A herbicidal compound of formula (I): ##STR1## wherein X is O, S(O).sub.n or NR.sup.a where R.sup.a is H or alkyl and n is 0, 1 or 2; PA1 R.sup.1 is H or halo; PA1 R.sup.2 is N or CR.sup.3 where R.sup.3 is halo or NO.sub.2 ; PA1 R.sup.4 is H, halo, NO.sub.2, alkyl, haloalkyl, CN, CO.sub.2 alkyl, cycloalkyl, phenyl, COalkyl, COphenyl, CHO,OH, NH.sub.2, NHCOalkyl or alkoxy PA1 R.sup.5 is H, halo or optionally substituted alkyl; PA1 R.sup.6 is H, halo or optionally substituted alkyl; provided that at least one of R.sup.5 and R.sup.6 is halo; PA1 R.sup.7 is CN, CHO, COOR.sup.8, CONR.sup.8 R.sup.9, where R.sup.8 is H, optionally substituted alkyl, alkenyl, alkynyl or aryl and R.sup.9 is a group R.sup.8, SO.sub.2 alkyl, NR.sup.10 R.sup.11 or N.sup.+ R.sup.10 R.sup.11 R.sup.12 Z.sup.- where Z is an agriculturally acceptable anion e.g. chloride and R.sup.10, R.sup.11 and R.sup.12 are independently selected from hydrogen and alkyl. Processes for the preparation of these compounds and compositions containing them are also described.

This invention relates to diphenyl ether derivatives useful as herbicides 
and to herbicidal compositions and processes utilizing them. 
The compounds have good herbicidal activity. 
According to the present invention there is provided a compound of formula 
(I) 
##STR2## 
wherein 
X is 0, S(O).sub.n or NR.sup.a where R.sup.a is H or alkyl and n is 0, 1 or 
2; 
R.sup.1 is H or halo; 
R.sup.2 is N or CR.sup.3 where R.sup.3 is halo or NO.sub.2 ; 
R.sup.4 is H, halo, alkyl, NO.sub.2, haloalkyl, CN, CO.sub.2 alkyl, 
cycloalkyl, phenyl, COalkyl, COphenyl, CHO, OH, NH.sub.2, NHCOalkyl, 
alkoxy; 
R.sup.5 is H, halo or optionally substituted alkyl; 
R.sup.6 is H, halo or optionally substituted alkyl, provided that at least 
one of R.sup.5 or R.sup.6 is halo; 
R.sup.7 is CN, COOR.sup.8, CHO, CONR.sup.8 R.sup.9, where R.sup.8 is H, 
optionally substituted alkyl, alkenyl, alkynyl or aryl and R.sup.9 is a 
group R.sup.8, SO.sub.2 alkyl NR.sup.10 R.sup.11 or N.sup.+ R.sup.10 
R.sup.11 R.sup.12 Z.sup.- where Z is an agriculturally acceptable anion 
e.q. chloride and R.sup.10, R.sup.11 and R.sup.12 are independently 
selected from hydrogen and alkyl. 
Suitable halo groups for R.sup.1 are fluoro and chloro, preferably fluoro. 
Suitable groups for R.sup.2 are CR.sup.3. 
Suitable halo groups for R.sup.3 are fluoro and chloro, preferably chloro. 
Suitable haloalkyl groups for R.sup.4 contain from 1 to 6 carbon atoms. A 
particular example is trifluoromethyl and pentafluoroethyl. 
As used herein the term "alkyl" includes straight or branched chains 
containing up to 10 carbon atoms preferably from 1 to 6 carbon atoms. The 
terms "alkenyl" and "alkynyl" refer to unsaturated straight or branched 
chains having from 2 to 10 and preferably from 2 to 6 carbon atoms. The 
term "aryl" includes phenyl. The term cycloalkyl includes rings containing 
from 3 to 9 carbon atoms, preferably from 3 to 6 carbon atoms. The term 
alkoxy includes straight or branched chain containing up to 10 carbon 
atoms preferably from 1 to 6 carbon atoms. 
Examples of optional substituents for alkyl groups R.sup.5, R.sup.6, 
R.sup.8 and R.sup.9, include one or more groups selected from halo such as 
fluoro, chloro or bromo; nitro; nitrile; aryl such as phenyl; CO.sub.2 
R.sup.13, NHCOR.sup.13 or NHCH.sub.2 CO.sub.2 R.sup.13 wherein R.sup.13 is 
hydrogen, C.sub.1-6 alkyl or an agriculturally acceptable cation; 
C.sub.1-6 alkoxy; oxo; amino; mono- or di- C.sub.1-6 alkylamino; 
CONR.sup.14 R.sup.15 wherein R.sup.14 and R.sup.15 are independently 
selected from hydrogen, C.sub.1-6 alkyl, C.sub.2-6 alkenyl or C.sub.2-6 
alkynyl or R.sup.14 and R.sup.15 are joined together to form a 
heterocyclic ring having up to 7 ring atoms; and heterocyclyl containing 
up to 10 ring atoms up to 3 of which may be selected from oxygen, nitrogen 
and sulphur. An example of a heterocyclic substituent for R.sup.5, 
R.sup.6, R.sup.8 and R.sup.9 is tetrahydrofuranyl. R.sup.4 is suitably 
hydrogen, bromo, chloro, nitro or cyano. 
Suitably, R.sup.5 and or/ R.sup.6 are fluoro. Preferably CR.sup.5 R.sup.6 
R.sup.7 is 
##STR3## 
or CF.sub.2 COOR.sup.8. Preferably R.sup.8 is C.sub.1-6 alkyl. 
The structural formula (I) given above is intended to include tautomeric 
forms of the structure drawn, as well as physically distinguishable 
modifications of the compounds which may arise, for example, from 
different ways in which the molecules are arranged in a crystal lattice, 
or from the inability of parts of the molecule to rotate freely in 
relation to other parts, or from geometrical isomerism, or from 
intra-molecular or inter-molecular hydrogen bonding, or otherwise. 
Some of the compounds of the invention can exist in enantiomeric forms. The 
invention includes both enantiomers and mixtures of the two in all 
proportions. 
Particular examples of compounds according to the invention are listed in 
Table I as well as other salts and zwitterions thereof. 
TABLE I 
__________________________________________________________________________ 
##STR4## 
COMPOUND CHARACTERISING 
NO. R.sup.1 
R.sup.3 
R.sup.4 
R.sup.5 
R.sup.6 
R.sup.7 X DATA 
__________________________________________________________________________ 
1 F Cl Cl H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(dd, 1H); 7.35(d, 1H); 
6.9(d, 1H); 6.6(dd, 1H); 
5.9(d, 1H); 4.4(q, 2H); 
1.35(t, 3H). 
2 F Cl NO.sub.2 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 8.02(d, 1H); 7.64 
(s, 1H); 7.5(dd, 1H); 
6.95(d, 1H); 6.75(dd, 1H) 
6.0(d, 1H); 4.4(q, 2H); 
1.4(t, 3H) 
3 F Cl Cl CH.sub.3 
F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(d, 1H); 7.3(d, 1H); 6.9 
(d, 1H); 6.6(dd, 1H); 4.2 
(q, 2H); 1.85(d, 3H); 
1.17(t, 3H) 
4 F Cl Br H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.5 
(d, 1H); 7.45(dd, 1H); 
6.9(d, 1H); 6.55(dd, 1H); 
5.9(d, 1H); 4.35(q, 2H); 
1,35(t, 3H) 
5 F Cl Cl H F COH O m.p. 95-96.degree. C. 
6 F Cl Cl H F CO.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.43 
(dd, 1H); 6.9(d, 1H); 6.6 
(dd, 1H); 6.35(d, 1H); 
5.95(d, 1H); 3.9(s, 3H). 
7 F Cl Cl H F CO.sub.2 (CH.sub.2).sub.3 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.43 
(dd, 1H); 7.35(d, 1H); 
6.9(d, 1H); 6.6(dd, 1H); 
5.9(d, 1H); 4.3(q, 2H); 
1.65(m, 2H); 1.4(m, 2H); 
0.95(t, 3H). 
8 F Cl Cl F F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(dd, 1H); 7.35(d, 1H), 
6.95(d, 1H); 6.7(dd, 1H); 
4.4(q, 2H); 1.35(t, 3H). 
9 F Cl Cl H F CON(CH.sub.3).sub.2 
O n.m.r. 7.6(s, 1H); 7.4 
(dd, 1H); 7.35(d, 1H); 
6.9(d, 1H); 6.55(dd, 1H); 
6.1(d, 1H); 3.1(d, 6H). 
10 F Cl H H F CO.sub.2 CH.sub.2 CH.sub. 3 
O n.m.r. 7.6(s, 1H); 7.4 
(d, 1H); 7.3(dd, 1H); 6.9 
(d, 1H); 6.7(dd, 2H); 5.9 
(d, 1H); 4.35(q, 2H); 1.35 
(t, 3H). 
11 H NO.sub.2 
Cl H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 8.25(s, 1H); 7.8 
(dd, 1H); 7.48(d, 1H); 7.12 
(d, 1H); 7.05(d, 1H); 6.85 
5.9(d, 1H); 4.4(q, 2H); 
1.35(t, 3H). 
12 H Cl Cl H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.75(s, 1H); 7.5 
(d, 1H); 7.4(d, 1H); 7.05 
(d, 1H); 6.95(d, 1H); 
6.75(dd, 1H); 5.9(d, 1H); 
4.4(q, 2H); 1.35(t, 3H). 
13 Cl 
Cl H H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.7(s, 2H); 7.25 
(dd, 1H); 6.85(d, 1H); 6.6 
(dd, 2H); 5.95(d, 1H); 
4.35(q, 2H); 1.35(t, 3H). 
14 F F Cl H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.35(m, 3H); 6.95 
(d, 1H); 6.65(dd, 1H); 
5.9(d, 1H); 4.35(q, 2H); 
1.35(t, 3H). 
15 Cl 
Cl NO.sub.2 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 8.0(d, 1H); 7.75 
(s, 2H); 6.9(d, 1H); 6.65 
(dd, 1H); 6.0(d, 1H); 4.36 
(q, 2H); 1.37(t, 3H). 
16 Cl 
Cl Cl H F CO.sub.2 CH.sub.2 CH.sub.3 
O m.p. 110-112.degree. C. 
17 H Cl NO.sub.2 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 8.0(d, 1H); 7.85 
(s, 1H); 7.65(dd, 1H); 
7.25(s, 1H); 6.95(d, 1H); 
6.75(dd, 1H); 6.0(d, 1H); 
4.35(q, 2H); 1.35(t, 3H). 
18 F Cl Cl H F CO.sub.2 CH(CH.sub.3).sub.2 
O n.m.r. 7.6(s, 1H); 7.45 
(dd, 2H); 7.35(d, 1H); 6.9 
(d, 1H); 6.6(dd, 1H); 5.85 
(d, 1H); 5.18(m, 1H); 
1.35(t, 6H). 
19 F Cl Cl H F CO.sub.2 CH.sub.2 CH(CH.sub.3).sub.2 
O n.m.r. 7.6(s, 1H); 7.45 
(dd, 1H); 7.35(s, 1H); 
6.9(d, 1H); 6.6(dd, 1H); 
5.9(d, 1H); 4.1(m, 2H); 
2.0(m, 1H); 0.95(d, 6H). 
20 F Cl Cl H F 
##STR5## O n.m.r. 7.58(s, 1H); 7.35 (m, 7H); 
6.88(d, 1H); 6.6 (dd, 1H); 5.95(d, 
1H); 5.3 (d, 2H). 
21 F Cl Cl H F CO.sub.2 (CH.sub.2).sub.5 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(dd, 1H); 7.35(d, 1H); 
6.9(d, 1H); 6.58(dd, 1H); 
5.85(d, 1H); 4.3(t, 2H); 
1.7(m, 2H); 1.35 
(m, 6H); 0.9(t, 3H). 
22 F Cl Cl H F CO.sub.2 C(CH.sub.3).sub.3 
O n.m.r. 7.6(s, 1H); 7.42 
(dd, 1H); 7.35(d, 1H); 
6.9(d, 1H); 6.6(dd, 1H); 
5.8(d, 1H); 1.55(s, 9H). 
23 F Cl CN H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.65(s, 1H); 7.6 
(d, 1H); 7.45(dd, 1H); 
6.9(d, 1H); 6.65(dd, 1H); 
6.0(d, 1H); 4.4(q, 2H); 
1.35(t, 3H). 
24 F Cl Cl H F CO.sub.2 CH.sub.2 CCH 
O n.m.r. 7.6(s, 1H); 7.45 
(dd, 1H); 7.35(d, 1H); 
6.9(s, 1H); 6.6(dd, 1H); 
5.95(d, 1H); 4,88(d, 2H); 
2.57(s, 1H). 
25 F Cl CH.sub.3 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(d, 1H); 7.1(d, 1H); 6.8 
(d, 1H); 6.5(dd, 1H); 5.85 
(d, 1H); 4.35(q, 2H); 2.25 
(s, 3H); 1.35(t, 3H). 
26 F Cl CO.sub.2 CH.sub.3 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.9(d, 1H): 7.6 
(d, 1H); 7.45(q, 1H); 
6.85(d, 2H); 6.7(q, 1H); 
5.95(d, 2H); 4.4(q, 2H); 
3.9(s, 3H); 1.4(t, 3H). 
27 F Cl CHO H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.9(d, 1H); 7.6 
(d, 1H); 7.45(q, 1H); 6.9 
(d, 1H); 6.65(q, 1H); 6.05 
(d, 1H); 4.4(q, 2H); 1.4 
(t, 3H). 
28 F Cl .sub.n C.sub.3 H.sub.7 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(d, 1H); 7.4 
(q, 1H); 7.1(d, 1H); 6.8 
(d, 1H); 6.5(q, 1H); 5.9 
(d, 1H); 4.4(m, 2H); 2.6 
(m, 3H); 1.6(m, 2H); 
1.35(t, 3H); 0.9(t, 3H). 
29 F Cl 
##STR6## 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.5(d, 1H); 7.3 (q, 1H); 
7.05(d, 1H); 6.7 (d, 1H); 6.45(q, 
1H); 5.8(d, 1H); 4.3(m, 2H); 2.8(m, 
1H); 1.7(m, 5H); 1.25(m, 8H). 
30 F Cl COCH.sub.3 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.85(d, 1H); 7.6 
(d, 1H); 7.45(q, 1H); 6.9 
(d, 1H); 6.6(q, 1H); 6.05 
(d, 1H); 4.4(q, 2H); 2.65 
(s, 3H); 1.4(t, 3H). 
31 F Cl Cl H Br 
CO.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.45 
(d, 1H); 7.35(d, 1H); 
6.19(s, 1H); 6.65(d, 1H); 
6.45(s, 1H); 3.9(s, 3H). 
32 F Cl Cl H Br 
CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(d, 1H); 7.35(d, 1H); 6.9 
(s, 1H); 6.65(d, 1H); 6.4 
(s, 1H); 4.4(q, 2H); 1.4 
(t, 3H). 
33 F Cl Cl H Cl 
CO.sub. 2 CH.sub.3 
O n.m.r. 7.6(s, 1H); 7.4 
(d, 1H): 7.35(d, 1H); 6.9 
(s, 1H); 6.65(d, 1H); 6.22 
(s, 1H); 3.95(s, 3H). 
34 F Cl C.sub.2 H.sub.5 
H F CO.sub.2 CH.sub.2 CH.sub.3 
O n.m.r. 7.6(d, 1H); 7.4 
(q, 1H); 7.1(d, 1H); 6.8 
(d, 1H); 6.5(q, 1H); 
5.9(d, 1H); 4.35(m, 2H); 
2.65(q, 2H); 1.35(t, 3H); 
1.2(t, 3H). 
35 F Cl Cl H F CONHSO.sub.2 CH.sub.3 
O 
__________________________________________________________________________ 
A further particular example is Compound No. 36 
##STR7## 
characterising data: 
n.m.r. 8.25 (s, 1H); 8.0 (d, 1H); 7.5 (d, 1H); 7.1 (d, 1H); 7.0 (dd, 1H); 
5.8-6.05 (d, 1H); 4.4 (g, 2H); 1.4 (t, 3H). 
Compounds of formula (I) can be prepared by reaction of a compound of 
formula (II) 
##STR8## 
wherein X, R.sup.1, R.sup.2 and R.sup.4 are as defined in relation to 
formula (I); with a compound of formula (III) 
EQU Y--CR.sup.5 R.sup.6 R.sup.7 (III) 
wherein R.sup.5, R.sup.6 and R.sup.7 are defined in relation to formula (I) 
and Y is a leaving group. 
Suitably the reaction is carried out in the presence of a base such as 
sodium hydroxide or potassium carbonate. 
Examples of leaving groups for Y include halo such as chloro, bromo or 
iodo, mesylate or tosylate groups. 
The reaction is suitably carried out in an inert organic solvent such as 
dimethylsulphoxide at a temperature for example of from 
40.degree.-120.degree. C. Thereafter if desired one or more of the 
following steps may be carried out: 
i) when R.sup.7 is alkoxycarbonyl hydrolysinq to the corresponding acid; 
and 
ii) when R.sup.7 is COOH esterifying or forming a salt, amide, 
sulphonamide, hydrazide or hydrazinium derivative. 
Compounds of formula (II) may have herbicidal activity in their own right 
and the use of these compounds as herbicides forms another aspect of the 
invention. In addition some of the compounds of formula (II) are novel and 
this forms yet another aspect of the invention. Examples of compounds of 
formula (II) are shown in Table II. 
TABLE II 
__________________________________________________________________________ 
##STR9## 
COMPOUND 
NO. R.sup.1 
R.sup.2 
R.sup.4 
X CHARACTERISING DATA 
__________________________________________________________________________ 
37 F CF Cl O n.m.r. 
7.33(d, 2H); 7.27(d, 1H); 6.61 
(s, 1H); 6.49(d, 1H); 5.58(s, 1H). 
38 F CCl Br O n.m.r. 
7.59(s, 1H); 7.4(d, 2H); 6,55 
(s, 1H); 6.45(d, 1H); 5.59(s, 1H). 
39 F CCl NO.sub.2 
O n.m.r. 
8.15(d, 1H); 7.6(s, 1H); 7.45(d, 
6.65(d, 1H); 6.45(d, 1H). 
40 F CCl Cl O n.m.r. 
7.59(s, 1H); 7.4(dd, 1H); 7.25 
(d, 1H); 6.55(d, 1H); 6.46(dd, 1H) 
5.62(s, 1H). 
41 Cl 
CCl Cl O n.m.r. 
7.68(s, 1H); 7.26(d, 1H); 6.49 
(s, 1H); 6.42(d, 1H); 5.63(s, 1H). 
42 F CCl H O n.m.r. 
7.5(s, 1H); 7.3(d, 1H); 7.1(t, 1H 
6.5(d, 1H); 6.35(d, 1H); 6.25(d, 
4.75(s, 1H). 
43 H CNO.sub.2 
Cl O n.m.r. 
8.25(s, 1H); 7.75(d, 1H); 7.35 
(d, 1H); 7.15(d, 1H); 6.75(s, 1H); 
6.6(dd, 1H); 5.95(broad s, 1H). 
44 Cl 
CCl NO.sub.2 
O n.m.r. 
8.1(d, 1H); 7.75(s, 1H); 6.5 
(d, 1H); 6.35(s, 1H). 
45 Cl 
CCl H O n.m.r. 
7.7(s, 1H); 7.15(t, 1H); 6.55(d, 1H) 
6.45(d, 1H); 6.35(s, 1H); 4.85 
(s, 1H). 
46 F CCl CN O n.m.r. 
7.6(s, 1H); 7.45(d, 1H); 7.42(d, 1H) 
6.55(d, 1H); 6.5(s, 1H). 
47 F CCl CH.sub.3 
O n.m.r. 
7.55(s, 1H); 7.4(d, 1H); 7.0(d, 1H) 
6.4(s, 1H); 6.35(d, 1H); 4.85 
(s, 1H); 2.2(s, 3H). 
48 F CCl CH.sub.2 CH.sub.3 
O n.m.r. 
7.55(d, 1H); 7.4(q, 1H); 7.0(d, 1H); 
6.4(q, 1H & d, 1H); 5.1(s, 1H); 2.6 
(q, 2H); 1.2(t, 3H). 
49 F CCl CO.sub.2 CH.sub.3 
O n.m.r. 
11.0(s, 1H); 7.85(d, 2H); 7.6(d, 1H); 
7.4(dd, 1H); 6.5(dd, 1H); 6.35 
(d, 1H); 3.95(s, 3H). 
50 F CCl CHO O n.m.r. 
11.4(s, 1H); 9.8(s, 1H); 7.6(d, 1H); 
7.55(d, 1H); 7.45(q, 1H); 6.6(q, 1H); 
6.3(s, 1H). 
51 F CCl nPr O n.m.r. 
7.55(d, 1H); 7.35(q, 1H); 7.0(d, 1H); 
6.4(q, 1H & d, 1H); 5.05(s, 1H); 2.5 
(t, 2H); 1.6(m, 2H); 0.95(t, 3H). 
52 F CCl 
##STR10## 
O n.m.r. 
7.55(d, 1H); 7.35(q, 1H); 7.05(d, 1H) 6.4(d, 
1H); 6.35(q, 1H); 5.8(s, 1H); 2.57(m, 1H); 
1.85(d, 4H); 1.75 (d, 2H); 1.4(m, 4H). 
53 F CCl COCH.sub.3 
O n.m.r. 
12.6(s, 1H); 7.75(d, 1H); 7.6(d, 1H) 
7.45(q, 1H); 6.55(q, 1H); 6.3(d, 1H); 
2.6(s, 3H). 
54 Cl 
N Cl O n.m.r. 
8.3(s, 1H); 8.0(s, 1H); 7.4(d, 1H); 
6.9(d, 1H); 6.7(dd, 1H); 5.75 
(s, 1H). 
55 F CCl C.sub.2 F.sub.5 
O n.m.r. 
10.5(broad 1H); 8.13(d, 1H); 7.5 
(d, 1H); 6.77(s, 1H); 6.45(d, 
__________________________________________________________________________ 
1H). 
Compounds of formula (II) can be prepared by reacting a compound of formula 
(IV) 
##STR11## 
wherein R.sup.1 and R.sup.2 are as defined in relation to formula (I) and 
R.sup.16 is halo preferably fluoro or chloro with a compound of formula 
(V) 
##STR12## 
where X and R.sup.4 are as defined in relation to formula (I) and R.sup.17 
is H or a blocking group, preferably alkyl; and thereafter if necessary 
removing any blocking groups R.sup.17. 
The reaction is preferably carried out in the presence of a base. Suitable 
bases include potassium carbonate. 
The reaction is preferably carried out in an inert organic solvent such as 
dimethysulphoxide at temperatures for example of from 
20.degree.-120.degree. C. optionally. in an inert atmosphere. 
Alternatively compounds of formula (I) can be prepared directly by reacting 
a compound of formula (IV) with a compound of formula (VI) 
##STR13## 
wherein X,R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are as defined in relation 
to formula (I). The reaction conditions employed will be similar to these 
described above for the reaction of compound of formula (IV) with a 
compound of formula (V). Compounds of formula (I) or (II) where R.sup.4 is 
nitro or halo can be prepared by nitration or halogenation respectively of 
a compound of formula (VII) 
##STR14## 
wherein R.sup.1, R.sup.2 and X are as defined in relation to formula (I) 
and R.sup.18 is hydrogen or a blocking group such as alkyl, or CR.sup.5 
R.sup.6 R.sup.7 where R.sup.5, R.sup.6 and R.sup.7 are as defined in 
relation to formula (I); and thereafter if necessary removing any blocking 
groups R.sup.18 The nitration reaction may be carried out under 
conventional conditions, for example by reaction with a nitrating agent 
such as nitric acid in sulphuric acid or copper nitrate and acetic 
anhydride in acetic acid. 
Similarly halogenation may be effected by reation with a halogenating agent 
such as chlorine or bromine in for example acetic acid. Compounds of 
formula (VII) can be prepared by reacting a compound of formula (IV) with 
a compound of formula (VIII) 
##STR15## 
where X is as defined in relation to formula (I) and R.sup.18 is as 
defined in relation to formula (VII). The reaction conditions will be 
similar to those described above for the reaction between a compound of 
formula (IV) and a compound of formula (V). Removal of blocking groups 
R.sup.17 and R.sup.18 can be effected by reaction with an acid such as 
hydrobromic acid in acetic acid or with pyridine hydrochloride or boron 
tribromide. 
Compounds of formulae (IV), (V) (VI) and (VIII) are known compounds or can 
be made from known compounds by conventional methods. 
Compounds of formula (II) wherein R.sup.4 is haloalkyl can be prepared by 
reacting a compound of formula (II) wherein R.sup.4 is bromo or iodo with 
an appropriate haloalkyl iodide at elevated temperatures in the presence 
of copper powder as described for example by Kobayashi et al 
(Chem.Pharm.Bull (Japan) 1970, 18, 2334-2339) and by the method described 
by Carr et al ( J.Chem.Soc. Perkin Trans. I. 1988 p 921-926). 
Compounds of formula (I) where R.sup.7 is a COOH group may be produced by 
hydrolysis of an appropriate ester; derivatives of the acid e.q. esters, 
amides, aldehydes may be produced by conventional procedures. 
Compounds of formula (I) where R.sup.5 or R.sup.6 is chlorine or bromine 
and R.sup.7 is CO.sub.2 R.sup.8 may be produced by halogenation of the 
corresponding compound where R.sup.5 and R.sup.6 =H. Suitable reagents 
include NBS or chlorine gas in the presence of light or radical 
inhibitors. The halo ester obtained can be converted to other acid 
derivatives by standard means. 
The compounds of the invention are capable of controlling the growth of a 
wide variety of plants and in particular some show a useful selectivity in 
crops such as rice, cereals, maize, soya and sugar beet while others show 
broad spectrum activity. They may be applied to the soil before the 
emergence of plants (pre-emergence application) or they may be applied to 
the above ground parts of growing plants (postemergence application). In 
general the compounds are more active by post emergence application. In 
another aspect, therefore, the invention provides a process of inhibiting 
the growth of unwanted plants, by applying to the plants, or to the locus 
thereof, a compound of the formula (I) as hereinbefore defined. The rate 
of application required to inhibit the growth of unwanted plants will 
depend on, for example, the particular compound of formula (I) chosen for 
use, and the particular species of plant it is desired to control. 
However, as a general guide, an amount of from 0.01 to 5.0 kilograms per 
hectare, and preferably 0.025 to 2 kilograms per hectare is usually 
suitable. 
The compounds of the invention are preferably applied in the form of a 
composition, in which the active ingredient is mixed with a carrier 
comprising a solid or liquid diluent In another aspect, therefore, the 
invention provides a herbicidal composition, comprising as an active 
ingredient a compound of the formula (I) as hereinbefore defined, in 
admixture with a solid or liquid diluent. Preferably the composition also 
comprises a surface active agent. 
The solid compositions of the invention may be for example, in the form of 
dusting powders, or may take the form of granules. Suitable solid diluents 
include, for example, kaolin, bentonite, kieselquhr, dolomite, calcium 
carbonate, talc, powdered magnesia, and Fuller's earth. Solid compositions 
also include soluble powders and granules which may comprise a compound of 
the invention in admixture with a watersoluble carrier. 
Solid compositions may also be in the form of dispersible powders or grains 
comprising in addition to the active ingredient, a wetting agent to 
facilitate the dispersion of the powder or grains in liquids. Such powders 
or grains may include fillers, suspending agents and the like. 
Liquid compositions include solutions, dispersions and emulsions containing 
the active ingredient preferably in the presence of one or more surface 
active agents. Water or organic liquids may be used to prepare solutions, 
dispersions, or emulsions of the active ingredient. The liquid 
compositions of the invention may also contain one or more corrosion 
inhibitors for example lauryl isoquinolinium bromide. 
Surface active agents may be of the cationic, anionic or non-ionic type. 
Suitable agents of the cationic type include for example quaternary 
ammonium compounds, for example cetyltrimethylammonium bromide. Suitable 
agents of the anionic type include for example soaps, salts of aliphatic 
mono-esters of sulphuric acid, for example sodium lauryl sulphate; and 
salts of sulphonated aromatic compounds, for example 
dodecylbenzenesulphonate, sodium, calcium and ammonium lignosulphonate, 
butylnaphthalene sulphonate, and a mixture of the sodium salts of 
diisopropyl- and triisopropyl-naphthalenesulphonic acid. Suitable agents 
of the non-ionic type include, for example, the condensation products of 
ethylene oxide with fatty alcohols such as oleyl alcohol and cetyl 
alcohol, or with alkyl phenols such as octylphenol, nonylphenol, and 
octylcresol. Other nonionic agents are the partial esters derived from 
long chain fatty acids and hexitol anhydrides, for example sorbitol 
monolaurate; the condensation products of the said partial esters with 
ethylene oxide and the lecithins; and silicone surface active agents 
(water soluble surface active agents having a skelton which comprises a 
siloxane chain e.q. Silwet L77). A suitable mixture in mineral oil is 
Atplus 411F. 
The compositions which are to be used in the form of aqueous solutions, 
dispersions or emulsions are generally supplied in the form of a 
concentrate containing a high proportion of the active ingredient, the 
concentrate being diluted with water before use. These concentrates are 
usually required to withstand storage for prolonged periods and after such 
storage to be capable of dilution with water in order to form aqueous 
preparations which remain homogeneous for a sufficient time to enable them 
to be applied by conventional spray equipment. 
The compositions of the invention may contain, in addition to carriers and 
surface active agents, various other constituents to increase their 
usefulness. They may contain, for example, buffering salts to maintain the 
pH of the composition within a desired range; antifreeze agents, for 
example urea or propylene glycol; adjuvants, for example oils and 
humectants; and sequestrates, for example citric acid and 
ethylenediaminetetracetic acid, which help to prevent the formation of 
insoluble precipitates when the compositions are diluted with hard water. 
Aqueous dispersions may contain anti-settling agents and anti-caking 
agents. The compositions may in general contain a dye or pigment to impart 
a characteristic colour. Agents for increasing viscosity may be added to 
reduce the formation of fine droplets during spraying, and thereby reduce 
spray drift. Other additives useful for particular purposes will be known 
to those skilled in the formulation art. 
In general, concentrates may conveniently contain from 10 to 85% and 
preferably from 25 to 60% by weight of active ingredient. Dilute 
preparations ready for use may contain varying amounts of the active 
ingredient, depending upon the purpose for which they are to be used; 
however, dilute preparations suitable for many uses contain between 0.01% 
and 10% and preferably between 0.1% and 1% by weight of the active 
ingredient. 
The compounds of the invention can be used in association with another 
herbicide, for example in the form of a mixture or in a composition of the 
invention. 
The other herbicide will generally be a herbicide having a complementary 
action, depending upon the particular utility and circumstances of 
administration. 
Examples of useful complementary herbicides are: For example it may be 
desirable in certain circumstances to use the compound of formula (II) 
or(IIA) in admixture with a contact herbicide. 
Examples of useful complementary herbicides include: 
A. benzo-2,1,3-thiadiazin-4-one-2,2-dioxides such as 
3-isopropylbenzo-2,1,3-thiadiazin-4-one-2, 2-dioxide (bentazon); 
B. hormone herbicides, particularly the phenoxy alkanoic acids such as 
4-chloro-2-methylphenoxy acetic acid (MCPA), S-ethyl 4-chloro-O-tolyloxy 
thio-acetate (MCPA-thioethyl), 2-(2,4-dichlorophenoxy) propionic acid 
(dichlorprop), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 
4-(4-chloro-2-methylphenoxy)butyric acid (MCPB), 2,4-dichlorophenoxyacetic 
acid (2,4-D), 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB), 
2-(4-chloro-2-methylphenoxy) propionic acid (mecoprop), 
3,5,6-trichloro-2-pyridyloxyacetic acid (trichlopyr), 
4-amino-3,5-dichloro-6-fluoro- 2-pyridyloxyacetic acid (fluroxypyr), 
3,6-dichloropyridine-2-carboxylic acid (clopyralid), and their derivatives 
(eq. salts, esters and amides); 
C. 1,3 dimethylpyrazole derivatives such as 2-[4-(2,4-dichlorobenzoyl) 
1,3-dimethylpyrazol-5-yloxy]acetophenone (pyrazoxyfen), 
4-(2,4-dichlorobenzoyl)1,3-dimethylpyrazol-5-yltoluene suphonate 
(pyrazolate) and 
2-[4-(2,4-dichloro-m-toluolyl)-1,3-dimethylpyrazol-5-yloxy]-4'-methylaceto 
phenone (benzofenap); 
D. Dinitrophenols and their derivatives (e.g. acetates such as 
2-methyl-4,6-dinitrophenol (DNOC), 2-t-butyl-4,6-dinitrophenol (dinoterb), 
2-secbutyl-4,6-dinitrophenol (dinoseb) and its ester, dinoseb acetate; 
E. dinitroaniline herbicides such as 
N',N'-diethyl2,6-dinitro-4-trifluoromethyl-m-phenylenediamine 
(dinitramine), 2,6-dinitro-N,N-dipropyl4-trifluoro-methylaniline 
(trifluralin), 
N-ethyl-N-(2-methylallyl)-2,6-dinitro-4-trifluoromethylaniline 
(ethalflurolin), N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine 
(pendimethalin); and 3,5-dinitro-N.sup.4, N.sup.4 -dipropylsulphanilamide 
(oryzalin); 
F. arylurea herbicides such as N'-(3,4-dichlorophenyl)-N,N-dimethylurea 
(diuron), N,N-dimethyl-N'-[3-(trifluoromethyl) phenyl]urea (flumeturon), 
3-(3-chloro-4-methoxyphenyl)-1, 1-dimethylurea(metoxuron), 
1-butyl-3-(3,4-dichlorophenyl)-1-methylurea(neburon), 
3-(4-isopropylphenyl)- 1,1-dimethylurea (isoproturon), 
3-(3-chloro-p-tolyl)-1,1-dimethylurea (chlorotoluron), 3-[4-(4- 
chlorophenoxy) phenyl]-1, 1-dimethylurea (chloroxuron), 
3-(3,4-dichlorophenyl)-1-methylurea (linuron), 
3-(4-chlorophenyl)-1-methoxy-1-methylurea (monolinuron), 
3-(4-bromo-4-chlorophenyl)-1-methoxy-1-methylurea (chlorobromuron), 
1-(1-methyl-1-phenylethyl)-3-p-tolylurea(daimuron), and 
1-benzothiazol-2-yl-1,3-dimethylurea (methabenzthiazuron); 
G. phenylcarbamoyloxyphenylcarbamates such as 
3-[methoxycarbonylamino]phenyl (3-methylphenyl)-carbamate (phenmedipham) 
and 3-[ethoxycarbonylamino]-phenyl phenylcarbamate (desmedipham); 
H. 2-phenylpyridazin-3-ones such as 
5-amino-4-chloro-2-phenylpyridazin-3-one (pyrazon), and 
4-chloro-5-methylamino-2-.alpha.,.alpha.,.alpha.-trifluoro-m-tolyl) 
pyridazin-3(2H)-one (norflurazon); 
I. uracil herbicides such as 3-cyclohexyl-5,6-trimethyleneuracil (lenacil), 
5-bromo-3-secbutyl-6-methyl-uracil (bromacil) and 
3-t-butyl-5-chloro-6-methyl-uracil (terbacil); 
J. triazine herbicides such as 
2-chloro-4-ethylamino-6-(i-propylamino)-1,3,5-triazine (atrazine), 
2-chloro-4,6-di(ethylamino)-1,3,5-triazine (simazine), 
2-azido-4-(i-propylamino)6-methylthio-1,3,5-triazine (aziprotryne), 
2-(4-chloro-6-ethylamino-1,3,5-triazin-2-ylamino)-2-methylpropionitrile 
(cyanazine), N.sup.2, N.sup.4 
-di-isopropyl-6-methylthio-1,3,5-triazine-2,4-diamine (prometryne), 
N.sup.2 -(1,2-dimethylpropyl) -N.sup.4 
-ethyl-6-methylthio-1,3,5-triazine-2,4 -diamine (dimethametryne), 
N.sup.2,N.sup.4 -diethyl-6-methylthio-1,3,5-triazine-2,4-diamine 
(simetryne), and N.sup.2 -tert-butyl-N.sup.4 
-ethyl-6-methylthio-1,3,5-triazine-2,4-diamine (terbutryne); 
K. phosphorothioate herbicides such as S-2-methylpiperidinocarbonyl-methyl 
O,O-dipropyl phosphorodithioate (piperophos), S-2-benzenesulphonamidoethyl 
O,O-di isopropyl phosphonodithioate (bensulide), and O-ethyl 
O-6-nitro-m-tolyl sec-butylphosphoamidothioate (butamifos); 
L. thiolcarbamate herbicides such a S-ethyl 
N-cyclohexyl-N-ethyl(thiocarbamate) (cycloate), S-propyl 
dipropyl-thiocarbamate (vernolate), S-ethyl-azepine-1-carbothioate 
(molinate), S-4-chlorobenzyl diethylthiocarbamate (thiobencarb), S-ethyl 
di-isobutyl-thiocarbamate (butylate)*, S-ethyl diisopropylthiocarbamate 
(EPTC)*, S-2,3,3-trichloroallyl di-isopropyl (thiocarbamate) (tri-allate), 
S-2, 3-dichloroallyl di-isopropyl (thio-carbamate) (diallate), S-benzyl 
1,2-dimethylpropyl (ethyl) thiocarbamate (esprocarb), S-benzyl 
di(secbutyl)thiocarbamate (triocarbazil), 6-chloro-3-phenylpyridazin 4-yl 
S-octyl thiocarbamate (pyridate), and S-1-methyl-1phenylethylpiperidine 
-1-carbothioate (dimepiperate); 
M. 1,2,4-triazin-5-one herbicides such as 4-amino- 
4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazine-5-one(metamitron) and 
4-amino-6-t-butyl-4,5-dihydro-3-methylthio-1,3,4-triazin-5-one 
(metribuzin); 
N. benzoic acid herbicides such as 2,3,6-trichlorobenzoic acid (2,3,6-TBA), 
3,6-dichloro-2-methoxy-benzoic acid (dicamba) and 3-amino-2, 5-dichloro 
benzoic acid (chloramben); 
O. anilide herbicides such as 2-chloro-2',6' 
-diethyl-N-(2-propoxyethyl)acetanilide (pretilachlor), 
N-butoxymethyl-chloro-2', 6'-diethylacetanilide (butachlor), the 
corresponding N-methoxy compound (alachlor), the corresponding N-i-propyl 
compound (propachlor), 3',4'-dichloropropionilide (propanil), 
2-chloro-N-[pyrazol-1-ylmethyl]acet-2'-6' xylidide 
(metazachlor),2-chloro-6'-ethyl-N-(2-methoxy-1-methylethyl)acet-O-toluidid 
e (metolachlor), 2-chloro-N-ethoxymethyl-6'-ethylacet-O-toluidide 
(acetochlor), and 2-chloro-N-(2-methoxyethyl)acet-2',6'-xylidide 
(dimethachlor); 
P. dihalobenzonitrile herbicides such as 2,6-dichloro-benzonitrile 
(dichlobenil), 3,5-dibromo-4-hydroxy-benzonitrile (bromoxynil) and 
3,5-diiodo-4-hydroxy-benzonitrile (ioxynil); 
Q. haloalkanoic herbicides such as 2,2-dichloropropionic acid (dalapon), 
trichloroacetic acid (TCA) and salts thereof; 
R. diphenylether herbicides such as ethyl 2-[5-( 
2-chloro-trifluoro-p-tolyloxy)-2-nitrobenzoyloxy propionate (lactofen), 
D-[5-(2-chloro-, , -trifluoro-p-tolyloxy)-2-nitrobenzoyl] glycolic acid 
(fluroglycofen) or salts or ester thereof, 
2,4-dichlorophenyl-4-nitrophenyl ether (nitrofen), 
methyl-(2,4-dichlorophenoxy)-2-nitrobenzoate (bifenox), 
2-nitro-5-(2-chloro-4-trifluoromethyl-phenoxy) benzoic acid (acifluorfen) 
and salts and esters thereof, 2-chloro-4-trifluoromethylphenyl 3-ethoxy- 
4-nitrophenyl ether (oxyfluorfen) and 5-(2- 
chloro-4-(trifluoromethyl)phenoxy)-N-(methylsulfonyl)-2-nitrobenzamide 
(fomesafen); 2,4,6-trichlorophenyl 4-nitrophenyl ether (chlornitrofen) and 
5-(2,4-dichlorophenoxy)-2-nitroanisole (chlomethoxyfen); 
S. phenoxyphenoxypropionate herbicides such as 
(RS)-2-[4-(2,4-dichloro-phenoxy)phenoxy) propionic acid (diclofop) and 
esters thereof such as the methyl ester, 
2-(4-(5-trifluoromethyl)-2-(pyridinyl)oxy) phenoxypropanoic acid 
(fluazifop) and esters thereof, 
2-(4-(3-chloro-5-trifluoro-methyl)-2-pyridinyl)oxy)phenoxy)propanoic acid 
(haloxyfop) and esters thereof, 
2-(4-((6-chloro-2-quinoxalinyl)oxy)phenoxypropanoic acid (quizalofop) and 
esters thereof and 
(.+-.)-2-[4-(6-chlorooenzoxazol-2-yloxy)phenoxy]propionic acid 
(fenoxaprop) and esters thereof such as the ethyl ester; 
T. cyclohexanedione herbicides such as 2,2-dimethyl 
-4,6-dioxo-5-(1-((2-propenyloxy)imino)butyl) cyclohexane carboxylic acid 
(alloxydim) and salts thereof, 2-(1-ethoxyimino) 
butyl-5-(2-(ethylthio)-propyl)-3-hydroxy-2-cyclohexan-1-one(sethoxydim), 
2-(1-ethoxyimino) butyl)-3-hydroxy-5-thian-3-ylcyclohex-2-enone 
(cycloxydim), 2-[1-(ethoxyimino)propyl]-3-hydroxy 
-5-mesitylcyclohex-2-enone(tralkoxydim), and (.+-.) -2- 
(E)-1-[(E)-3-chloroallyloximino]propyl 
-5-[2-(ethylthio)propyl]-3-hydroxy-cyclohex-2-enone (clethodim); 
U. sulfonyl urea herbicides such as 2-chloro-N 
(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl) benzenesulphonamide 
(chlorosulfuron), methyl 
2-((((4,6-dimethyl-2-pyrimidinyl)amino)carbonyl)amino)sulphonylbenzoic 
acid (sulfometuron), 
2-(((3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbonyl) 
amino)-sulphonyl)benzoic acid (metsulfuron) and esters thereof; 
-(4,6-dimethoxypryrimidin-2-ylcarbamoylsuphamoyl)-O-toluic acid 
(benzsulfuron) and esters thereof such as the methyl 
3-[3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)ureidosulphonyl]thiophene-2-ca 
rboxylate (DPX-M6313), 2-(4-chloro-6-methoxy pyrimidin-2-yl 
carbamoylsulphamoyl benzoic acid (chlorimuron) and esters such as the 
ethyl ester thereof 2-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulphamoyl)-N, 
N-dimethylnicotinamide, 2-[4,6-bis(difluoromethoxy) 
pyrimidin-2-ylcarbamoylsulphamoyl) benzoic acid (pirimisulfuron) and 
esters such as the methyl ester thereof, 
2-[3-(4-methoxy-6-methyl-1,3,5-triazin-zyl)-3-methylureidosulphonyl) 
benzoic acid esters such as the methyl ester thereof (DPX-LS300) and 
5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulphamoyl)-1-methylpyrazole-4-carb 
oxylic acid (pyrazosulfuron); 
V. imidazolidinone herbicides such as 
2-(4,5-dihydro-4-isopropyl-4-methyl-5-oxoimidazol-2-yl) 
quinoline-3-carboxylic acid (imazaquin), methyl 
6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) -m-toluate and p-toluate 
isomer(imazamethabenz), 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) 
nicotinic acid (imazapyr) and isopropylammonium salts thereof, 
(RS)-5-ethyl-2-(4-isopropyl4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid 
(imazethapyr); 
W. arylanilide herbicides such as 
benzoyl-N-(3-chloro-4-fluorophenyl)-L-alanine (flamprop) and esters 
thereof, ethyl N-benzoyl-N-(3,4-dichlorophenyl)-DL-alaninate 
(benzoylpropethyl), 
N-(2,4-difluorophenyl)-2-(3-trifluoromethyl)phenoxy)-3-pyridinecarboxamide 
(diflufenican); and amino acid herbicides such as trimethylsulfonium 
N-(phosphonomethyl)-glycine (sulphosate), glyphosate and bialaphos; 
Y. organoarsenical herbicides such as monosodium methanearsonate (MSMA); 
Z. herbicidal amide derivative such as 
(RS)-N,N-diethyl-2-(1-naphthyloxypropionamide) (napropamide), 
3,5-dichloro-N-(1,1dimethylpropynyl)benzamide (propyzamide), 
(R)-1-(ethylcarbamoyl)ethyl carbanilate (carbetamide), N-benzyl-N- 
isopropylpivalamide (tebutam), (RS)-2-bromo- 
N-(.alpha.,.alpha.-dimethylbutyzamide (bromobutide), 
N-[3-(1-ethyl-1-methylpropyl)-isoxazol-5-yl]2,6-dimethoxybenzamide, 
(isoxaben), N-phenyl-2-(2-naphthyloxy) propionamide (naproanilide), N,N 
-dimethyl-diphenylacetamide (diphenamid), and N-(1-naphthyl)-phthalamic 
acid (naptalam); 
AA. miscellaneous herbicides including 2-ethoxy-2,3-dihydro-3, 
3-dimethylbenzofuran methanesulfonate (ethofumesate), 7-oxabicyclo 
(2.2.1)heptane,1-methyl-4-(1-methylethyl)-2-(2-methylphenylmethoxy)-exo 
(cinmethylin), 1,2-dimethyl-3,5-diphenylpyrazolium ion (difenzoquat) and 
salts thereof such as the methyl sulphate salt, 
2-(2-chlorobenzyl)-4,4-dimethyl-1,2-oxazoldin -3-one (clomazone), 
5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2(3H)-one 
(oxadiazon), 3,5-dibromo-4-hydroxy benzaldehyde 2,4-dinitrophenyloxime 
(bromofenoxim), 4-chlorobut-2-ynyl-3-chlorocarbanilate (barban), 
(RS)-2-(3,5-dichlorophenyl)-2-(2,2, 2-trichloroethyl)oxirane (tridiphane), 
(3RS,4RS; 
3RS,4SR)-3-chloro-4-chloromethyl-1-(.alpha.,.alpha.,.alpha.-trifluro-m-tol 
yl)-2-pyrrolidone (in the ratio 3:1) (fluorodichloridone), 
dichloroquinoline 8-carboxylic acid (quinchlorac) and 
2-(1,3-benzothiazol-2-yl- oxy)-N-methylacetanilide (mefanacet); 
BB. Examples of useful contact herbicides include: 
bipyridylium herbicides such as those in which the active entity is the 
1,1'-dimethyl-4,4'-bipyridylium ion (paraquat) and those in which the 
active entity is the 1,1'-ethylene-2,2'-bipyridylium ion (diquat); 
These compounds are preferably employed in combination with a safener such 
as 2,2-dichloro -N,N-di-2-propenylacetamide (dichlormid) 
The complementary herbicide is suitably present in the mixture or 
composition in an amount such that it is applied at its conventional rate. 
The following Examples illustrate the invention.