-3-nitrophenyl)uracils VII
A o Rl
R2 ~ N ~ ~ halogen VII
R3 Y N02
by substituting the halogen by cyano. The information given for
process H) apply analogously.
The 3-(4-halo-3-nitrophenyl)uracils VII, in turn, can be prepared
for example by nitrating 3-(4-halophenyl)uracils VIII
A o Rl
N ~/ ~
R2 ~ N ~ halogen VIII
R3 Y
using nitric acid, nitrating acid, an inorganic nitrate, such as
sodium nitrate, potassium nitrate and ammonium nitrate, or an
organic nitrate, such as amyl nitrate.
35 Suitable solvents for the nitration are, preferably, inorganic
acids, such as nitric acid and sulfuric acid, organic acids, such
as acetic acid, or anhydrides, such as acetic anhydride.
The reaction temperature is usually at from (-20) to 50 C,
40 preferably from (-10) to 30~C.
The amount of nitrating agent i8 not critical; it is usually one
to 10 times the molar amount based on the amount of VI.
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~ '
Process L):
Conversion of 3-(4-aminophenyl)uracils IX into compounds I by the
Sandmeyer method:
A o R1
~ ~ NH2 1 ) d azotization~ I
R3 Y oR4
IX
In this type of reaction, a procedure is generally followed in
which the amino group is converted into the diazonium salt in a
manner known per se, and this diazonium salt is subsequently
15 reacted with a metal cyanide, preferably lithum cyanide, sodium
cyanide or potassium cyanide, in the presence of a transition
metal catalyst, in particular copper(I) salt, expediently
copper(I) cyanide.
20 As regards the process conditions, reference may be made, for
example, to the information given in C. Ferri, ~'Reaktionen der
organischen Chemie" [Reactions in Organic Chemistryl, Georg
Thieme Verlag, Stuttgart 1978, p. 319, and in Organic Synthesis
Coll. Vol 1, p. 514 (1941).
The starting compounds IX can preferably be prepared by reducing
the corresponding nitro compounds using hydrogen in the presence
of a metal catalyst composed of Raney nickel, palladium or
platinum, or using a reducing agent, eg. a tin(II) salt or iron.
30 Further information on this reaction, which is known per se, can
be found, for example, in DE-A 37 24 399.
The nitrated precursors corresponding to the compounds IX, in
turn, can expediently be obtained by nitrating phenyl compounds X
A\ ~ o R
R2~<N ~ X
R3 Y oR4
The information given for the nitration of the
3-(4-halophenyl)uracils VII in process K) applies analogously to
45 the nitration of the phenyluracils X.
CA 022l0909 l997-07-30
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31
Process M):
Direct cyanation of a phenyl compound X:
cyanation
X ~ I
The cyanation can be carried out in the absence of a solvent or
in an inert solvent or diluent, for example in an aliphatic,
cyclic or aromatic hydrocarbon, such as n-pentane, petroleum
lO ether and cyclohexane, an aliphatic or cyclic ether, such as
diethyl ether, tert-butyl methyl ether, dimethoxyethane and
tetrahydrofuran, an aliphatic or aromatic halohydrocarbon, such
as dichloromethane, chloroform, 1,2-dichloroethane and the
dichlorobenzenes, an alcohol, ~uch as ethanol, methanol and
15 tert-butanol, an amide, such as dimethylformamide and
n-methylpyrrolidone, or an amine, such as ammonia. Mixtures of
these are also suitable.
Suitable cyanide sources are alkyl thiocyanates, such as methyl
20 thiocyanate {cf., for example, Synth. C~ n. 20~ 71 (1990)}~
chlorosulfonyl isocyanate (cf., for example, Org. Synth. Coll.
Vol VI, p. 465), dicyan, chlorine cyanide and bromine cyanide,
and furthermore trichloroacetonitrile {cf., in this context,
Gazz. Chim. Ital. 122, 283 (1992)}.
The temperatures are usually at from (-20) to 150 C, preferably at
from ~-10)~C to the boiling point of the reaction mixture in
question.
30 The ratio of cyanating agent to IX is not critical; it is usually
at from 1:1 to 10:1.
Modifications of this reaction are described, inter alia, in
Houben-Weyl, "Methoden der Organischen Chemie" lMethods in
35 Organic Chemistryl, Georg Thieme Verlag, Vol. E5, 4th Edition,
Stuttgart 1985, p. 1447 et seq. and in the literature cited
therein.
Those starting compounds of the formulae VI, VII, VIII and IX
40 which are not known already can be prepared in a snner known per
se ~cf., for example, EP-A 255 047, EP-A 517 181 and
JP-A 05/025 143).
The enamine esters of the formula III are novel. They can also be
45 employed as herbicides.
CA 02210909 1997-07-30
0050/45615
They can be prepared by methods known per se, for example by one
of the following processes:
N)
R
~ A O Rl O
~ / N~ ~ \ ~--NH~ CN
H / \=~ R2--~\ OLl
R3 O oR4 ) \~ oR4
XI XII R3 O III
15 The process is preferably carried out under essentially anhydrous
conditions in an inert solvent or diluent, particularly
preferably in the presence of an acidic or basic catalyst.
Suitable solvents or diluents are, in particular, organic
20 solvents which can be mixed with water to give an azeotropic
mixture, for example aromatics, such as benzene, toluene and o-,
m- and p-xylene, halogenated hydrocarbons, such as methylene
chloride, chloroform, carbon tetrachloride and chlorobenzene,
aliphatic and cyclic ethers, such as 1,2-dimethoxyethane,
25 tetrahydrofuran and dioxane, or cyclohexane, but also alcohols,
such as methanol and ethanol.
Preferred suitable acidic catalysts are strong mineral acids,
such as sulfuric acid and hydrochloric acid,
30 phosphorus-containing acids, such as orthophosphoric acid and
polyphosphoric acid, organic acids, such as p-toluenesulfonic
acid, and acidic cation exchangers, such as "Amberlyst 15"
(Fluka).
35 Examples of suitable basic catalysts are metal hydrides, such as
sodium hydride, and, particularly preferably, metal alcoholates,
such as sodium methanolate and sodium ethanolate.
XI and the ~-ketoester XII are expediently employed in an
40 approximately stoichiometric ratio, or else the process is
carried out with a slight excess of one or the other component,
up to approximately 10 mol%.
An amount of catalyst of 0.5 to 2 mol% based on the amount of
45 precursor will usually suffice.
~ 0050/45615 CA 02210909 1997-07-30
~ '
33
In general, the reaction is carried out at from 60 to 120 C or, to
rapidly remove water which forms, preferably up to the.boiling
point of the reaction mixture.
5 0):
oL2 A o Rl
R ~ OLl + N ~ ~ CN III
oR4
XIII XII
L2 is C1-C4-alkyl or phenyl.
This reaction can be carried out, for example, in an inert
20 organic solvent which is miscible with water, for example an
aliphatic or cyclic ether, such as 1,2-dimethoxyethane,
tetrahydrofuran and dioxane, or a lower alcohol, in particular
ethanol, the reaction t~l,erature usually being at from 50 to
100 C, preferably at the boiling point of the reaction mixture.
However, the reaction can also be carried out in an aromatic
diluent, such as benzene, toluene and o-, m- or p-xylene, in
which case an addition of either an acidic catalyst, such as
hydrochloric acid and p-toluenesulfonic acid, or of a base, eg.
30 an alkali metal alcoholate, such as sodium methanolate and sodium
ethanolate, is recommended. In this process variant, the reaction
temperature is usually again at from 50 to 100 C, but preferably
at from 60 to 80~C.
35 With regard to the weight ratios, the information given for
method N) applies.
CA 02210909 1997-07-30
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34
P):
A~ Rl
NH ~--
R2 ~ OLl + OCN CN ~ III
R3 O oR4
XIV XV
The reaction i8 expediently carried out in the presence of an
e6sentially anhydrous aprot$c organic solvent or diluent, for
15 example an aliphatic or cyclic ether, such as diethyl ether,
1,2-dimethoxyethane, tetrahydrofuran and dioxane, an aliphatic or
aromatic hydrocarbon, such as n-hexane, ben2ene, toluene and o-,
m- or p-xylene, a balogenated, aliphatic hydrocarbon, such a~
methylene chloride, chloroform, carbon tetrachloride,
20 1,2-dichloroethane and chlorobenzene, an aprotic, polar solvent,
such as dimethylfo. ~id~, hexamethylphosphoric triamide and
dimethyl sulfoxide, or a mixtures of these.
If desired, the process can also be carried out in the presence
25 of a metal hydride base, such as sodium hydride and potassium
hydride, or an organic tertiary base, such as triethylamine and
pyridine, it being possible for the organic base to act
simultaneously as the solvent.
30 It is expedient to employ the precursors in a stoichiometric
ratio or with a slight excess of one or the other components of
up to approximately 10 mol%. If the process is carried out in the
absence of a solvent and in the presence of an organic base, the
latter will be present in a larger excess.
The reaction temperature is preferably at from ~-80) to 50 C, in
particular at from (-60) to 30~C.
In a particularly preferred embodiment, the enamine ester III
40 obtained is converted directly (ie. "in situ") into the
corresponding desired product I in accordance with process A),
using an excess of base.
CA 02210909 1997-07-30
0OSO/45615
Q ) :
A~ ~ R
N H L30 ~/ \~
R2 ~oLl + N~ CN ~ III
oR4
R3 O
XIV XVI
L3 is Cl-C4-alkyl or phenyl.
This reaction is expediently carried out in an aprotic, polar
15 solvent or diluent, such as dimethylformamide, 2-butanone,
dimethyl sulfoxide and acetonitrile, advantageously in the
presence of a base, for example an alkali metal alcoholate or
alkaline earth metal alcoholate, in particular a sodium
alkanolate, such as sodium methanolate, an alkali metal carbonate
20 or alkaline earth metal carbonate, in particular sodium
carbonate, or an alkali metal hydride, such as lithium hydride
and sodium hydride.
Once to twice the molar amount of base, based on the amount of
25 XIV or XVI, will usually suffice.
The reaction temperature is generally at from 80 to 180 C,
preferably at the boiling point of the reaction mixture.
30 As regards the weight ratios of the starting compounds, the
information given for method N) applies.
In a particularly preferred embodiment, a sodium alcoholate is
used as the base, and the alcohol which forms in the course of
35 the reaction is continuously distilled off. The enamine esters
III prepared in this manner can be cyclized without isolation
from the reaction mixture in accordance with process A) to give a
salt of the ~ubstituted 3-(4-cyanophenyl)uracil~ I.
CA 02210909 1997-07-30
0050/45615
36
R)
NC0 ~
R2 ~ OLl + H2N ~ CN ~ ~ III
R3 0 oR4
XVII XVIII
This reaction is expediently carried out in the presence of an
essentially anhydrous aprotic organic solvent or diluent, for
15 example an aliphatic or cyclic ether, such as diethyl ether,
1,2-dimethoxyethane, tetrahydrofuran and dioxane, an aliphatic or
aromatic hydrocarbon, such as n-hexane, benzene, toluene and o-,
m- or p-xylene, a halogenated, aliphatic hydrocarbon, such as
methylene chloride, chloroform, carbon tetrachloride,
20 1,2-dichloroethane and chlorobenzene, an aprotic, polar solvent,
such as dimethylformamide, hexamethylphosphoric triamide and
dimethyl sulfoxide, or a mixtures of these.
If desired, the process can also be carried out in the presence
25 of a metal hydride base, such as sodium hydride and pota~sium
hydride, an alkali metal alcoholate or alkaline earth metal
alcoholate, such as sodium methanolate, ~odium ethanolate and
potassium tert-butanolate, or an organic nitrogen base, such as
triethylamine and pyridine, it being po~sible for the organic
30 base to act simultaneously as the solvent.
It is expedient to employ the precursors in a stoichiometric
ratio or with an excess of one of the components of up to
approximately 20 mol%. If the process is carried out in the
35 absence of a solvent and in the presence of an organic base, the
latter is advantageously present in an even larger excess.
The reaction temperature i~ generally at from (-80) to 150 C,
preferably at from (-30) C to the boiling point of the reaction
40 mixture in question.
The enA ine carboxylates of the formula IV are also novel; they
too can be prepared in a manner known per se, for example from an
aniline derivative of the formula VIII by the following equation:
CA 02210909 1997-07-30
'' 0050/45615
~ '
37
(Eq. 1)
o Rl Rl
of C~3 ~ R4 ~ i
CH3
XIX XVIII XX
~Eq. 2)
O Rl A
R2 ~ OLl ~ Hl-COOLl (XXI)
~ ~ CN ~ XX ~ IV
oR4
XXI XVIII
The reaction in accordance with equation 1 i8 preferably carried
25 out in an anhydrous inert aprotic solvent, for example in a
halogenated hydrocarbon, such a~ methylene chloride, chloroform,
carbon tetrachloride and chlorobenzene, an aromatic hydrocarbon,
such as benzene, toluene and o-, m- or p-xylene, or an aliphatic
or cyclic ether, such as diethyl ether, dibutyl ether,
30 1,2-dimethoxyethane, tetrahydrofuran and dioxane.
For the reaction of XIX with XVIII in accordance with equation
(Eq. 1), the reaction temperature is generally at from
approximately 70 to 140~C, in particular from 100 to 120~C.
The reaction in accordance with equation (Eq. 2) is an
aminolysis, which iB generally carried out either in the absence
of a solvent [cf., for example, J. Soc. Dyes Col. 42, (1926), 81,
Ber. 64, (1931), 970; Org. Synth., Coll. Vol. IV, (1943), 80 and
40 J.A.C.S. 70, (1948), 2402] or in an inert anhydrous
solvent/diluent, in particular an aprotic solvent, for example in
an aromatic, such as toluene and o-, m- or p-xylene, or a
halogenated aromatic, such as chlorobenzene.
CA 02210909 1997-07-30
'' 0050/45615
~ .
38
It is recommended to carry out the process in the presence of a
basic catalyst, for example a higher-boiling amine [see, for
example, Helv. Chim. Acta 11, (1928), 779 and U.S. 2,416,738] or
pyridine.
The reaction temperature is preferably at from approximately 130
to 160 C.
In both reactions {(Eq. 1) and (Eq. 2)}, the starting compounds
10 are expediently employed in approximately stoichiometric amounts,
or else the process is carried out with a slight excess of one or
the other component of up to approximately 10 mol%. If the
process is carried out in the presence of a basic catalyst, an
amount of 0.5 to 2 mol% of catalyst based on the amount of one of
15 the educts will usually suffice.
The subsequent reaction of the resulting compounds of the formula
XX with the amine XXI i8 advantageously carried out in an
es~entially anhydrous solvent~diluent under atmospheric pressure,
20 particularly preferably in the presence of an acidic catalyst.
It is advisable to prepare enamine carboxylates IV where A is
amino by employing compounds XXI having a protected amino group
(for example in the form of a hydrazone).
Suitable solvents/diluents are, in particular, organic liquids
which can be mixed with water to given an azeotropic mixture, for
example aromatics, such as benzene, toluene and o-, m- or
p-xylene, or halogenated hydrocarbons, such as carbon
30 tetrachloride and chlorobenzene.
Suitable catalysts are, in particular, strong mineral acids, such
as sulfuric acid, organic acids, such as p-toluenesulfonic acid,
phosphorus-cont~ n ~ ng acids, such as orthophosphoric acid and
35 polyphosphoric acid, or acidic cation exchangers, such as
"Amberlyst 15" (Fluka).
The reaction temperature is generally at from approximately 70 to
150 C; however, to rapidly remove the water of reaction which
40 forms it is expedient to carry out the process at the boiling
point of the reaction mixture in question.
Unless otherwise specified, all processes described above are
expediently carried out under atmospheric pressure or under the
45 inherent pressure of the reaction mixture in question.
CA 02210909 1997-07-30
0050/45615
~. ~
3g
Working-up of the reaction mixtures is generally carried out by
methods known per se, for example by removing the solvent,
partitioning the residue in a mixture of water and a suitable
organic solvent and working up the organic phase to obtain the
5 product.
The 3-(4-cyanophenyl)uracils of the formula I can have one or
more chiral centers, in which case they are usually obt~ine~ as
enantiomer or diastereomer mixture~. If desired, the mixtures can
10 be ~eparated into the essentially pure isomers by customary
methods, for example by means of crystallization or
chromatography on an optically active adsorbate. Pure optically
active isomers can, for example, also be prepared from the
corresponding optically active starting materials.
3-(4-Cyanophenyl)uracils I where A is hydrogen can be converted
into their salts, prefera~ly their alkali metal salts, in a
manner known per se (cf., in this context, also preparation
method b)).
Salts of I whose metal ion is other than an alkali metal ion can
be prepared in the customary manner by double decomposition of
the corresponding alkali metal salt, and ammonium, phosphonium,
sulfonium and sulfoxonium salts by means of ammonia, phosphonium
25 hydroxides, sulfonium hydroxides or sulfoxonium hydroxides.
The compounds I and their agriculturally useful salts, in the
form of the isomer mixtures and of the pure isomers, are suitable
as herbicides. The herbicidal compositions comprising I provide
30 very effective control of vegetation on non-crop areas,
particularly at high application rates. They act against
broad-leaved weeds and grass weeds in crop~ such as wheat, rice,
maize, soybeans and cotton without damaging the crop plants
considerably. Thi~ effect is particularly pronounced at low
35 application rates.
Depending on the application method in question, the compounds I
or the herbicidal compositions comprising them can additionally
be used in a further number of crop plants for eliminating
40 undesirable plants. Suitable crops are, for example, the
following:
Allium cepa, Ananas comosus, Arachi~ hypogaea, Asparagus
officinalis, Beta vulgaris ssp. altissima, Beta vulgaris ssp.
rapa, Brassica napus var. napus, Brassica napus var.
45 napobrassica, Brassica rapa var. silvestris, Camellia sinensis,
Carthamus tinctorius, Carya illinoinensis, Citrus limon, Citrus
sinen~is, Coffea arabica (Coffea canephora, Coffea liberica),
CA 02210909 1997-07-30
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Cucumis sativus, Cynodon dactylon, Daucus carota, Elaeis
guineensis, Fragaria vesca, Glycine max, Gossypium hirsutum,
(Gossypium arboreum, Gossypium herbaceum, Gossypium vitifolium),
Helianthus annuus, Hevea brasiliensis, Hordeum vulgare, Humulus
5 lupulus, Ipomoea batatas, Juglans regia, Lens culinaris, Linum
usitatissimum, Lycopersicon lycopersicum, Malus spp., Manihot
esculenta, Medicago sativa, Musa spp., Nicotiana tabacum
(N.rustica), Olea europaea, Oryza sativa , Phaseolus lunatus,
Phaseolus vulgaris, Picea abies, Pinus Bpp ., Pisum sativum,
10 Prunus avium, Prunus persica, Pyrus communis, Ribes sylvestre,
Ricinus communis, Saccharum officinarum, Secale cereale, Solanum
tuberosum, Sorghum bicolor (S. vulgare), Theobroma cacao,
Trifolium pratense, Triticum aestivum, Triticum durum, Vicia
faba, Vitis vinifera and Zea mays.
In addition, the compounds I can also be used in crops which
tolerate the action of herbicides as a result of breeding,
including genetic engineering methods.
20 Moreover, the 3-(4-cyanophenyl)uracils I are also suitable for
the desiccation and/or defoliation of plants.
As desiccants, they are particularly suitable for desiccating the
aerial parts of crop plants such as potatoes, oilseed rape,
25 sunflowers and soybeans. This allows completely mechanical
harvesting of these important crop plants.
Al~o of economic interest i~ facilitating harvesting, which is
made possible by concentrating, over a period of time, the drop
30 or the reduction of adhesion to the tree of citrus fruit, olives
or other species and varieties of pomaceous fruit, stone fruit
and shell fruit. The same mechanism, ie. promotion of the
formation of abscission tissue between fruit or leaf and shoot of
the plants, is also essential for the targeted controllable
35 defoliation of economic plants, in particular cotton.
Moreover, shortening the period of time within which the
individual cotton plants mature results in an increased fiber
quality post-harvest.
The compounds I, or the compositions comprising them, can be
applied, for example, in the form of-ready-to-spray aqueous
solutions, powders, suspensions, also highly concentrated aqueous
oily or other suspensions or dispersions, emulsions, oil
45 dispersions, pastes, dust~, materials for spreading, or granules,
by means of spraying, atomizing, dusting, scattering or pouring.
The use forms depend on the intended purposes; in any case, they
0050/45615 CA 022l0909 l997-07-30
41
should guarantee the finest possible distribution of the active
ingredients according to the invention.
Suitable inert additives for the preparation of ready-to-spray
5 solutions, emulsions, pastes or oil dispersions are essentially:
mineral oil fractions of medium to high boiling point, such as
kerosene and diesel oil, furthermore coal tar oils and oils of
vegetable or animal origin, aliphatic, cyclic and aromatic
hydrocarbon~, eg. paraffins, tetrahydronaphthalene, alkylated
10 naphthalenes and their derivatives, alkylated benzenes and their
derivatives, alcohols, such as methanol, ethanol, propanol,
butanol and cyclohexanol, ketones, such as cyclohexanone,
strongly polar solvents, eg. amines, such as N-methylpyrrolidone,
and water.
Aqueous use forms can be prepared from emulsion concentrates,
suspensions, pastes, wettable powders or water-dispersible
granules by adding water. To prepare emulsions, pastes or oil
dispersions, the substrates, either as such or dissolved in an
20 oil or solvent, can be homogenized in water by means of a wetting
agent, tackifier, dispersant or emulsifier. Alternatively, it is
possible to prepare concentrates comprising active ingredient,
wetting agent, tackifier, dispersant or emulsifier and, if
desired, solvent or oil, and these concentrates are suitable for
25 dilution with water.
Suitable surfactants (adjuvants) are the alkali metal salts,
alkaline earth metal salts and ammonium salts of aromatic
sulfonic acids, eg. ligno-, phenol-, naphthalene- and
30 dibutylnaphthalenesulfonic acid, or-of fatty acids, alkyl- and
alkylaryl sulfonate~, alkyl, lauryl ether and fatty alcohol
sulfates, and salts of sulfated hexa-, hepta- and octadecanols,
and also of fatty alcohol glycol ethers, condensates of
sulfonated naphthalene and its derivatives with formaldehyde,
35 condensates of naphthalene or of the naphthalenesulfonic acids
with phenol and formaldehyde, polyoxyethylene octylphenol ether,
ethoxylated isooctyl-, octyl- or nonylphenol, alkylphenyl
polyglycol ethers, tributylphenyl polyglycol ether, alkylaryl
polyether alcohols, isotridecyl alcohol, fatty alcohol/ethylene
40 oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl
ethers or polyoxypropylene alkyl ethers, lauryl alcohol
polyglycol ether acetate, sorbitol esters, lignosulfite waste
li~uors or methylcellulose.
CA 02210909 1997-07-30
0050/45615
g2
Powders, materials for spreading and dusts can be prepared by
mixing or grinding the active ingredients together with a solid
carrier.
5 Granules, eg. coated granules, impregnated granules and
homogeneous granules, can be prepared by binding the active
ingredients to solid carriers. Solid carriers are mineral earths,
such as silicas, silica gels, silicates, talc, kaolin, limestone,
lime, chalk, bole, loess, clay, dolomite, diatomaceous earth,
10 calcium sulfate, magnesium sulfate, magnesium oxide, ground
synthetic materials, fertilizers, such as ammonium sulfate,
ammonium phosphate, ammonium nitrate, urea, and products of
vegetable origin, such as cereal meal, tree bark meal, wood meal
and nutshell meal, cellulose powder, or other solid carriers.
The concentrations of the active ingredients I in the
ready-to-use products can be varied within wide ranges. In
general, the formulations comprise from 0.001 to 98% by weight,
preferably from 0.01 to 95% by weight, of active ingredient. The
20 active ingredients are employed in a purity of from 90% to 100%,
preferably 95% to 100% (in accordance with NMR spectrum).
The formulation examples which follow illustrate the preparation
of such products:
I. 20 parts by weight of Compound No. I.01 are dissolved in a
mixture composed of 80 parts by weight of alkylated
benzene, 10 parts by weight of the adduct of 8 to 10 mol of
ethylene oxide to 1 mol of oleic acid N-monoethanolamide, 5
parts by weight of calcium dodecylbenzenesulfonate and 5
parts by weight of the adduct of 40 mol of ethylene oxide
to 1 mol of castor oil. Pouring the solution into 100,000
parts by weight of water and finely distributing it therein
gives an aqueous dispersion comprising 0.02% by weight of
the active ingredient.
II. 20 parts by weight of Compound No. I.02 are dissolved in a
mixture composed of 40 parts by weight of cyclohexanone, 30
parts by weight of i~obutanol, 20 parts by weight of the
adduct of 7 mol of ethylene oxide to 1 mol of isooctyl
phenol and 10 parts by weight of the adduct of 40 mol of
ethylene oxide to 1 mol of castor oil. Pouring the solution
into 100,000 parts by weight of water and finely
distributing it therein gives an aqueous dispersion
comprising 0.02% by weight of the active ingredient.
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III. 20 parts by weight of the active ingredient No. I.03 are
dissolved in a mixture composed of 25 parts by weight of
cyclohexanone, 65 parts by weight of a mineral oil fraction
of boiling point 210 to 280 C and 10 parts by weight of the
adduct of 40 mol of ethylene oxide to 1 mol of castor oil.
Pouring the solution into 100,000 parts by weight of water
and finely distributing it therein gives an aqueous
dispersion comprising 0.02~ by weight of the active
ingredient.
IV. 20 parts by weight of the active ingredient No. I.04 are
mixed thoroughly with 3 parts by weight of sodium
diisobutylnaphthalene-a-sulfonic acid, 17 parts by weight
of the sodium salt of a lignosulfonic acid from a sulfite
waste liquor and 60 parts by weight of pulverulent silica
gel, and the mixture is ground in a hA -r mill. Finely
distributing the mixture in 20,000 parts by weight of water
gives a spray mixture comprising 0.1% by weight of the
active ingredient.
V. 3 parts by weight of the active ingredient No. I.05 are
mixed with 97 parts by weight of finely divided kaolin.
This gives a dust comprising 3~ by weight of the active
ingredient.
VI. 20 parts by weight of the active ingredient No. I.06 are
mixed intimately with 2 parts by weight of calcium
dodecylbenzenesulfonate, 8 parts by weight of fatty alcohol
polyglycol ether, 2 parts by weight of the sodium salt of a
phenol/urea/formaldehyde condensate and 68 parts by weight
of a paraffinic mineral oil. This gives a stable oily
dispersion.
VII. 1 part by weight of Compound No. I.07 is dissolved in a
mixture composed of 70 parts by weight of cyclohexanone,
20 parts by weight of ethoxylated isooctylphenol and
10 parts by weight of ethoxylated castor oil. This gives a
stable emulsion concentrate.
40 VIII. 1 part by weight of Compound No. I.08 is dissolved in a
mixture composed of 80 parts by weight of cyclohexanone and
20 parts by weight of Emulphor EL1). This gives a stable
emulsion concentrate.
45 1) ethoxylated castor oil
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The active ingredients I, or the herbicidal compositions, can be
applied pre- or post-emergence. If the active ingredients are
less well tolerated by certain crop plants, application
techniques may be used where the herbicidal compositions are
5 sprayed, with the aid of the spraying equipment, in such a way
that the active ingredients come into as little contact as
possible with the leaves of the sensitive crop plants while
reaching the leaves of undesirable plants which grow thereunder,
or the naked soil surface (post-directed, lay-by).
The application rates of active ingredient I are from 0.001 to
3.0, preferably 0.01 to 1, kg of active ingredient (a.i.) per ha,
depending on the desired control, the season, the target plants
and the growth stage.
To widen the spectrum of action and to achieve synergistic
effects, the 3-(4-cyanophenyl)uracils I may be mixed with a large
number of representatives of other groups of herbicidal or
growth-regulating active ingredients and then applied
20 concomitantly. Suitable components for mixtures are, for example,
1,2,4-thiadiazoles, 1,3,4-thiadiazoles, amides, aminophosphoric
acid and derivatives thereof, aminotriazoles, anilides,
aryloxy-/hetaryloxyalkanoic acids and derivatives thereof,
benzoic acid and derivatives thereof, benzothiadiazinones,
25 2-(hetaroyl/aroyl)-1,3-cyclohexanediones, heteroaryl aryl
ketones, benzylisoxazolidinones, meta-CF3-phenyl derivatives,
carbamates, quinolinecarboxylic acid and derivatives thereof,
chloroacetanilides, cyclohexane-1,3-dione derivatives, diazines,
dichloropropionic acid and derivatives thereof, dihydrobenzo-
30 furans, dihydrofuran-3-one, dinitroanilines, dinitrophenols,
diphenyl ethers, dipyridylium compounds, halocarboxylic acids and
derivatives thereof, ureas, 3-phenyluracils, imidazoles,
imidazolinones, N-phenyl-3,4,5,6-tetrahydrophthalimides,
oxadiazoles, oxiranes, phenols, aryloxy- and
35 heteroaryloxyphenoxypropionic esters, phenylacetic acid and
derivatives thereof, 2-phenylpropionic acid and derivatives
thereof, pyrazoles, phenylpyrazoles, pyridazines,
pyridinecarboxylic acid and derivatives thereof, pyrimidyl
ethers, sulfonamides, sulfonylureas, triazines, triazinones,
40 triazolinones, triazolecarboxamides and uracils.
It may furthermore be advantageous to apply the compounds I,
alone or in combination with other herbicides, together with
further crop protection agents, for example with pesticides or
45 agents for controlling pests, phytopathogenic fungi or bacteria.
Also of interest is the miscibility with mineral salt solutions,
which are employed for treating nutrient and trace element
' ' 0050/45615 CA 02210909 1997-07-30
deficiencies. Nonphytotoxic oils and oil concentrates may also be
added.
Preparation Examples
Example 1
3-[4-Cyano-3-methoxyphenyl]-6-trifluoromethyl-1,2,3,4-tetrahydro-
pyrimidine-2,4-dione (Comp. 1.01)
10 Sodium methanolate solution (2.8 g of a 30 percent strength
solution in methanol) was added to a solution of
3-[4-cyano-3-nitrophenyl]-6-trifluoromethyl-l~2~3~4-tetrahydro-
pyrimidine-2,4-dione (2.4 g) in 50 ml of anhydrou~ methanol. The
reaction mixture was subsequently refluxed for 5 hours. After
15 cooling, water (50 ml) was added first, followed by 10~ strength
aqueous hydrochloric acid to a pH of 3-4. The precipitate formed
was 6ubsequently separated off, washed with water and petroleum
ether and dried. Yield: 1.1 g; m.p.: >230 C.
20 Example 2
1-Amino-3-[4-cyano-3-methoxyphenyl]-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (Comp. 1.02)
Potassium carbonate (1.0 g) and 2,4-dinitrophenoxyamine (0.8 g)
25 were added to a solution of
3-[4-cyano-3-methoxyphenyl]-6-trifluoromethyl-1,2,3,4-tetrahydro-
pyrimidine-2,4-dione (1.1 g) in 15 ml of ethyl acetate. The
mixture was subsequently stirred for 15 hours at 55-60 C,
whereupon the solids formed were separated off and washed using
30 in each case 30 ml of ethyl acetate and diisopropyl ether. The
combined filtrate~ were washed twice using in each case 25 ml of
water, dried over sodium sulfate and then concentrated. After
crystallization using 10 ml of diisopropyl ether, 0.6 g of the
desired product was obtained. M.p.: >230 C.
Example 3
1-Amino-3-[4-cyano-3-hydroxyphenyll-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (Comp. 1.07)
40 1-Amino-3-[4-cyano-3-methoxyphenyl~-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (2.0 g) and pyridinium
hydrochloride (2.1 g) were stirred for 2 hours at 200-210 C. After
cooling, the reaction mixture was dissolved in 100 ml of
n-butanol, whereupon the solution was washed three times using in
45 each case 30 ml of water. The organic phase was dried over sodium
sulfate and ~ubsequently freed from solvent. After
crystallization using 10 ml of diisopropyl ether and
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chromatographic purification of the crude product ~eluent:
dichloromethane/ethyl acetate = 9:1 to 1:1~, 0.4 q of the desired
product was obtained. M.p.: > 230 C.
5 Example 4
3-~3-Allyloxy-4-cyanophenyl]-1-methyl-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (Comp. 1.08)
Potassium carbonate (4.6 g) and methyl iodide (2.1 ml, dissolved
10 in 20 ml of dimethylformamide) were added to a solution of
3-[3-allyloxy-4-cyanophenyl]-1-methyl-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (10.1 g) in 130 ml of
dimethylformamide. After the reaction mixture had been stirred
for 20 hours at room temperature, 150 ml of water were added,
lS whereupon the precipitate formed was separated off, washed with
water and petroleum ether and dried. Yield: 2.5 g;
m.p.: 158-160~C.
In addition to those mentioned above, other
20 3-(4-cyanophenyl)uracils I which were prepared, or can be
prepared, in a similar ~nner are listed in Table 2 below:
A o R1
R2 ~ N~ CN
R3 Y oR4
30 No. Y A Rl R2 R3 R4 M.p. [ Cl
1.01 o H H CF3 H CH3 >230
-1.02 ~ NH2 H CF3 H CH3 ~230
1.03 o H H CF3 H CH2CH=CH2 208-210
35 1.04 ~ NH2 H CF3 H CH2CHzCH2 177-179
1.05 ~ CH3 H CF3 H CH3 >230
1.06 O H H CF3 H CH(CH3)2 180-184
1.07 ~ NH2 H CF3 H H >230
40 1.08 ~ CH3 H CF3 H CH2CH=CH2 158-1600
l.09 ~ NH2 H CF3 H CH~CH3)2 185-187
l.10 o H H CF3 H C2Hs >2~0
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47
Preparation of the starting compounds:
Example 5
3-[4-cyano-3-nitrophenyl]-6-trifluoromethyl-1,2,3,4-tetrahydro-
5 pyrimidine-2,4-dione
Potassium carbonate (16.6 g) and potassium cyanide (7.8 g) were
added to a solution of
3-l4-fluoro-3-nitrophenyl]-6-trifluoromethyl-1,2,3,4-tetrahydro-
- 10 pyrimidine-2,4-dione (31.9 g) in 250 ml of anhydrous
N,N-dimethylformamide. The reaction mixture was subsequently
stirred for a total of 45 hours at 75-80 C, with two further
additions of potassium cyanide (in total 4.6 g) since the
reaction had not proceeded completely. For working-up, water
15 (250 ml) was added to the reaction mixture after it had cooled.
The pH was subsequently brought to 2-3 by adding 60 ml of 1 N
hydrochloric acid. After nitrogen had been passed through the
mixture for 4 hours to expel the hydrocyanic acid which had been
liberated, the precipitate formed was separated off, washed with
20 water and petroleum ether and dried. Yield: 17.0 g; m.p.: 135 C.
Example 6
3-[4-Cyano-2-fluoro-5-nitrophenyll-1-methyl-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (Comp. 8.2)
Potassium cyanide (0.5 g) was added to a solution of
3-12,4-difluoro-5-nitrophenyl]-1-methyl-6-trifluoromethyl-
1,2,3,4-tetrahydropyrimidine-2,4-dione (2.5 g) in 50 ml of
anhydrous dimethyl sulfoxide. The reaction mixture was
30 subsequently stirred for 10 hours at room temperature, more
potassium cyanide (0.16 g) being added after 5 hours. For
working-up, most of the solvent was removed at 80 C under a high
vacuum. The residue was taken up in lS0 ml of water, washed three
times using in each case 30 ml of water, dried over Rodium
35 sulfate and concentrated. Chromatography on silica gel
(dichloromethane aR eluent) and crystallization using petroleum
ether gave 1.2 g of the de~ired product; m.p.: 155-157 C.
The following compounds of Table 3 were prepared in a similar
40 manner:
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48
R2 ~ CN VIII
R3 Y NO2
No. y A Rl R2 R~ M.p. [ C]
10 8.1 O H H CF3 H 135
8.2 ~ CH3 F CF3 H 155-157
8.3 O H F CF3 H 135-137
Use Examples (herbicidal activity)
The herbicidal action of the 3-(4-cyanophenyl)uracils I was
demonstrated by the following greenhouse experiments:
The culture containers used were plastic flower pots containing
20 loamy sand with approximately 3.0% of humus as the substrate. The
seeds of the test plants were sown separately for each species.
In the case of the pre-emergence treatment, the active
ingredients, which were suspended or emulsified in water, were
25 applied directly after sowing by means of finely distributing
nozzles. The containers were irrigated gently to promote
germination and growth and subsequently covered with translucent
plastic hoods until the plants had rooted. This cover results in
uniform germination of the test plants, unless this was adversely
30 affected by the active ingredients.
For the post-emergence treatment, the test plants were first
grown to a plant height of 3 to 15 cm, depending on the growth
form, and only then treated with the active ingredients which
35 were suspended or emulsified in water. The test plants were
either sown directly and grown in the same containers, or grown
separately as seedlings and transplanted to the test containers a
few days prior to treatment. The application rate for the
post-emergence treatment was 0.0156 or 0.0078 kg of a.i. (active
40 ingredient) per ha.
The plants were kept at from 10-25 C or 20-35 C, depending on the
species. The test period extended to 2 - 4 weeks. During this
time, the plants were tended and their response to individual
45 treatments was evaluated.
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49
Evaluation was carried out using a scale from 0 to 100. 100 means
no emergence of the plants, or complete destruction of at least
the aerial parts, and 0 means no damage or normal course of
growth.
s
The plants used for the greenhouse experiments were the following
species:
Scientific Name Common Name
Abutilon theophrasti velvet leaf
Galium aparine catchweed bedstraw
Ipomoea subspecies morningglory
Solanum nigrum black nightshade
At an application rate of 0.0156 or 0.0078 kg of a.i./ha,
compound No. I.02 was very effective against the abovementioned
plants when used post-emergence.
20 Use examples (desiccant/defoliant activity)
The test plants used were young cotton plants with 4 leaves
(without cotyledons) which had been grown under greenhouse
conditions (relative atmospheric humidity 50 to 70%; day/night
25 temperature = 27/20~C).
The young cotton plants underwent foliar treatment to runoff
point with aqueous preparations of the active ingredients (with
an addition of 0.15% by weight of the fatty alcohol alkoxylate
30 Plurafac LF 700 based on the spray mixture). The amount of water
applied was 1000 l/ha (converted). After 13 days, the number of
shed leaves and the degree of defoliation in % were deteL i~e~.
No leaves were shed in the untreated control plants.
