This invention relates to pyridinyloxy(pyrimidinyloxy)benzene derivatives, herbicidal compositions containing them as active ingredient and to methods of using the compounds to control undesirable vegetation.

BACKGROUND OF THE INVENTION 
This invention relates to certain pyridinyloxy-(pyrimidinyloxy)benzene 
derivatives which exhibit pre-emergence and post-emergence control of 
grasses and broadleaf weeds with safety to crops such as corn. More 
particularly, this invention relates to compounds such as 
5-chloro-2-[2-(5-chloropyridin-2-yloxy)-phenoxy]pyrimidine and to a 
process for their preparation. 
Australian Pat. No. 005412 (European patent application No. 79301533.0) to 
ICI Australia Ltd. discloses the following bis(pyrimidyloxy)benzene 
derivatives as pre-emergent and post-emergent herbicides. 
##STR1## 
wherein A, B, D and E are H, halogen, NO.sub.2, CN, CNS, HCO, SO.sub.3 H, 
alkoxysulphonyl, YR, COYR, alkyl, alkenyl, cycloalkyl, alkylcarbonyl, 
NH.sub.2, Ph, carbamoyl or sulphamoyl; 
Y is O or S; 
R is H, cation of inorganic or organic base; 
R.sub.1 -R.sub.6 are H, halogen, OH, NO.sub.2, CN, CNS, CO.sub.2 H, 
alkoxycarbonyl, alknyloxy, alkylthio, cycloalkyl, NH.sub.2, Ph, carbamoyl 
or sulphonyl; and 
W is O or S. 
Compounds represented by the following structure are included in the 
Australian Patent. 
##STR2## 
where X=Br or Cl. 
United Kingdom application No. 7843037 to Ciba-Geigy discloses and claims a 
process for preparing hydroxydiarylethers which can be used as 
intermediates for preparing (phenoxy-phenoxy)alkanecarboxylic acids which 
have herbicidal and plant growth regulating action. The process comprises 
reacting a diether in a polar aprotic solvent in the presence of 0.1 to 1 
mole of alkali per mole of diether to give a hydroxybenzene according to 
the following equation: 
##STR3## 
wherein 
R is an alkyl group of 1-4 carbon atoms or Cl; 
X is a phenyl group of the structure 
##STR4## 
or a 2-pyridinyl group or a 4-pyridinyl group of the structure 
##STR5## 
where R.sub.1 -R.sub.6 are H, alkyl, Ph, halogen, CF.sub.3, NO.sub.2 or 
CN. 
European patent application No. 78300378.3 assigned to ICI Australia 
Limited (priority Sept. 13, 1977, AU 162677) discloses 2-phenoxy and 
2-phenylthio pyrimidines and their use as pesticides. 
##STR6## 
A, B and D are H, halogen, hydroxy, nitro, cyano, thiocyano, optionally 
substituted alkyl, alkenyl, alkoxy, alkenyloxy, alkylthio, cycloalkyl, 
amino, phenyl, carboxy, alkoxycarbonyl, carbamoyl, sulfo, alkylsulfonyl or 
sulfamoyl; 
R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are H, halogen, nitro, 
cyano, thiocyano, formyl, optionally substituted alkyl, alkenyl, 
cycloalkyl, alkylcarbonyl, amino, phenyl, carbamoyl, sulfo, alkoxysulfonyl 
or sulfamoyl; and 
X is O or S. 
SUMMARY OF THE INVENTION 
The present invention relates to pyridinyloxy-(pyrimidinyloxy)benzene 
derivatives of Formula I, to herbicidal compositions containing them as 
active ingredient and to methods of using the compounds to control 
undesirable vegetation. 
##STR7## 
wherein 
A is H, NO.sub.2, F, Cl or Br; 
B is H, C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.6 alkenyl, halogen, 
NO.sub.2, CN, CHO, OR.sup.1, COR.sup.1, CO.sub.2 R.sup.1 or SCN; 
Q.sup.1 is O or S; 
Q.sup.2 is O or S; 
X is N or CH; 
W is H, C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.4 alkenyl, F, Cl, Br, 
NO.sub.2, CN, CF.sub.3 or CO.sub.2 R.sup.2 ; 
Z is H, C.sub.1 -C.sub.4 alkyl, C.sub.3 -C.sub.4 alkenyl, F, Cl, Br, 
NO.sub.2, CN, CO.sub.2 R.sup.3 or CF.sub.3 ; and 
R.sup.1, R.sup.2 and R.sup.3 are independently C.sub.1 -C.sub.4 alkyl. 
Preferred for their high level of activity and/or ease of synthesis are 
those compounds of Formula I wherein: 
A is H; 
B is H, Cl, CH.sub.3 or NO.sub.2 ; 
Q.sup.1 is O; 
Q.sup.2 is O; 
X is N or CH; 
W is F, Cl, Br, NO.sub.2 or CF.sub.3 ; and 
Z is F, Cl, Br or NO.sub.2. 
More Preferred for their higher level of activity and/or greater ease of 
synthesis are those compounds of the preferred group in which: 
A is H; 
B is H; 
W is Cl or NO.sub.2 ; and 
Z is Br, Cl or NO.sub.2. 
The following compounds are specifically preferred for their excellent 
herbicidal activity and/or greatest ease of synthesis: 
2,2'-[1,2-phenylenebis(oxy)]bis[5-chloropyridine]; 
5-bromo-2-[2-(5-chloropyridin-2-yloxy)phenoxy]pyrimidine; 
5-chloro-2-[2-(5-nitropyridin-2-yloxy)phenoxy]pyridine; 
5-chloro-2-[2-(5-chloropyridin-2-yloxy)phenoxy]pyrimidine; and 
5-chloro-2-[2-(5-nitropyridin-2-yloxy)phenoxy]pyrimidine. 
This invention also relates to an improved process for preparing 
ortho-(pyridin-2-yloxy)phenols comprising heating to a melt, under an 
inert atmosphere, a mixture of catechol and a halopyridine. 
DETAILED DESCRIPTION OF THE INVENTION 
Synthesis 
The compounds of Formula I can be prepared by several different routes, 
depending on the particular substituents desired in the positions occupied 
by X, W and Z. 
Compounds of Formula I, wherein the substituents W and Z are different, can 
be made according to Equation 1. An appropriately substituted catechol 
(Q.sup.1,Q.sup.2 =O), dimercaptobenzene (Q.sup.1,Q.sup.2 =S), or 
mercaptophenol (Q.sup.1 =S,Q.sup.2 =O) of Formula II is allowed to react 
with an equimolar amount of a pyridine of Formula III wherein Y is a 
leaving group such as chlorine, bromine, alkylsulfonyl, or iodine to give 
a pyridin-2-yloxyphenol (Q.sup.2 =O), pyridin-2-ylthiophenol (Q.sup.2 =O) 
or a mercaptan of Formula IV. 
##STR8## 
The condensation is generally carried out in the presence of an alkali 
material such as sodium hydroxide, potassium hydroxide, sodium carbonate, 
potassium carbonate, sodium methoxide, or potassium t-butoxide. However, 
the pyridin-2-yloxyphenol IV can also be obtained by simply heating the 
catechol of Formula II and an equimolar amount of the pyridine of Formula 
III as a melt. 
Suitable solvents for this reaction include dimethylformamide, 
dimethylsulfoxide, sulfolan, dimethylacetamide, methyl ethyl ketone, and 
methyl isobutyl ketone. The reaction is preferably carried out at a 
temperature in the range of about 25.degree. C. to 150.degree. C. and a 
reaction time of about 1 to 24 hours. Usually, heating facilitates the 
reaction. 
The present invention includes the improved process for preparing an 
ortho-(pyridin-2-yloxy)phenol of Formula VI from catechol and a 
2-chloropyridine, such as 2,5-dichloropyridine, by heating the ingredients 
as a melt at about 150.degree. C. under nitrogen, no alkaline material or 
cosolvent being necessary. 
##STR9## 
The pyridin-2-yloxyphenol (Q.sup.2 =O) or mercaptan (Q.sup.2 =S) of Formula 
IV can then be allowed to react with a preferably equimolar amount of the 
pyrimidine (X=N) or pyridine (X=CH) of Formula V, wherein Y is a leaving 
group such as chlorine, bromine, alkylsulfonyl, or iodine to yield the 
bis(pyridinyloxy)-benzenes, pyridinylthio(pyrimidinyloxy)benzenes, 
bis(pyridinylthio)benzenes, or pyridinylthio(pyrimidinyloxy)benzenes of 
Formula I. The condensation is generally carried out in the presence of an 
alkali material such as sodium hydroxide, potassium hydroxide, sodium 
carbonate, or potassium carbonate. Appropriate solvents for the reaction 
include dimethylformamide, ethyl methyl ketone, acetonitrile, 
dimethylsulfoxide, sulfolan, dimethylacetamide, or methyl isobutyl ketone. 
Preferably, the reaction is carried out at a temperature in the range of 
about 25.degree. C. to 150.degree. C. and a reaction time of about 1 to 24 
hours. 
An alternative method of synthesizing compounds of Formula I wherein X=N is 
shown in Equation 2. A suitably substituted catechol (Q.sup.1,Q.sup.2 =O), 
dimercaptobenzene (Q.sup.1,Q.sup.2 =S), or mercaptophenol (Q.sup.1 
=S,Q.sup.2 =O) of Formula II is allowed to react with an equimolar amount 
of a pyrimidine of Formula IX, wherein Y is a leaving group such as 
chlorine, bromine, alkyl sulfonyl, or iodine to yield a 
pyrimidin-2-yloxyphenol (Q.sup.2 =O) or mercaptan (Q.sup.2 =S) of Formula 
X. Ordinarily, the reaction is carried out in the presence of an alkali 
material such as sodium hydroxide, potassium hydroxide, sodium carbonate, 
potassium carbonate, or sodium hydride and a suitable solvent such as 
dimethylformamide, dimethylsulfoxide, or methyl ethyl ketone. The 
temperature of the reaction can be in the range of about 25.degree. C. to 
150.degree. C. with a reaction time of about 1 to 24 hours. 
Subsequently, the pyrimidinyloxyphenol, pyrimidinylthiophenol, or the 
corresponding mercaptan of Formula X is combined with a pyridine of 
Formula III to yield the pyrimidinyloxy or pyrimidinylthiobenzene of 
Formula VIII as illustrated in Equation 2. 
##STR10## 
With compounds of Formula I, wherein X=CH, Q.sup.1 and Q.sup.2 =0, and the 
substituents W and Z are the same, the reaction outlined in Equation 3 can 
also be used in their synthesis. An appropriately substituted catechol of 
Formula XI and two equivalents of the pyridine of Formula XII are heated 
as a melt under nitrogen with hydrogen chloride being driven off. As a 
result, the bis(pyridin-2-yloxy)benzenes of Formula XIII can be obtained 
directly. 
##STR11## 
The 2-halopyridines and 2-halopyrimidines used in these reactions can be 
prepared by methods known in the art (See for example, "The Pyrimidines" 
Heterocyclic Compounds, Chapter VI (1962); "Pyrimidine and its 
Derivatives" Heterocyclic Compounds, Elderfield, Chapter 7 (1957); "The 
Pyridines" Heterocyclic Compounds, Part II, Chapter VI (1960)). 
As described in the Journal of Organic Chemistry 25, 1916 (1960), 
2,5-dichloropyrimidine can be made according to the following method: 
##STR12## 
By reacting with an aqueous solution of chlorine, 2-hydroxypyrimidine 
hydrochloride was converted to 2-hydroxy-5-chloropyrimidine. Heating the 
2-hydroxy-5-chloropyrimidine in excess phosphorous oxychloride gave 
2,5-dichloropyrimidine. 
Alternatively, 2-chloro-5-nitropyridine can be prepared using the procedure 
described in the Journal Chemical Society 9 (1941), starting with 
2-aminopyrimidine. Nitration of 2-aminopyridine gives 
2-amino-5-nitropyridine, which can be converted into 
2-hydroxy-5-nitropyridine by a diazonium reaction. Subsequent heating of 
2-hydroxy-5-nitropyridine in a phosphorous pentachloride/phosphorous 
oxychloride mixture yields 2-chloro-5-nitropyridine. The synthesis is 
summarized below: 
##STR13## 
Preparations of the substituted catechols used in these reactions can also 
be found in the art (Reactions of Catechols, Crown Zellerbach Corp., 
Bulletin, 1977). 
For example, chlorination of catechol with either chlorine or sulfuryl 
chloride, Berichte 44, 2182 (1911), C.A. 5, 3433 (1911) gives 
4-chlorocatechol as the major product, whereas excess halogen yields the 
4,5-dichlorocatechol. 
##STR14## 
Nitration of catechol can be carried out under various conditions to yield 
the 3- and 4-nitrocatechols (Journal Am. Chem. Soc., 75, 3277 (1953), 
Journal Chemical Society, 1088 (1971)).

The following examples illustrate the preparation of the compounds of this 
invention. Unless otherwise indicated, temperatures are in .degree.C. 
EXAMPLE 1 
2-(5-Chloropyridin-2-yloxy)phenol 
Under nitrogen, a mixture of 15.0 grams (0.136 mole) of catechol, and 22.0 
grams of 2,5-dichloropyridine was heated as a melt at 
140.degree.-150.degree. for 12 hours. The resulting black residue was 
dissolved in a minimum amount of methylene chloride, i.e., about 50 ml, 
chromatographed through a silica gel column using methylene chloride as 
the eluent. The 2-(5-chloropyridin-2-yloxy)phenol was isolated in the 
latter fraction, whereas starting material 2,5-dichloropyridine eluted 
with the solvent front. Yield 8.0 grams, m.p. 97.degree.-100.degree.; NMR 
(CDCl.sub.3): .delta.6.70-7.70 (m's, ArH and OH), 8.0 (d, ArH); ir 
(Nujol): 3.20-2.80 (OH), 6.30 (C=N), 13.30 microns. 
EXAMPLE 2 
2,2'-[1,2-Phenylenebis(oxy)]bis[5-chloropyridine] 
A mixture of 3.0 grams (0.027 mole) catechol and 9.0 grams (0.06 mole) 
2,5-dichloropyridine was heated as a melt under nitrogen for 7 hours at 
175.degree. followed by heating at 200.degree. for 5 hours. The black 
residue was dissolved in a minimum amount of methylene chloride and 
chromatographed through a silica gel column using methylene chloride as 
the eluent. From the initial fractions, the desired product was isolated. 
Yield 1.5 g, m.p. 82.degree.-84.degree.; NMR (CDCl.sub.3): .delta.6.70 (d, 
2H, ArH), 7.30 (s, 4H, ArH), 7.60 (AB quartet, 2H, ArH), 8.05 (d, 2H, 
ArH); ir (Nujol): 6.30 (C=N), 9.90, 11.95, 13.10 microns. 
EXAMPLE 3 
2,2'-[4-Methyl-1,2-phenylenebis(oxy)]bis[5-chloropyridine] 
In 40 ml of dimethylformamide, a mixture of 4.0 grams (0.032 mole) 
4-methylcatechol, 12.0 grams 2,5-dichloropyridine, and 12.0 grams of 
potassium carbonate was heated between 140.degree. and 145.degree. 
overnight. To the reaction mixture at room temperature was added excess 
H.sub.2 O and the resulting aqueous mixture was extracted with ethyl ether 
(200 ml) which was washed with H.sub.2 O (2X), saturated NaHCO.sub.3, 
brine, dried (MgSO.sub.4), filtered, and the solvent evaporated to yield 
an oil. Chromatography on a silica gel column using 1-chlorobutane as the 
eluent gave 5.0 grams of a white solid, m.p. 87.degree.-90.degree.; ir 
(Nujol): 6.30 (C=N), 9.10, 12.25 microns; NMR (CDCl.sub.3): .delta.2.35 
(s, 3H, CH.sub.3), 6.60 (d, 2H, pyridine ring protons), 7.00 (broads, 3H, 
ArH), 7.45 (AB quartet, 2H, pyridine ring protons), 7.95 (d, 2H, pyridine 
ring protons). 
EXAMPLE 4 
5-Chloro-2-[2(5-nitropyridin-2-yloxy)phenoxy]pyridine 
A mixture of 1.5 grams (0.0068 mole) 2-(5-chloropyridin-2-yloxy)phenol, 1.3 
grams 2-chloro-5-nitropyridine, 1.0 grams potassium carbonate, and 40 ml 
of methyl ethyl ketone was heated at reflux overnight. Excess water was 
added and the aqueous mixture extracted with 200 ml of ethyl ether. The 
ether extract was washed with saturated NaHCO.sub.3, H.sub.2 O, brine, 
dried (MgSO.sub.4), filtered, and the solvent was evaporated to yield a 
solid which was suspended in hexane and filtered. Yield 1.4 grams, m.p. 
82.degree.-84.degree.; ir (Nujol): 6.15, 6.25 (C=N, NO.sub.2), 13.30 
(broad), 13.70 microns; NMR (CDCl.sub.3): .delta.6.55 (s, ArH), 6.75 (d, 
ArH), 6.95 (s, ArH), 7.35 (s, 4H, ArH), 7.40-7.65 (m, ArH), 8.05 (d, ArH), 
8.40 (AB quartet, ArH), 8.95 (d, ArH). 
Following the teachings of Examples 1, 2, 3 and 4 and by using the 
appropriately substituted catechols and pyridines, the title compounds in 
Table I can be prepared. 
TABLE I 
__________________________________________________________________________ 
Bis(Pyridinyloxy)Benzenes 
##STR16## 
A B W Z 
__________________________________________________________________________ 
H H Cl Br 
H H Br Br 
H H NO.sub.2 Br 
H H NO.sub.2 NO.sub.2 
H H CN CN 
H H Cl CN 
H H Cl F 
H H F F 
H H Cl CF.sub.3 
H H CF.sub.3 CF.sub.3 
H H H H 
H H Cl H 
H H NO.sub.2 CF.sub.3 
H H CH.sub.3 CH.sub.3 
H H Cl CH.sub.3 
H H Cl n-C.sub.4 H.sub.9 
H H Cl CH(CH.sub.3).sub.2 
H H n-C.sub.3 H.sub.7 
n-C.sub.4 H.sub.9 
H H Cl CH.sub.2 CHCH.sub.2 
H H CH.sub.2 CHCH.sub.2 
CH.sub.2 CHCH.sub.2 
H H Cl CH.sub.2 CHCHCH.sub.3 
H H CH.sub.2 CHCHCH.sub.3 
NO.sub.2 
H H Cl CO.sub.2 CH.sub.3 
H H CO.sub.2 CH.sub.3 
CO.sub.2 CH.sub.3 
H H CO.sub.2C.sub.4 H.sub.9 
Cl 
H H CN CO.sub.2C.sub.4 H.sub.9 
3-F H Cl Cl 
3-NO.sub.2 
H CN CN 
3-Cl H Cl Cl 
3-Br H NO.sub.2 NO.sub.2 
3 or 6-F 
H Cl NO.sub.2 
3 or 6-NO.sub.2 
H NO.sub.2 Br 
3 or 6-Cl 
H Cl NO.sub.2 
3 or 6-Br 
H CH.sub.3 NO.sub.2 
H 4-CH.sub.3 Cl Cl 
H 4-n-C.sub.4 H.sub.9 
Cl Cl 
H 4-CH.sub.2 CHCH.sub.2 
Cl Cl 
H 4-CH.sub.2 CHCHCH.sub.2 CH.sub.2 CH.sub.3 
Cl Cl 
H 4-Cl Br Br 
H 4-Br Cl Cl 
H 4-I Cl Cl 
H 4-NO.sub.2 Cl Cl 
H 3-CH.sub.3 Cl Cl 
H 4-CN NO.sub.2 NO.sub.2 
H 4-CHO CH.sub.3 CH.sub.3 
H 4-OCH.sub.3 Cl Cl 
H 4-OCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 
Cl Cl 
H 4-COCH.sub.3 Cl Cl 
H 3-COC(CH.sub.3).sub.3 
Cl Cl 
H 4-CO.sub.2 CH.sub.3 
CN CN 
H 4-CO.sub.2 C.sub.4 H.sub.9 
Cl Cl 
H 4-SCN Cl Cl 
4-Cl 5-Cl CH.sub.3 CH.sub.3 
4-NO.sub.2 
5-NO.sub.2 Cl Cl 
3-NO.sub.2 
4-NO.sub.2 Cl Cl 
H 4 or 5-CH.sub.3 
Cl NO.sub.2 
H 4 or 5-CH.sub.3 
Cl CF.sub.3 
H 3-CHO CH.sub.3 CH.sub.3 
H 3-NO.sub.2 CN CN 
3-NO.sub.2 
5-NO.sub.2 CH.sub.3 CH.sub.3 
H 4-C.sub.2 H.sub.5 
Cl Cl 
H 4-CH(CH.sub.3).sub.2 
Cl Cl 
__________________________________________________________________________ 
EXAMPLE 5 
2-(5-Chloropyrimidin-2-yloxy)phenol 
To a mixture of 6.0 grams (0.055 mole) catechol and 7.0 grams of potassium 
carbonate stirring in 45 ml of dimethylformamide, 7.0 grams of 
2,5-dichloropyrimidine was added and the mixture stirred at room 
temperature overnight followed by heating at 80.degree. for 4 hours. 
Excess water was added to the reaction mixture, and the aqueous mixture 
extracted with 300 ml of ethyl ether. The ether extract was washed with 
H.sub.2 O (2X), brine, dried (magnesium sulfate), filtered, and the 
solvent removed to yield a yellow oil which slowly crystallized. From a 
1-chlorobutane/cyclohexane mixture, the crude solid was recrystallized to 
give 6.0 grams of product, m.p. 131.degree.-139.degree.; ir (Nujol): 
2.90-3.30 (OH), 12.80, 13.30 microns. 
EXAMPLE 6 
5-Bromo-2-[2-(5-chloropyridin-2-yloxy)phenoxy]-pyrimidine 
To a mixture of 1.5 grams (0.0068 mole) 2-(5-chloropyridin-2-yloxy)phenol 
and 1.0 gram potassium carbonate stirring in 40 ml of methyl ethyl ketone, 
1.6 grams of 2-chloro-5-bromopyridine was added and the mixture heated at 
reflux overnight. After addition of excess H.sub.2 O to the reaction 
mixture and extraction with 200 ml of ethyl ether, the ether extract was 
washed with H.sub.2 O, saturated HaHCO.sub.3, brine, dried (MgSO.sub.4), 
filtered, and evaporated to yield a yellow oil which crystallized from a 
1-chlorobutane/cyclohexane mixture to give 1.3 grams of a white solid 
product, m.p. 93.degree.-95.degree.; ir (Nujol): 6.30 (C=N), 9,85, 10.45, 
10.90, 11.25, 11.85, 12.40, 12.80, 13.10(s) microns; NMR (CDCl.sub.3): 
.delta.6.70 (d, ArH), 7.30 (s, 4H, ArH), 7.45-7.65 (m, ArH), 8.0 (d, ArH), 
8.50 (s, 2H, pyrimidine ring protons). 
EXAMPLE 7 
5-Chloro-2-[2-(5-chloropyridin-2-yloxy)phenoxy]-pyrimidine 
With stirring, 1.80 grams (0.012 mole) of 2,5-dichloropyrimidine was added 
to a mixture of 2.0 grams (0.009 mole) 2-(5-chloropyridin-2-yloxy)phenol, 
1.5 grams potassium carbonate, and 40 ml of methyl ethyl ketone. After the 
addition, the mixture was heated at reflux overnight and then poured into 
excess H.sub.2 O. After extracting with 200 ml of ethyl ether, the extract 
was washed with saturated NaHCO.sub.3, H.sub.2 O, brine, dried 
(MgSO.sub.4), filtered, and evaporated to yield a yellow solid which was 
recrystallized from 1-chlorobutane to give 2.3 grams of product, m.p. 
108.degree.-111.degree.; ir (Nujol): 6.35, 6.50 (C=N), 13.20 microns; NMR 
(CDCl.sub.3): .delta.6.75 (d, 1H, pyridine ring proton), 7.35 (s, 4H, 
ArH), 7.65 (AB quartet, 1H, pyridine ring proton), 8.10 (d, 1H, pyridine 
ring proton), 8.55 (s, 2H, pyrimidine ring protons). 
EXAMPLE 8 
5-Chloro- 2-[2-(5-nitropyridin-2-yloxy)phenoxy]-pyrimidine 
After heating at reflux a mixture of 1.5 grams (0.0067 mole) 
2-(5-chloropyrimidin-2-yloxy)phenol, 1.2 grams potassium carbonate, 1.3 
grams 2-chloro-5-nitropyridine and 40 ml of methyl ethyl ketone, the 
reaction mixture was poured into excess H.sub.2 0 and the aqueous mixture 
extracted with ethyl ether (200 ml). The ether layer was washed with 
saturated NaHCO.sub.3, H.sub.2 O, brine, dried (MgSO.sub.4), filtered, and 
evaporated to yield 2.3 grams of a yellow-orange oil which was purified by 
silica gel column chromatography (CH.sub.2 Cl.sub.2 as the eluent). NMR 
(CDCl.sub.3): .delta.6.90 (d, 1H, pyridine ring proton), 7.35 (s, 4H, 
ArH), 8.25-8.50 (m, 1H, pyridine ring proton), 8.45 (s, 2H, pyrimidine 
ring protons), 8.95 (d, 1H, pyridine ring proton). 
Following the procedure of Examples 5, 6, 7 and 8 and using suitably 
substituted catechols, pyridines, and pyrimidines, the following 
pyrimidinyloxybenzenes were prepared. 
TABLE II 
__________________________________________________________________________ 
Pyrimidinyloxybenzenes 
##STR17## 
A B W Z 
__________________________________________________________________________ 
H H Cl H 
H H Cl NO.sub.2 
H H Br CN 
H H Cl CH.sub.3 
H H CN Cl 
H H H Cl 
H H NO.sub.2 Br 
H H F Cl 
H H Cl F 
H H Br Br 
H H Cl CF.sub.3 
H H CF.sub.3 Cl 
H H CH.sub.3 Cl 
H H CH.sub.2 CHCH.sub.2 
Cl 
H H Cl CHCHCH.sub.2 CH.sub.3 
H H Cl CH.sub.2 CHCH.sub.2 
H H Br n-C.sub.4 H.sub.9 
H H n-C.sub.4 H.sub.9 
Cl 
H H CH.sub.2 CHCHCH.sub.3 
Cl 
H H CO.sub.2 CH.sub.3 
Br 
H H Cl CO.sub.2 CH.sub.3 
H H CO.sub.2 C.sub.4 H.sub.9 
Cl 
H H Cl CO.sub.2 C.sub.4 H.sub.9 
H H CH(CH.sub.3).sub.2 
Cl 
3 or 6-F 
H Cl Cl 
3 or 6-NO.sub.2 
H NO.sub.2 Cl 
3 or 6-Cl 
H NO.sub.2 Cl 
3 or 6-Br 
H Cl Br 
3-NO.sub.2 
5-NO.sub.2 Cl Br 
3-NO.sub.2 
4-NO.sub.2 NO.sub.2 Cl 
4-Cl 5-Cl Cl Cl 
4-NO.sub.2 
5-NO.sub.2 NO.sub.2 Cl 
H 4 or 5-CH.sub.3 Cl Cl 
H 4 or 5-n-C.sub.4 H.sub.9 
Cl Cl 
H 4 or 5-CH.sub.2 CHCH.sub.2 
CF.sub.3 Cl 
H 4 or 5-CH.sub.2 CHCHCH.sub.2 CH.sub.2 CH.sub.3 
NO.sub.2 Cl 
H 4 or 5-Cl Br Br 
H 4 or 5-Br Cl Cl 
H 4 or 5-I NO.sub.2 Cl 
H 4 or 5-NO.sub.2 NO.sub.2 Br 
H 3 or 6-CH.sub.3 Cl Cl 
H 4 or 5-CN NO.sub.2 NO.sub.2 
H 4 or 5-CHO Cl Cl 
H 4 or 5-OCH.sub.3 
Cl Br 
H 4 or 5-OCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 
Cl Cl 
H 4 or 5-COCH.sub.3 
Cl Cl 
H 3 or 6-COCH(CH.sub.3).sub.3 
NO.sub.2 Br 
H 4 or 5-CO.sub.2 CH.sub.3 
Cl Cl 
H 4 or 5-CO.sub.2 C.sub.4 H.sub.9 
Cl Cl 
H 4 or 5-SCN Cl Cl 
H 4 or 5-CH.sub.3 NO.sub.2 Cl 
H 4 or 5-CH.sub.3 CF.sub.3 Cl 
H 3 or 6-CHO Cl Cl 
H 3 or 6-NO.sub.2 Cl Cl 
H 4 or 5-C.sub.2 H.sub.5 
Cl Cl 
H 4 or 5-CH(CH.sub.3).sub.2 
Cl Cl 
__________________________________________________________________________ 
EXAMPLE 9 
5-Chloro-2-[2-(5-chloropyridin-2-ylthio)phenoxy]-pyridine 
To a mixture of 3.0 grams (0.023 mole) of 2-mercaptophenol and 7.0 grams of 
potassium carbonate stirring in 50 ml of dimethylformamide, 9.0 grams of 
2,5-dichloropyridine is added and the stirred mixture heated at 
130.degree. overnight. After pouring into excess H.sub.2 O, the aqueous 
mixture is extracted with ethyl ether (200 ml) and the extract washed with 
H.sub.2 O, saturated NaHCO.sub.3, and brine, dried (MgSO.sub.4), filtered, 
and the solvent evaporated to give the crude product which is 
recrystallized from 1-chlorobutane. 
EXAMPLE 10 
5-Nitro-2-[2-(5-chloropyridin-2-ylthio)phenoxy]pyridine 
To a mixture of 3.0 grams (0.023 mole) of 2-mercaptophenol and 7.0 grams of 
potassium carbonate stirring in 50 ml of dimethylformamide, 4.0 grams of 
2,5-dichloropyridine is added and the mixture stirred overnight at room 
temperature. After stirring overnight, 4.0 grams of 
2-chloro-5-nitropyridine is added and the mixture is again stirred at room 
temperature overnight. Excess H.sub.2 O is then added to the reaction 
mixture and the aqueous mixture extracted with ethyl ether (200 ml), 
washed with saturated NaHCO.sub.3, H.sub.2 O, brine, dried (MgSO.sub.4), 
filtered, and evaporated to yield the crude product. 
By using the procedures described in Examples 9 and 10, the compounds 
listed in Table III can be prepared. 
TABLE III 
______________________________________ 
Pyridin-2-yloxy(pyridin-2-ylthio)benzenes 
##STR18## 
A B W Z 
______________________________________ 
H H Br Br 
H H NO.sub.2 NO.sub.2 
H H CN CN 
H H CF.sub.3 CF.sub.3 
H H Cl Br 
H H Cl H 
H H Cl F 
H H F Cl 
H H H Cl 
H H CH.sub.3 CH.sub.3 
H H NO.sub.2 Br 
H H Cl CO.sub.2 CH.sub.3 
H H CH.sub.2 CHCH.sub.2 
Cl 
H H Cl n-C.sub.4 H.sub.9 
3-NO.sub.2 
H Cl Cl 
3-Cl H Br Br 
3-Br H Cl Cl 
H 3-CHO Cl Cl 
H 4-CH.sub.3 Cl Cl 
H 4-Cl CH.sub.3 CH.sub.3 
H 4-Br Cl Cl 
H 4-CN Cl Cl 
H 4-CH.sub.2 CH.sub.3 
Cl Cl 
______________________________________ 
EXAMPLE 11 
5-Nitro-2-[2-(5-chloropyrimidin-2-ylthio)phenoxy]-pyridine 
At 0.degree., 4.0 grams (0.027 moles) of 2,5-dichloropyrimidine is added to 
a mixture of 3.0 grams (0.0023 mole) 2-mercaptophenol and 7.0 grams of 
potassium carbonate stirring in 50 ml of dimethylformamide. After stirring 
overnight at room temperature, 4.0 grams of 2-chloro-5-nitropyridine is 
added and the mixture is heated at 80.degree. for 4 hours. The reaction 
mixture is then poured into excess H.sub.2 O and extracted with ethyl 
ether (200 ml). Washing with H.sub.2 O, saturated NaHCO.sub.3, brine, 
drying (MgSO.sub.4), and evaporation yields the crude product. 
Following the procedure described in Example 11, the following compounds in 
Table IV may be prepared. 
TABLE IV 
______________________________________ 
Pyrimidin-2-yloxy(pyridin-2-ylthio)benzenes 
##STR19## 
A B W Z 
______________________________________ 
H H NO.sub.2 Br 
H H Cl Cl 
H H CF.sub.3 Br 
H H Cl NO.sub.2 
H H CN Cl 
H H CH.sub.3 CH.sub.3 
H H H Cl 
H H Cl F 
H H F Cl 
H H Cl CO.sub.2 CH.sub.3 
H H Cl CH.sub.2 CHCH.sub.2 
H H Cl CN 
3-NO.sub.2 
H Cl Cl 
3-Cl H CH.sub.3 CH.sub.3 
3-Br H Cl Cl 
H 3-CHO Cl Cl 
H 4-CH.sub.3 Cl Cl 
H 4-Cl NO.sub.2 NO.sub.2 
H 4-Br Cl Cl 
H 4-CH.sub.2 CH.sub.3 
Cl Cl 
H H H H 
______________________________________ 
EXAMPLE 12 
5-Chloro-2-[2-(5-nitropyridin-2-ylthio)phenoxy]-pyrimidine 
At 0.degree., 4.0 grams (0.025 moles) of 2-chloro-5-nitropyridine is added 
to a mixture of 3.0 grams (0.0023 mole) 2-mercaptophenol and 7.0 grams of 
potassium carbonate stirring in 50 ml of dimethylformamide. After stirring 
overnight at room temperature, 4.0 grams of 2,5-dichloropyrimidine is 
added and the mixture is heated at 80.degree. for 5 hours. The mixture is 
then poured into excess H.sub.2 O and the aqueous mixture is extracted 
with ethyl ether (200 ml), washed with saturated sodium bicarbonate, 
brine, dried (MgSO.sub.4), and the solvent is evaporated to yield the 
crude product. 
The procedure in Example 12 may be modified and used in preparing the 
compounds listed in Table V. 
TABLE V 
______________________________________ 
Pyridin-2-ylthio(pyrimidin-2-yloxy)benzenes 
##STR20## 
A B W Z 
______________________________________ 
H H NO.sub.2 Br 
H H Cl Cl 
H H Br Br 
H H Cl CH.sub.3 
H H CN CN 
H H Cl NO.sub.2 
H H CH.sub.3 CH.sub.3 
H H Cl H 
H H H Cl 
H H CF.sub.3 Cl 
H H Br CF.sub.3 
H H Cl CO.sub.2 CH.sub.3 
H H Cl CH.sub.2 CHCH.sub.2 
3-NO.sub.2 
H Cl Cl 
3-Cl H CH.sub.3 CH.sub.3 
3-Br H NO.sub.2 NO.sub.2 
H 3-CHO Cl Cl 
H 4-CH.sub.3 Cl Cl 
H 4-Cl Cl Cl 
H 4-Br CH.sub.3 CH.sub.3 
H 4-CH.sub.2 CH.sub.3 
Cl Cl 
H 4-CN Br Br 
H H H H 
______________________________________ 
EXAMPLE 13 
2,2'-[1,2-Phenylenebis(thio)]bis[5-chloropyridine] 
In 50 ml of stirred dimethylformamide, a mixture of 3.0 grams (0.02 mole) 
dimercaptobenzene, 7.0 grams potassium carbonate, and 7.0 grams of 
2,5-dichloropyridine is heated at 80.degree. for 5 hours. Thereafter 
pouring into excess H.sub.2 O, the mixture is extracted with ethyl ether 
(200 ml) and washed with H.sub.2 O, saturated NaHCO.sub.3, and brine, 
dried (MgSO.sub.4), and evaporated to yield the crude product which can be 
recrystallized from 1-chlorobutane. 
Example 13 illustrates the general procedure for preparing the compounds in 
Table VI. 
TABLE VI 
______________________________________ 
Bis(Pyridin-2-ylthio)benzenes 
##STR21## 
A B W Z 
______________________________________ 
H H Br Br 
H H CF.sub.3 CF.sub.3 
H H NO.sub.2 NO.sub.2 
H H CN CN 
H H CH.sub.3 CH.sub.3 
H H H H 
H H F F 
H H NO.sub.2 Cl 
H H Cl Br 
H H CF.sub.3 Cl 
H H NO.sub.2 CH.sub.3 
H H CO.sub.2 CH.sub.3 
Cl 
3-NO.sub.2 H Cl Cl 
3-Cl H Cl Cl 
3-Br H CH.sub.3 CH.sub.3 
H 3-CHO NO.sub.2 NO.sub.2 
H 4-CH.sub.3 Cl Cl 
H 4-Cl Cl Cl 
H 4-Br CH.sub.3 CH.sub.3 
H 4-CH.sub.2 CH.sub.3 
Cl Cl 
H 4-CN Cl Cl 
______________________________________ 
EXAMPLE 14 
5-Bromo-2-[2-(5-chloropyrimidin-2-ylthio)phenylthio]-pyridine 
To a mixture of 3.0 grams (0.02 mole) dimercaptobenzene and 7.0 grams of 
potassium carbonate stirring in 50 ml of dimethylformamide, 3.5 grams of 
2,5-dichloropyrimidine is added at 0.degree. and the mixture stirred for 4 
hours, before adding 5.0 grams of 2,5-dibromopyridine and heating at 
80.degree. for 4 additional hours. The mixture is added to excess H.sub.2 
O and extracted with ethyl ether. After washing the ether layer with 
H.sub.2 O, saturated NaHCO.sub.3, brine, and drying (MgSO.sub.4), 
evaporating the solvent gives the crude product. 
Following the procedure of Example 14, the compounds in Table VII may be 
prepared. 
TABLE VII 
______________________________________ 
Pyridin-2-ylthio(pyrimidin-2-ylthio)benzenes 
##STR22## 
A B W Z 
______________________________________ 
H H Cl Cl 
H H Br Br 
H H CH.sub.3 CH.sub.3 
H H CF.sub.3 Cl 
H H Cl CO.sub.2 CH.sub.3 
H H NO.sub.2 NO.sub.2 
H H Cl CN 
H H CN H 
H H H Cl 
H H F F 
H H CH.sub.3 Cl 
3-NO.sub.2 H Cl Cl 
3-Cl H CF.sub.3 Cl 
3-Br H Cl Cl 
H 3-CHO NO.sub.2 Cl 
H 4-CH.sub.3 Cl Cl 
H 4-Cl CH.sub.3 Cl 
H 4-Br Cl Cl 
H 4-CH.sub.2 CH.sub.3 
Cl Cl 
H 4-CN NO.sub.2 Br 
______________________________________ 
Formulations 
The compounds of this invention can be formulated in a variety of ways for 
use. For example, the compounds can be formulated as dusts, granules, 
pellets, solutions, suspensions, emulsions, wettable powders, emulsifiable 
concentrates and the like. Many of the formulations can be applied 
directly to the area of undesirable vegetation. Sprayable formulations, on 
the other hand, can be extended in suitable media and used at spray 
volumes of from a few liters to several hundred liters per hectare. High 
strength compositions are used primarily as intermediates for subsequent 
formulation. 
The formulations, according to this invention will ordinarily contain from 
about 0.1% to 80% by weight of active ingredient(s) and at least one of 
(a) about 0.1% to 20% surfactant(s) and (b) about 1% by 99.9% solid or 
liquid inert diluent(s). More specifically, they will contain these 
ingredients in the following approximate proportions: 
TABLE VIII 
______________________________________ 
Active* 
Inert 
Ingredient 
Diluent(s) 
Surfactant(s) 
______________________________________ 
Wettable Powders 
20-80 0-74 1-10 
Emulsions, Solutions, 
3-50 40-95 0-15 
(including Emulsifiable 
Concentrates) 
Aqueous Suspension 
10-50 40-84 1-20 
Dusts 1-25 70-99 0-5 
Granules and Pellets 
0.1-80 20-99.9 0-15 
______________________________________ 
*Active ingredient plus at least one of a Surfactant or a Diluent equals 
100 weight percent. 
Lower or higher levels of active ingredient can be used depending on the 
intended application and the physical properties of the compound. Higher 
ratios of surfactant to active ingredient are sometimes desirable, and the 
appropriate ration can be achieved by incorporating the surfactant into 
the formulation or by tank mixing. 
Typical solid diluents are described in Watkins, et al., "Handbook of 
Insecticide Dust Diluents and Carriers", 2nd Ed., Dorland Books, Caldwell, 
New Jersey, but other solids, either mined or manufactured, may be used. 
The more absorptive diluents are preferred for wettable powders and the 
denser ones for dusts. Typical liquid diluents and solvents are described 
in Marsden, "Solvents Guide," 2nd Ed., Interscience, New York, 1950. 
Solubility under 0.1% is preferred for suspension concentrates; solution 
concentrates are preferably stable against phase separation at 0.degree. 
C. "McCutcheon's Detergents and Emulsifiers Annula", MC Publishing Corp., 
Ridgewood, New Jersey, as well as Sisely and Wood, "Encyclopedia of 
Surface Active Agents", Chemical Publishing Co., Inc., New York, 1964, 
list surfactants and recommended uses. All formulations can contain minor 
amounts of additives to reduce foaming, caking, corrosion, microbiological 
growth, etc. 
The methods of preparing the formulations are well known. Solutions can be 
prepared by simply mixing the ingredients. Fine solid compositions are 
made by blending and, usually, grinding as in a hammer or fluid energy 
mill. Suspensions are prepared by wet milling (see, for example, Littler, 
U.S. Pat. No. 3,060,084). Granules and pellets may be made by spraying the 
active material upon performed granular carriers or by agglomeration 
techniques. See J. E. Browning, "Agglomeration", Chemical Engineering, 
December 4, 1967, pp. 147ff. and "Perry's Chemical Engineer's Handbook", 
5th Ed., McGraw-Hill, New York, 1973, pp. 8-57ff. 
In the following examples, all parts are by weight unless otherwise 
indicated. 
EXAMPLE 15 
______________________________________ 
Wettable Powder 
______________________________________ 
5-chloro-2-[2-(4-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 80% 
sodium alkylnaphthalenesulfonate 
2% 
sodium ligninsulfonate 2% 
synthetic amorphous silica 3% 
kaolinite 13% 
______________________________________ 
The ingredients are blended, hammer-milled until practically all the solids 
are under 50 microns and then reblended. 
EXAMPLE 16 
______________________________________ 
Wettable Powder 
______________________________________ 
5-chloro-2-[2-(5-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 50% 
sodium alkylnaphthalenesulfonate 
2% 
low viscosity methyl cellulose 
2% 
diatomaceous earth 46% 
______________________________________ 
The ingredients are blended, coarsely hammer-milled and then air-milled to 
produce particles of active substantially all below about 10 microns in 
diameter. The product is reblended before packaging. 
EXAMPLE 17 
______________________________________ 
Granule 
______________________________________ 
Wettable Powder of Example 16 
5% 
attapulgite granules 95% 
(U.S.S. 20-40 mesh; 0.84-0.42 mm) 
______________________________________ 
A slurry of wettable powder containing about 25% solids is sprayed on the 
surface of attapulgite granules in a double-cone blender. The granules are 
dried and packaged. 
EXAMPLE 18 
______________________________________ 
Extruded Pellet 
______________________________________ 
2,2'-[1,2-phenylenebis(oxy)]bis[5-chloro- 
pyridine] 25% 
anhydrous sodium sulfate 
10% 
crude calcium ligninsulfonate 
5% 
sodium alkylnaphthalenesulfonate 
1% 
calcium/magnesium bentonite 
59% 
______________________________________ 
The ingredients are blended, hammer-milled and then moistened with about 
12% water. The mixture is extruded as cylinders about 3 mm diameter which 
are cut to produce pellets about 3 mm long. These may be used directly 
after drying, or the dried pellets may be crushed to pass a U.S.S. No. 20 
sieve (0.84 mm openings). The granules held on a U.S.S. No. 40 sieve (0.42 
mm openings) may be packaged for use and the fines recycled. 
EXAMPLE 19 
______________________________________ 
Wettable Powder 
______________________________________ 
5-chloro-2-[2-(5-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 20% 
sodium alkylnaphthalenesulfonate 
4% 
sodium ligninsulfonate 4% 
low viscosity methyl cellulose 
3% 
attapulgite 69% 
______________________________________ 
The ingredients are thoroughly blended. After grinding in a hammer-mill to 
produce particles substantially all below about 100 microns, the material 
is reblended and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) and 
packaged. 
EXAMPLE 20 
______________________________________ 
Low Strength Granule 
______________________________________ 
2,2'-[1,2-phenylenebis(oxy)]bis[5-chloro- 
pyridine] 1% 
N,N--dimethylformamide 9% 
attapulgite granules 90% 
(U.S.S. 20-40 sieve) 
______________________________________ 
The active ingredient is dissolved in the solvent and the solution is 
sprayed upon dedusted granules in a double cone blender. After spraying of 
the solution has been completed, the blender is allowed to continue 
running for a short period, and then the granules are packaged. 
EXAMPLE 21 
______________________________________ 
Aqueous Suspension 
______________________________________ 
5-bromo-2-[2-(5-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 40% 
polyacrylic acid thickener 0.3% 
dodecylphenol polyethylene glycol ether 
0.5% 
disodium phosphate 1% 
monosodium phosphate 0.5% 
polyvinyl alcohol 1.0% 
water 56.7% 
______________________________________ 
The ingredients are blended and ground together in a sand mill to produce 
particles substantially all under 5 microns in size. 
EXAMPLE 22 
______________________________________ 
Low Strength Granule 
______________________________________ 
5-chloro-2-[2-(5-nitropyridin-2-yloxy)phenoxy]- 
pyridine 0.1% 
attapulgite granules 99.9% 
(U.S.S. 20-40 mesh) 
______________________________________ 
The active ingredient is dissolved in a solvent, and the solution is 
sprayed upon dedusted granules in a double-cone blender. After spraying 
has been completed, the material is warmed to evaporate the solvent. The 
material is allowed to cool and then packaged. 
EXAMPLE 23 
______________________________________ 
Granule 
______________________________________ 
5-chloro-2-[2-(5-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 70% 
wetting agent 1% 
crude ligninsulfonate salt (containing 
10% 
5-20% of the natural sugars) 
attapulgite clay 19% 
______________________________________ 
The ingredients are blended and milled to pass through a 100 mesh screen. 
This material is then added to a fluid bed granulator, the air flow is 
adjusted to gently fluidize the material, and a fine spray of water is 
sprayed onto the fluidized material. The fluidization and spraying are 
continued until granules of the desired size range are made. The spraying 
is stopped, but fluidization is continued, optionally with heat, until the 
water content is reduced to the desired level, generally less than 1%. The 
material is then discharged, screened to the desired size range, generally 
14-100 mesh (1410-149 microns), and packaged for use. 
EXAMPLE 24 
______________________________________ 
Wettable Powder 
______________________________________ 
5-bromo-2-[2-(5-chloropyridin-2-yloxy)phenoxy]- 
pyrimidine 40% 
sodium ligninsulfonate 20% 
montmorillonite clay 40% 
______________________________________ 
The ingredients are thoroughly blended, coarsely hammer-milled and then 
air-milled to produce particles substantially all below 10 microns in 
size. The material is reblended and then packaged. 
EXAMPLE 25 
______________________________________ 
Dust 
______________________________________ 
2,2'-[1,2-phenylenebis(oxy)]bis[5-chloro- 
pyridine] 10% 
attapulgite 10% 
Pyrophyllite 80% 
______________________________________ 
The active ingredient is blended with attapulgite and then passed through a 
hammer-mill to produce particles substantially all below 200 microns. The 
ground concentrate is then blended with powdered pyrophyllite until 
homogeneous. 
EXAMPLE 26 
______________________________________ 
Emulsifiable Concentrate 
______________________________________ 
5-chloro-2-[2-(5-nitropyridin-2-yloxy)phenoxy]- 
pyrimidine 20% 
chlorobenzene 74% 
sorbitan monostearate and polyoxyethylene 
condensates thereof 6% 
______________________________________ 
The ingredients are combined and stirred to produce a solution which can be 
emulsified in water for application. 
UTILITY 
The compounds of this invention are active herbicides. They have utility 
for broad-spectrum pre- and/or post-emergence weed control in areas where 
complete control of all vegetation is desired, such as around fuel storage 
tanks, ammunition depots, industrial storage areas, oil-well sites, 
drive-in theaters, around billboards, highway and railroad structures. By 
properly selecting rate and time of application, compounds of this 
invention may also be used to modify plant growth beneficially, and also 
to selectively control weeds in crops such as wheat, barley, sorghum, 
alfalfa, sunflower and corn. 
The precise amount of the compounds of Formula I to be used in any given 
situation will vary according to the particular end result desired, the 
amount of foliage present, the weeds to be controlled, the crop species 
involved, the soil type, the formulation and mode of application, weather 
conditions, etc. Since so many variables play a role, it is not possible 
to state a rate of application suitable for all situations. Ordinarily, 
the compounds of this invention can be used at levels of about 0.01 to 20 
kg/ha with a preferred range of 0.05 to 10 kg/ha. The higher rates from 
within this range are applied for particularly adverse conditions or where 
extended persistence in soil is desired. 
The compounds of Formula I may be combined with other herbicides and are 
particularly useful in combination with the ureas: such as 
3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron); the triazines: such as 
2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine); the 
uracils: such as 5-bromo-3-sec-butyl-6-methyluracil (bromacil); 
N-(phosphonomethyl) glycine (glyphosate); 
3-cyclohexyl-1-methyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione 
(hexazinone); N,N-dimethyl-2,2-diphenylacetamide (diphenamid); 
2,4-dichlorophenoxyacetic acid (2,4-D) (and closely related compounds); 
4-chloro-2-butynyl-3-chlorophenylcarbamate (barban); 
S-(2,3-dichloroallyl)-diisopropylthiocarbamate (diallate); 
S-(2,3,3-trichloroallyl-diisopropylthiocarbamate (triallate); 
1,2-dimethyl-3,5-diphenyl-1H-pyrazolium methyl sulfate (difenzoquat, 
methyl sulfate); methyl 2-[4-(2,4-dichlorophenoxy)-phenoxy]propanoate 
(diclofop methyl); 
4-amino-6-tert-butyl-3-(methylthio)-1,2,4-triazin-5-(4H)-one (metribuzin); 
3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron); 
3-isopropyl-1H-2,1,3-benzothiodiazin-4(3H)-one-2,2-dioxide (bentazon); 
.alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine 
(trifluralin); 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat); monosodium 
methanearsonate (MSMA); 2-chloro-2',6'-diethyl (methoxymethyl) acetanilide 
(alachlor); 1,1-dimethyl-3-(.alpha. 
,.alpha.,.alpha.-trifluoro-m-tolyl)-urea (fluometuron); and 
5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid, methyl ester 
(acifluorfen-methyl). 
The following examples further illustrate the herbicidal activity of the 
compounds of this invention. 
Test A 
Seeds of crabgrass (Digitaria spp.), barnyardgrass (Echinochloa crusgalli), 
wild oats (Avena fatua), cassia (Cassia tora), morningglory (Ipomoea sp.), 
cocklebur (Xanthium spp.), sorghum, corn, soybean, rice, wheat and 
nutsedge tubers (Cyperus rotundus) were planted in a growth medium and 
treated pre-emergence with the chemicals dissolved in a non-phytotoxic 
solvent. At the same time, cotton having five leaves (including 
cotyledonary ones), bush beans with the second trifoliate leaf expanding, 
crabgrass and barnyardgrass with two leaves, wild oats with one leaf, 
cassia with three leaves (including cotyledonary ones), morningglory and 
cocklebur with four leaves (including the cotylendonary ones), sorghum and 
corn with three leaves, soybean with two cotyledonary leaves, rice with 
two leaves, wheat with one leaf, and nutsedge with three to five leaves 
were sprayed. Treated plants and controls were maintained in a greenhouse 
for sixteen days, then all species were compared to controls and visually 
rated for response to treatment. 
The ratings are based on a numerical scale extending from 0=no injury, to 
10=complete kill. The accompanying descriptive symbols have the following 
meanings: 
G=growth retardation; 
C=chlorosis/necrosis; 
S=albinism; 
E=emergence inhibition; 
6Y=abscised buds or flowers; 
H=hormonal effects; and 
--=not rated. 
##STR23## 
TABLE A 
__________________________________________________________________________ 
Compound 1 
Compound 2 
Compound 3 
Compound 4 
Compound 5 
Compound 6 
Rate kg/ha 2 0.4 0.4 0.4 0.4 0.4 
__________________________________________________________________________ 
POST-EMERGENCE 
Bush bean 9S 2C 9S 9S 6S,6Y 8C 
Cotton 6S 4C 5S 4C,8G 3C,8G 8C 
Sorghum 3S 0 0 1C,5G 0 0 
Corn 2C 0 1S 7C 0 2C 
Soybean 8S 2C 5S 9S 2C,5G 3S,5G 
Wheat 1C 0 1C 3C 0 0 
Wild Oats 7C 0 1C 8S 0 0 
Rice 7S 0 0 5G 0 0 
Barnyardgrass 
9S 7S 5S 9S 2S 
2C 
Crabgrass 10S 5C 5S 9S 6S 5C 
Morningglory 
1S,5G 7C 7S 9C 0 7C 
Cocklebur 4S 2C 5S 6S 2C 6C 
Cassia 8S 4C 6S 5S,9G 2C 6C 
Nutsedge 3C 0 0 2S 0 0 
PRE-EMERGENCE 
Sorghum 9S 4S 9S 9S 5S 9S 
Corn 6S,9H 4S 9S 9S 5S 9S 
Soybean 5S 0 8S 8S 1C 8S 
Wheat 10S 4S 10S 10S 9S 9S 
Wild Oats 10S 6S 9S 10S 9S 9S 
Rice 8S 5S 9S 8S 6S 6S 
Barnyardgrass 
10S 10S 10S 10S 9S 10S 
Crabgrass 10S 9S 9S 10S 9S 9S 
Morningglory 
5S 0 6S 10S 0 10S 
Cocklebur 3C 0 0 2C 0 6G 
Cassia 10S 0 9C 10S 0 10S 
Nutsedge 5S 0 6C 6S 1C 3C 
__________________________________________________________________________ 
Test B 
Two plastic bulb pans were filled with fertilized and limed Fallsington 
silt loam soil. One pan was planted with corn, sorghum, Kentucky bluegrass 
and several grassy weeds. The other pan was planted with cotton, soybeans, 
purple nutsedge (Cyperus rotundus), and several broadleaf weeds. The 
following grassy and broadleaf weeds were planted: crabgrass (Digitaria 
sanguinalis), barnyardgrass (Echinochloa crusgalli), wild oats (Avena 
fatua), johnsongrass (Sorghum halepense), dallisgrass (Paspalum 
dilatatum), giant foxtail (Setaria faberii), cheatgrass (Bromus 
secalinus), mustard (Brassica arvensis), cocklebur (Xanthium 
pensylvanicum), pigweed (Amaranthus retroflexus), morningglory (Ipomoea 
hederacea), cassia (Cassia tora), teaweed (Sida spinosa), velvetleaf 
(Abutilon theophrasti), and jimsonweed (Datura stramonium). A 12.5 cm 
diameter plastic pot was also filled with prepared soil and planted with 
rice and wheat. Another 12.5 cm pot was planted with sugarbeets. The above 
four containers were treated pre-emergence with several test compounds 
within the scope of the invention. 
Twenty-eight days after treatment, the plants were evaluated and visually 
rated for response to the chemical treatments utilizing the rating system 
described previously for Test A. The data are summarized in Table B. It 
may be seen that certain compounds from within the scope of the invention 
have utility for selective pre-emergence weed control in crops such as 
wheat, sorghum and corn. 
TABLE B 
__________________________________________________________________________ 
PRE-EMERGENCE ON 
FALLSINGTON SILT LOAM SOIL 
Compound 1 
Compound 3 
Compound 6 
Compound 4 (Series I) 
Compound 4 (Series II) 
Rate kg/ha 
1/4 
1 1/8 
1/2 1/8 
1/2 1/32 
1/16 
1/4 
3/4 
1/8 1/2 
__________________________________________________________________________ 
Crabgrass 
10C 
10C 10C 
10C 9C 10C 9C 10C 
10C 
10C 
10C 10C 
Barnyardgrass 
10C 
10C 7C 10C 6C 10C 2C 10C 
10C 
10C 
9C 10C 
Sorghum 0 2C 0 0 2G 5C 0 0 5C 10C 
1C 7C 
Wild Oats 
0 6C 0 6C 2C 8C 0 2C 3C 10C 
4C 10C 
Johnsongrass 
4G 5C 3G 4C 2C 9C 0 3G 6C 9C 3C 8C 
Dallisgrass 
4C 8C 0 7C 3C 10C 3G 8C 10C 
10C 
5C 155 8C 
Giant Foxtail 
10C 
10C 4G 8C 4C 10C 6C 10C 
10C 
10C 
10C 10C 
Ky. bluegrass 
10E 
10E 7C 10C 6C 10C 6C 10C 
10C 
10C 
10C 10C 
Cheatgrass 
8E 6E,4C 
5E 10E 0 7C 5C 5C 5C 9C 0 7C 
Sugarbeets 
10C 
10C 10C 
10C 9C 10C 10C 
10C 
10C 
10C 
10C 10C 
Corn 0 3C 0 0 3G 0 0 0 0 0 0 2S 
Mustard 10C 
10C 10E 
10E 10C 
10C 0 0 0 0 0 2S 
Cocklebur 
0 0 0 0 0 3G 0 0 0 3G 0C 0 
Pigweed 9C 9C 10C 
10C 8C 10C 10C 
10C 
10C 
10C 
10C 10C 
Nutsedge 
0 0 0 0 0 0 0 0 0 0 0 1S 
Cotton 0 1C 0 3C 2C 5C 0 1C 5C 10C 
3C 10C 
Morningglory 
0 0 0 2G 0 10C 0 0 0 3G 0 1C 
Cassia 3C 7C 7C 10C 6C 10C 9C 10C 
10C 
10C 
10C 10C 
Teaweed 3C 9C 5C 8C 0 6C 3C 5C 9C 9C 5C 7C 
Velvetleaf 
10C 
10C 10C 
10C 10C 
10C 9C 10C 
10C 
10C 
10C 10C 
Jimsonweed 
3C 7C 2C 8C 0 3C 3C 5C 7C 7C 8C 8C 
Soybean 2C 5C 0 6C 2C 5C 0 4C 8C 9C 5C 9C 
Rice 3C 7C 0 4C 4C 5C 2C 6C 9C 9C 8C 9C 
Wheat 0 3C 0 2C 0 0 0 0 2C 4C 2C 3C 
__________________________________________________________________________ 
Test C 
Two ten-inch in diameter plastic pans lined with polyethylene liners were 
filled with prepared Fallsington silt loam soil. One pan was planted with 
seeds of wheat (Triticum aestivum), barley (Hordeum vulgare), wild oats 
(Avena fatua), downy brome (Bromus tectorum), cheatgrass (Bromus 
secalinus), blackgrass (Alopecurus myosuroides), annual bluegrass (Poa 
annua), green foxtail (Setaria viridis), quackgrass (Agropyron repens), 
Italian ryegrass (Lolium multiflorum) and ripgut brome (Bromus rigidus). 
The other pan was planted with seeds of Russian thistle (Salsola kali), 
tansy mustard (Descuraina pinnata), smartweed (Polygonum pensylvanicum), 
tumble mustard (Sisymbrium altissium) kochia (Kochia scoparia), shepherd's 
purse (Capsella bursa-pastoris), Matricaria inodora, black nightshade 
(Solanum nigrum), yellow rocket (Barbarea vulgaris), wild mustard 
(Brassica kaber) and wild buckwheat (Polygonum convolvulus). The above two 
pans were treated pre-emergence. At the same time two pans in which the 
above plant species were growing were treated post-emergence. Plant height 
at the time of treatment ranged from 1-15 cm depending on plant species. 
The compounds applied were diluted with a non-phytotoxic solvent and 
sprayed over-the-top of the pans. An untreated control and a solvent alone 
control were included for comparison. All treatments were maintained in 
the greenhouse for 20 days at which time the treatments were compared to 
the controls and the effects visually rated. The recorded data are 
presented in Table C. The potential utility of several of the compounds 
tested for pre- and/or post-emergence weed control in wheat and barley is 
evident. 
TABLE C 
__________________________________________________________________________ 
Compound 1 Compound 2 
Rate kg/ha 
1/2 1/16 1/4 1/16 1/4 
PRE-EMERGENCE 
POST-EMERGENCE 
PRE-EMERGENCE 
POST-EMERGENCE 
__________________________________________________________________________ 
Wheat 0 0 0 0 0 0 
Barley 1C,1G 1C,1G 0 0 0 0 
Wild Oats 
0 7C,6G 0 0 0 0 
Downy Brome 
5C,4G 6C,5G 0 0 2G 2C,5G 
Cheatgrass 
7C,6G 10C 0 0 2G 2C,4G 
Blackgrass 
10C 10C 0 0 0 1G 
Annual bluegrass 
10C 10C 2G 4C,5G 1C,4G 5C,6G 
Green foxtail 
10C 10C 1C,2G 
10C 2C,3G 10C 
Quackgrass 
10C 5C,6G 0 1G 1C,2G 2C,3G 
Italian ryegrass 
6C,4G 7C,7G 0 2G 0 3G 
Ripgut brome 
1G 0 0 0 0 0 
Russian thistle 
0 2G 0 0 0 1G 
Tansy mustard 
10C 10C 10C 10C 10C 10C 
Smartweed 
-- -- -- -- -- -- 
Tumble mustard 
10C 10C 2G 10C 10C 10C 
Kochia 10C 10C 0 1G 1C,2G 3C,7G 
Shepherd's purse 
10C 10C 2C,3G 
10C 10C 10C 
Matricaria inodora 
4C,2G 0 0 10C 2G 2C,4G 
Black nightshade 
10C 10C 0 2C,4G 2C,5G 7C,8G 
Yellow rocket 
10C 10C 2C,4G 
10C 10C 10C 
Wild mustard 
10C 10C 7C,5G 
10C 10C 10C 
Wild buckwheat 
10C 10C 5C,4G 
7C,8G 10C 10C 
__________________________________________________________________________ 
Test D 
Twenty-five cm diameter plastic pots filled with Fallsington silt loam were 
planted with soybeans, cotton, alfalfa, corn, rice, wheat, sorghum, 
sugarbeets, velvetleaf (Abutilon theophrasti), sesbania (Sesbania 
exaltata), Cassia (Cassia tora), morningglory (Ipomoea hederacea), 
jimsonweed (Datura stramonium), cocklebur (Xanthium pensylvanicum), 
crabgrass (Digitaria spp.), nutsedge (Cyperus rotundus), barnyardgrass 
(Echinochloa crusgalli), giant foxtail (Setaria faberii), mustard 
(Brassica arvensis), pigweed (Amaranthus retroflexus), sunflower 
(Helianthus annuus), and wild oats (Avena fatua). Approximately 21/2 weeks 
after planting, the young plants and the soil around them were sprayed 
overall with the test chemicals dissolved in a non-phytotoxic solvent. Two 
weeks after treatment, all species were compared to untreated controls and 
visually rated for response to treatment. The rating system was as 
described previously for Test A. The data are presented in Table D. 
Selected compounds from within the scope of the invention have utility for 
post-emergence weed control in alfalfa, corn, wheat, sorghum and 
sunflower. 
TABLE D 
______________________________________ 
Over-the-Top Soil/Foliage Treatment 
Compound 1 Compound 3 
Rate kg/ha 2 1/2 1 1/4 
______________________________________ 
Soybeans 9G,8C 9G,8C 10C 10C 
Velvetleaf 9G,9C 10C 10C 9G,7C 
Sesbania 10C 8G,8C 10S 9G,8C 
Cassia 10S -- 10C 10C 
Cotton 5G,5S 4G,3S 10C 10C 
Morningglory 10S 4G,4S 10C 10C 
Alfalfa 3C 0 5G,7S 2G,5S 
Jimsonweed 0 1S -- 7G 
Cocklebur -- 2S 6G,6S 4G,6S 
Corn 1G,2S 2S 4G,5S 3S 
Crabgrass 10C 5G,5C 10C 10C 
Rice 10S 5S 9S 5C 
Nutsedge 0 0 1C 4G 
Barnyardgrass 
10C 3C 10C 3G,4C 
Wheat 1G,3C 1C 1G 1G 
Giant foxtail 
5S 10S 8G,6S 2C 
Wild Oats 6G,6S 3S 6S 0 
Sorghum 1C 0 8S 2S 
Mustard 10S 9G,9S 10C 10C 
Pigweed -- -- -- -- 
Johnsongrass -- -- -- -- 
Sunflower 2S 2G,2S 8G,5C 3G,5S 
Sugarbeets 10S 10S 10C 10C 
______________________________________