CA1251207A - Herbicidal 5-pyrimidylcyclohexan-1,3, dione derivatives - Google Patents

Abstract

ABSTRACT
Herbicidal 5-pyrimidylcyclohexan-1,3,dione derivatives The invention concerns novel compounds of the formula I

I

wherein:
X are selected from halogen, nitro, cyano, alkyl, substituted alkyl, hydroxy, alkoxy, substituted alkoxy, alkeny1, alkenyloxy, alynyl, alkynyloxy, acyloxy, alkoxycarbonyl, alkylthio, alkylsulfinyl, alkylsulfonyl, sulfamoyl, substituted sulfamoyl, alkanoyloxy, benzyl-oxy, substituted benzyloxy, amino, substituted amino, and the groups formyl and alkanoyl and the oxime, imine and Schiff base derivatives thereof;
R1 is selected from hydrogen, alkyl, alkenyl, alkynyl, substituted alkyl, alkylsulfonyl, arylsulfonyl, acyl and an inorganic or organic cation;
R2 is selected from alkyl, substituted alkyl, alkenyl, haloalkenyl, alkynyl and haloalkynyl;
R3 is selected from alkyl, fluoroalkyl, alkenyl, alkynyl, and phenyl;
R4 is selected from hydrogen, halogen, alkyl, cyano and alkoxycarbonyl and n is selected from the integers 1 and 2.
The compounds of the invention show herblcidal properties and plant growth regulating properties and in further embodiments the invention provides processes for the preparation of compounas of fonmula I, intermediates useful in the preparation of the compounds of fornula I, compositions containing as actiue ingred-ient a compound of formula I, and herbicidal and plant growtb regulating processes utilizing compounds of formula I.

Description

~2S~207 TITLE :
Herbicidal 5-pyrimidylcyclohexan-1,3,dione derivatives This invention relates to organic compounds hav-ing biological activity and in particular to organic compounds having herbicidal properties and plant growth regulating properties, to processes for the preparation of such compounds, to intenmediates useful in the pre-paration of such com2ounds and to herbicidal com-positions and processes utilizing such compounds and to plant growth regulating compositions and processes utilizing such compounds.
The use of certain ~yclohexane-1,3-dione deriva-tives as grass herbicides is ~nown in the art. For ex-ample, the ~Pesticide Manual~ (C R Worthing E~itor, The British Crop Prstection Council, 6th Edition 1979) des-cribes the cyclohexane-1,3-dione derivative ~DUWn commeroially as alloxydim-sodium (methyl 3-/I-[allyloxy-imino)bu~l7-4-hydroxy-6,6-dimethyl-2-oxocycloheY-3-ene carboxylate) and its use as a grass herbicide. lhis compound is disclosed in Australian Patent No 46~ 655 and its equivalents such as UK Patent No 1 ~61 170 and VS Patent No 3 950 420.
Mbre recently, at the 1980 British Crop ~,, ~25~2~7 Protection Conference (~1980 British Crop Protection Conference - Weeds, Pr~ceedings Vol 1, Research ~eports", pp 39 to 46, British Crop Protection Council, 1980), a new cyclohexane-1,3-dione grass herbicide code named NP 55 (2-~N-ethoxybutrimidoyl)-5-(2-ethylthiopropyl)-3-hydroxy-2-cyclohexen-1-one) was announced. This com-pound is disclosed in Australian Patent Application No A~-Al-35,314/78 and its ecuivalents.
It has now been found that a neh group of cyclo-hexane-1,3-dione derivatives which have a 5-pyrimidyl substituent exhibit particularly useful herbicidal activity.
Accordingly the invention pro~ides a compound of formula I:

/ ~-OR
(X) ~ C ~R3 Yherein:
X, ~hi~h may be the sa~e or different, aIe independently selected from the group consisting of: halogen; nitro;
c~ano; Cl to C6 alkyl; Cl to C6 al~ l substituted with a substituent selecte~ from the srou~ ccnsisting of halo-gen, nitro, hydroxy, Cl to C6 al~ and Cl to C6 alkyl-thio; C2 to C5 aIkenyl; C2 to C6 alk~-n~l; hydroxy; Cl to C6 aIkQxy; Cl to C6 al~oxy substit-ùted ~it.;. a substi-tu2nt selected from halogen and Cl to C6 aI~oxy; C2 to C al~e~yloxy; C2 to C6 al~nyloY~; C2 t 6 J~ZS1207 oxy; (Cl to C6 alkoxy)carbonyl; Cl to C6 alkylthio; Cl to C6 alkylsulfinyl; Cl to C6 alkylsulfonyl; sulfamoyl;
N-(Cl to C6 alkyl)sulfamoyl; N,N-di(Cl to C6 aIkyl)~
sulfamoyl; benzyloxy; substituted benzyloxy wherein the benzene ring is substituted with from one to three sub-situents selected from the group consisting of hal~gen, nitro, Cl to C6 alkyl, Cl to C6 alkoxy and Cl to C6 haloalkyl; the group NRSR6 wherein R and R are in-dependently selected from the group consisting of hydrogen, Cl to C6 alkyl, C2 to C6 alkanoyl, benzoyl and benzyl; the groups forD~l and C2 to C6 alkanoyl and the oxime, imine and Schiff base derivatives thereof;
Rl is selected from the group consisting of: hydrogen;
Cl to C6 alkyl; C2 to C6 aLkenyl; C2 to C6 aIkynyl;
substituted Cl to C6 alkyl Yherein the alkyl group is substituted with a substituent selected from the group consisting of Cl to C6 alkoxy, Cl to C6 alkylthio, phenyl and substituted phenyl ~herein ~he benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, ' 1 C6 alkyl, Cl to C6 haloaIkyl, Cl to C
alkoxy and Cl to C6 aIkylthio; Cl to C6 (alkyl) sulfonyl;
benzenesulfonyl; substituted benzenesulfonyl wherein the benzene ri~g is substituted with rom one to three sub-stituents selected from the group consisting of hal~gen, ' Y o~ Cl to C6 aI~yl, Cl to Cs haloalkyl, Cl to C6 alkoxy and Cl to C6 aIkylthio; an acyl group; and an inorganic or organic cation;
R2 is selected from the group consisting of: Cl to C6 30 alkyl; C2 to C6 alkenyl; C2 to C6 halo~lkenyl; C2 to C6 alkynyl; C2 to C6 haloalkynyl; substituted Cl to C6 al~yl ~herein the alkyl grou~ is substituted ~ith a sub-stituent selected frGm the group consisting of halogen, Cl to C6 al~oxy, Cl to C6 al~ylthio, phenyl and sub-125~2()7 stituted phenyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, Cl to C6 alkyl, Cl to C6 haloalkyl, Cl to C6 alkoxy and Cl to C6 aIkylthio;
R3 is selected from the group consisting of: Cl to C6 alkyl; Cl to C6 fluoroalkyl; C2 to C6 alkenyl; C2 to C6 alkynyl; and phenyl;
R4 is selected from the group consisting of: hydrogen;
halogen; cyano; Cl to C6 aIkyl; and (Cl to C6 alkoxy)-carbonyl; and n is an integer selected from 1 and ~.
When in the compound of formula I X is chosen from the groups formyl and C2 to C6 aIkanoyl and the oxime, imine and Schiff base derivatives thereof, the nature of the oxime, inune and Schi~f base derivatives is not narrowly critical. Although not intending to be bound by theory, it is believed that in the plant the (substituted) imine group may be removed to give the corresponding compound of formula I in which X is ~oxn~l or C2 to C6 aIkanoyl. Suitable values for the groups formy~ and C2 to C6 aI~anoyl and the oxime, imîne and Schiff base derivatives thereof include groups of the formula -C(R7)=~R8 wherein R7 is chosen from hydrogen and Cl to C5 aIkyl, and R is chosen fr~m hyarosen, C
to C6 alkyl, phenyl, benzyl, hydroxy, Cl to C6 alkoxy, phenoxy and benzyloxy.
When in the compound of formula I Rl is chosen irom acyl the na~ure of the acyl group is not narro~-ly critical. Although not intending to be bound by theory, it is believed that when Rl is acyl the acyl group ~ay be removed in the plant by hydrolysis to give the corresponding campound of formula I in w~ich R is ~25~L207 hydrogen. Suitable acyl groups include: aIkanoyl, for example C2 to C6 alkanoyl; aroyl, for example benzoyl and substituted benzoyl wherein the ~enzene ring is substituted with from one to three substituents chosen from the group consisting of halogen, nitro, cyano, Cl to C6 alkyl, Cl to C6 haloalkyl, Cl to C6 al~oxy and Cl to C6 alkylthio; and heteroaroyl, for example

2-furoyl, 3-furoyl, 2-thenoyl and 3-thenoyl.
When in the compound of formula I R is chosen from an inorganic or organic cation the nature of tbe cation is not narrowly critical. Although not intend-ing to be bound by theory, it is believed that when is a cation the cation may be removed in the plant to give a compound of formula I wherein Rl is hydrogen.
Suitable inorganic cations include the aIkali and alkaline earth metal ions, heavy metal ions including the transition metal ions, and the ammonium ion. Suit-able organic cations include the cation R R R R N
wherein R , R , R and R are independently chosen from the group consisting of: hydrogen; Cl to C10 alkyl; substituted Cl to C10 alkyl wherein the alkyl group is substituted ~ith a substituent chosen from the group consisting of hydroxy~ halogen and Cl to C6 alkoxy; phenyl; benzyl; and the groups substituted phenyl and substitutea benzyl wherein the benzene ring is substituted ~ith from one to three substituents chosen from the sroup consisting of halogen, nitro, cyano, Cl to C6 aI~yl, Cl to C6 haloalkyl, Cl to C6 alkoxy and Cl to C6 alkylthio.
3C The compouDds of the invention may exist in two isomeric forms as shswn, below wherein ~ represents the sroup ~L25~207 x) n~

C~ ~i ,~N_oR2 \ R ~ \ R

Ia Id It should be recognized that ffhen Rl is hydrogen, the compounds of the invention may exist in any one of four tautomeric forms as shown below.

~ ,9S~ -oR2 ~_oR2 R O R O
IIa IIb N-OR

IIc IId 12SlZ~7 Suitable X include Cl to C6 aLkyl, Cl to C6 alkoxy, Cl to C6 allcylthio, halogen, Cl to C6 haloaLlcyl, amino, Cl to C6 aLkylamino and di (Cl to C6 aLkyl) amino.
Suitable R include: hydrogen; Cl to C6 alkyl;
C2 to C6 al)cenyl; C2 to C6 allcynyl; substituted Cl to C6 alkyl wherein the alkyl group is substituted with a ~ub-stituent selected from the grou~ consisting of Cl to C6 allcoxy, Cl to C6 alkylthio, phenyl and substituted phenyl wherein the benzene ring is substituted with from one to three substituents selected from the group con-sisting of halogen, nitro, cyano, Cl to C6 alkyl, Cl to C6 haloalkyl, Cl to C6 alkoxy and Cl to C6 aLkylthio;
Cl to C6 laL~cyl)sulfom~l; benzenesulfonyl; substituted benzenesulfonyl wherein the benzene ring is substituted ~ith from one to three substituents selected from the group consisting of hal~gen, nitro, cyano, Cl to C6 alkyl, Cl to C6 haloalkyl, Cl to C6 alkoxy and Cl to C6 alkylthio; an acyl grou~; and an inorganic or organic cation .
Suitable R2 include: Cl to C6 alkyl; C2 to C6 allsenyl; C2 to C6 haloalken~l; C2 to C6 alkynyl; C2 to C6 haloalkynyl; substituted Cl to C6 aLlcyl wherein the aL~cyl group is substituted ~ith substituent selected frc~m the group consisting of halogen, Cl to C6 aLkoxy, 2; Cl to C6 al~cylthio, pheDyl and substituted phenyl ~erein the benzene ring is substituted with from one to three substituents selecte~ froID the group consisting of halogen, nitro, q,~ano, Cl to C6 alkyl, Cl to C6 haloal~cyl, Cl to C6 aLl~oxy and Cl to C6 alkylthio.
3C Suitable R3 include: Cl to C6 aLlcyl; Cl to C6 fluoroalkyl; C2 to C6 al3cenyl; C2 to C6 alkynyl; and p~eny 1 .
Suitable R4 include hydrogen.
Suitable n include the integers 1 and 2.
Preferred ca~?ounds of the invention inc:lude ~25~l20~

those compounds ~f formula I wherein:
X are independently selected from the group consisting of Cl to C6 alkyl, Cl to C6 alkoxy, Cl to C~ alkylthio, Cl to C6 alkylsulfinyl, Cl to C6 alkylsulfonyl, halogen, amino, N-(Cl to C6 alkyl)amino and N,N-di(Cl to C6 aIkyl)anuno;
Rl is selected from the group consisting of: hydrogen;
C2 to C6 alkanoyl; benzoyl and substituted benzoyl ~herein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, Cl to C6 alkyl and Cl to C6 alkoxy;
benzenesulfonyl and substituted benzenesulfonyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, Cl to C6 alkyl and Cl to C~ alkoxy; and an inorganic or an organic cation selected from ~he alkali m~tals such as lithium, potassium and sodium, the aIkaline earth metals such as magnesium, calcium and barium, the transition metals such as manganese, cop2er, zinc, iron, nickel, cobalt and silver, the a3D~iu~ ion and the tri- and tetra-(aIkyl)ammonium ions ~herein alkyl is selected from Cl to C6 alkyl and C to C6 hydroxyaIkyl;
R is selected from the group consisting of Cl to C6 25 aI~}l, C2 to C6 alkenyl, C2 to C6 alkynyl, Cl to C6 haloalkyl, C2 to C6 haloalkenyl and C2 to C6 halo-aL~ynyl;
R is selected from Cl to C6 al~yl;
R- is selected from hydrogen and halogen; and n is an integer selected fro~ 1 and 2.
~ore preferred cn~pounds of the invention in-12:51207 _ g _ clude th~se compounds of formula I in which the pyrimidine ring is linked ~hrough the 5-position to the cyclohexane ring. That is, compounds of formula IIIo ORl ,~ ~1i-OR2 III
(X)n ~4 wherein:
X are independently selected frQm the group consisting of Cl to C6 alkyl, Cl to C6 alkoxy, Cl to C6 al~ylthio, Cl to C6 alkylsulfinyl, Cl to C6 alkylsulfonyl, halogen, amino, N-(Cl to C6 alkyl)amino and N,N-di(Cl to C6 alkyl~a~ino;
Rl i5 selected from the group consisting of hydrogen, C2 to C6 aIkanoyl, benzoyl, the aLkali netals, the transition metals, the ammonium ion and the tri- and tetr~-(al~yl)ammonium ions w~erein alkyl is selected fro~ Cl to C6 aIkyl and Cl to C6 hyGroxyal~yl;
R2 is selected from the sroup consisting of Cl to C3 aI~yl, Cl to C3 haloaLkyl, allyl and haloallyl;
R is ~elected from Cl to C3 alkyl;
R is hydrogen; and n i5 an integer selected from 1 and 2.
Included among the ~ore preferred coEpo~nds of 1251~17 the invention are those 5-pyrimidyl compounds of formula III wherein:

X are independently selected from the group consisting of Cl to C6 alkyl, Cl to C6 alkoxy, Cl to C6 alkylthio and N,N-di(Cl to C6 aIkyl)amino;
Rl is selected frQm the group consisting of hydr~gen, C2 to C6 alkanoyl and the alkali metals;
R is selected from the group consisting of Cl to C3 al~yl, allyl and haloallyl;
10 R is selected from Cl to C3 alkyl;
R4 is hydrogen; and n is the integer 1.
Also included among the re preferred compounds of the invention are those S-pyrimi~yl compounds which are substituted in the 2-position of the pyrimidine ring. m at is, com~ounds of for~ula IIIa X ~ ~ \ R IIIa R O

wherein:
X is independ2ntly selecte~ fr the group consisting of Cl to C6 alkyl, Cl to C6 aIkoxy, Cl to C6 alkylthio, Cl to C6 alkylsulfinyl and N,N-di(Cl to C6 alkyl) amuno;
Rl is selected from the group consisting of hydrogen, C2 to C6 alkanoyl and the alkali metals;
R is selected from the ~roup consisting of Cl to C3 5 alkyl, allyl and haloallyl;
R3 is selected from Cl to C3 alkyl; and R4 is hydrogen.
Particularly preferxed values for X include methyl, methoxy, methylmercapto and N,N-dimethyla-~no.
Particularly preferred values for Rl include hydrogen, C2 to C6 alkanoyl, sodium and potassiur.
Particularly preferred values for R include ethyl, n-propyl, allyl and chloroallyl;
Particularly preferred values for R3 include ethyl and n-propyl.

Examples of compounas embraced by the invention include:

~ C2~5 1;~51207 ,OH

3 ~IC~ C2115 9e~a~

3 ~ ~ C21',5 0~
CH 30 ~ )CH2-C~=C~ 2 OB
3~( 3{~ C2~ 5 s ~C C2 5 12 o OCC(CE~3~ 3 ~{ ~ C2H5 13 ~25~21~7 CH3~ -C~99 14 Specific examples of the compounds of the in-vention include those compounds detailed in Tables la and lb.

~Z51.~7 ABLE la Rl 2 ~N~OR

~X~n O

Com- . _ . No ( X ) n R R

1 2-C~ 3 El C2~5 n-c3H 7 3 2-CH30 El C2~5 n-c3H 7

4 2-C~3S H C2~5 C2H5 2-CE13S Na ~ 2H5 C2H5 6 2-CE135 ~0) ~ C2~5 C2~5 7 2-C~13 El CH2CH=CEICl n~C3E1 7 8 2-CH30 COC~CH3~ 3 C2~5 n-C3~7 . _ 2--( CE~ 3) 2N ll C2~5 C~35 l;~Sl:~O~

TABLE lb ORl ~N-OR

lx)n o pound ¦( X I D ¦ R ¦ R ¦ R
. . _. _ .
. 10 5-CH 3 11 C2B5 .

~2~2~7 _ 16 --The compounds of th~ invention may be prepared by a variety of methods and in a :Eurther aspect the invention provides methods for the preparation of com-pounds of formula I.
Conveniently the preparation of the compounds of the invention can be considered in three or four parts.
Part A involves the formation of a 5-arylcyclo-hexan-1,3-dione of formula IX. m is reaction may be carried out in a two step process b~!:
(i) reacting, preferably in the presence of a base, an aldehyde derivative of formula V with acetone (IVa) or an acetone derivatiYe of for~.ula IVb to form a ketone d~rivative of for~ula VIa or VIb respectively; and reacting, preferably in the presence of a base, a ~etone derivative of formula VIa with a malonic acid ester derivative of formula VIIa or a ketone derivative of formula VIb with a ~alonic acid ester of formula VIIb, to give an interme~ia~e of formula VIIIa or VIIIb respectively Yhich may be isolated or hydrolysed directly, preferably in the presence of an acid, to ~ive a 5-arylcyclohexan-1,3-dione of formula IX, or reacting, preferably in the presence of a base, a ketone derivative of forcula Vla with an alkanoic acid ester of for~.ula ~IIc to give a 5-arylcyclohex~n-1,3-dione of form~}a IX;
(ii) reacting, preferably in the presence of a base, an alde~yde deri~ati~e of for~ula V with a 3G malonic acid ester o~ for~ula V~Ib to give an arylr~thylide~e~zlo-,ate deriYati~e of forr.ula VIc which is ir. turr. reacted, preferably i~ $he presence of ~ base, b-ith an acetoacetic acid ester deri~ative of for~-;la ~ to si~e an intermediate of fsrmula VIIIc which may be isolated or hydrolysed directly, preferably in the presence of an acid, to give a 5-arylcyclohexan-1,3-dione of formula IX; or (iii) reacting, preferably in ~he prese~ce of a base, an aldehyde derivative of formula Y with an acetic acid ester of formula IVc to give a 2-arylalkenoate derivative of formula Vld which is in turn reacted, preferably in the presence of a base, with an acetoacetic acid ester derivativ~e of formula VII d to give an inter~ediate of formula VIIIa which may be isolated or hydrolysed directly, preferably in the presence of an acid, to gi~re a 5-arvlcyclohexan-1,3-dione of formula IX.
Part ~ involves the acylation of a compound of formula IX to give a 2-acyl-5-arylcyclohexan-1,3-dione of foxmula XIII. This reaction may be carried out by reacting a 5-arylcyclohexan-1,3-dione of formula IX
with:
(iv) an acid anhydride of formula X in the presence of either an aIkali metal salt of the corresponding acid of formula XI or an aIkoxide salt of formula XII, ~herein ~ is an alkali ~etal ion and R is 2~ Cl to C6 alkyl;
(v) an acid anh~dride of formula X in the presence of the corresponding acid of for~ula ~IV;
~vi) an acid ha~ide of formula x~r, ~herein hal re-presents halog~e~ the presence of a Lewis acid catalyst;
~vii) a ~ixture of an aci~ halide of formula ~V and the ~25120~

correspondins acid o, formula XIV; or (viii) with an aLkali or alkaline earth metal hydride followed by reaction with an acid anhydridle of formula X or an acid halide of formula XV.
Alternatively, this acylation reaction may be carried out by:
(ix) reacting a 5-arylcyclohexan-1,3-dione of formula IX with an acid halide of formula XV in the presence of pyridine to give an intermediate O-acyl derivative of formula XVI; and (x) reacting the intermediate of formula XVI with a Lewis acid catalyst;
(xi) reacting the intermediate of formula XVI with the acid of formula XIY; or

5 ~xii) reac~ing the intermediate of formula XVI ~ith imidazole.
Part C involves the for~ation of a compound of the invention of formula I ~herein Rl is hydrogen, that is a compound of formula II. This reaction may be carried out either by reacting a 2-acyl-5~arylcyclo-hexan-1,3-dione of formula XIII with:
(xiii) an alkoxya~ine derivative of formula XVII; or ~xiv) hydroxylA~ine to give an intermediate oxime derivative of formula XVIII a~d reacting that intermediate oxime derivative of formula XVIII
~ith an aLkylating agent of formula XIX ~herein L ~s a leaving group such as, for example, chloride, bromide, iodide, sulfate, ~itrate, methyl sulfate, ethyl sulfate, tetrafluoroborate, ~-~ 1 25 12~7 hexafluorophosphate, hexafluoroantimonate, methanesulfonate, flu~rosulfonate, fluoro-methanesulfonate and trifluoromethanesulfonate.
Part D involves the formation of a compound of the invention of formula I ~herein Rl is a substituent other than hydrogen.
Co~pounds of the invention of formula I, wherein Rl forms an ether, acyl or sulfonyl derivative of a compound of formula II, may be prepared from ~he corres-ponding compounds of the invention of formula II by re-acting with an etherification, acylation or sulfonyla-tion reagent of formula XX.
Compounds of the invention of formula I wherein Rl is an inorganic or organic cation may be prepared fr the compounds of the invention of formula I
wherein Rl is hydrogen, that is, compounds of formula II, by reacting said compounds of formula II with an inorganic or organic salt. For example, tbe compounds of formula I wherein Rl is an aIkali metal ion may be prepared by reacting the appropriate co~pound of formula II with the appropriate alkali metal hydroxide or alko~ylate. The compounds of formula I wherein R
is a transition metal ion or an organic cation ~ay si~ilarly be prepared by reacting the appropriate com-pound of formula II with an appropriate transitionmetal salt or organic base. Alternatively the com-pounds of formula I wherein Rl is a transition ~etal ion or an organic cation may be prepared by reacting the appropriate compound of formula I wherein Rl is an 3~ aI}ali ~etal ion with an a~prcpriate transition ~etal salt or organic salt.
Accordingly, in a further aspect the invention provides a process for the preparation of a co~p~und of formula I, as hereinbefore defined, which procYss com-prises:

~251207 reacting 2-acyl-5-~aryl)cyclohexane-1,3-dione derivative of formula XIII with an alkoxyamine derivative of formula XVII to give a cRmpound of the invention of formula II or reacting the 2-acyl-5-(aryl)cyclohexane-1,3-dione derivative of formula XIII with hydroxylamine and aIkylating the oxime intermediate of for~.ula XVIII with an alkylating agent of formula XIX, wherein L is a leaving group, to give a compound of the in-vention of formula II; and ~ptionally reacting the compound of the invention of formula II with a compound of formula XX, wherein L is a leaving group, to give a compound of the inven-tion of formula I.
me structures of the compounds described above are detailed on the following pages wherei~ 0 represents the ~roup (X~n 1;2 51207 oRl ~H
~3 ~ //N-OR

II

CB 3COCH 3 C~ 3COCH 2 R CH 3C02R

IYa IVb IVc V

5~-C~--CH-COCH30-C~=CR --COCE33 Vla VIb S~CH=C ( CO2R) 2~)--CB=C~}--CO2R

Vlc VId P~ C~; ~C02R) 2CH2 ~C02R? 2 VI I a VI Ib ~25~2V7 R C~ 2 C02R C~ 3CO(~H R Ct:~2R
VIIC VIId 0~ 0~

co2~
VIIIa VIlIb RO_C o o "'2~ ~
VIIIc IX

(R CO) 2~ C02M ROM

X XI XII

pH
0 ~C~/
~ \R3 2~II

~S~Z07 -- 23 _ R CO2H R COhal XIV XY

ocoR3 0~

RO
XVI

H2NOR R2L RlL

XYII XIX XX

0~
~N--OH
0~ ~C
~ R3 R O

~VIII

12S~207 Certain of the intermediate oompounds of formulae V, YIa, VIb, VIc, VId, VIIIa, VIIIb, VIIIc, IX, XIII, XVI and XVIII are novel compounds and there-fore in further embodiments the invention provides novel compounds of formulae V, VIa, VIb, VIc, VId, VIIIa, VIIIb, VIIIc, IX, XIII, XVq ~nd XVIII and processes for the preparation thereof.
For example, none of the pyrimidine-carboxaldehydes of formula V used in the preparation of the compounds of the invention of formula I has previously been described.
Accordingly, in a further aspect the invention provides a compound of formula V

N~`N
(X) nt~ C~O

wherein X and n are as hereinbefore defined.
A preferred group of coqpounds of the invention of formula I ~ay be prepared fro~ novel 2-substituted-pyrim;dine-S-carboxaldehydes. Accordingly in a fur~her aspect the invention provides pyrimidine-5-carboxaldehydes of formula Va ~3 va 125~20~

wherein X is as hereinbefore defined.
The compound 2,4,6- trimethoxypyrimidine-5-carboxaldehyde may be prepared by Yilsmeyer formylation of 2,4,6-trimethoxypyrimidine using N,N-dimethyl-formamide and phosphorus oxychloride. ffowever, Vilsmeyer formulation is only effective with aromatic compounds which are very reactive towards electrophilic aromatic substitution and the reaction works in this instance because of the presence of three strongly electron donating groups in the pyrimidine ring.
It is not possible to use the Vilsmeyer formylation reaction to prepare pyri~midine carbox-aldehydes in which the pyrimidine ring is not activated by stronyly electron donating groups. For example, it was necessary to find a new process to prepare the novel 2-substituted-pyrimidine-5-carboxaldehydes used in the preparation of a preferrea goup of compounds of the invention of formula I~ miS new process involves reacting a 2-(methylene)propanediylidene derivative, such as for example {2-~dimethylamino)methylene7-propanediylidene)bis~dimethylammonium perchlorate7, with an amidine derivative. Accordingly, in a further aspect the invention provides a process for the pre-paration of a pyrimidine-5-carboxaldehyde derivatiYe of formula Va N

X ~ ~ C~o Va ~hich pro oess comprises reactinq a 2-~methylene~-propanediylidene deriYati~e of formula XXI wherein R is selected fro~ Cl to C6 aI~yl ~ith an amidine deri~ati~e 1~5~2(~

of formula XXII wherein X i~ as hereinbefore defined, or a salt thereof.

~ CH=~(R)2 N~
(R)2NCH=C X-C-NH2 CH=~(R)2 XXI XXII

In a further embodiment the invention provides a compound of formula IX

N~N ~
(X)n ~ IX
r~

w~erein X, R4 and n are as hereinbefore defined.
In a still further embodiment the in~ention provides a com~ound of forDula XIII

0~

(X)n ~ C~ 3 XIII

~rein X, R3, R4 and n al~ as hereinbefore defined.

12S120~

The compounds of formula I are active as herbi-cides and ~herefore, in a further aspect the invention provides a process for severely damaging or killing un-wanted plants which process comprises applying to the plants, or to the growth medium of the plants, an effective amount of a cQmpound of formula I as herein-before defined.
Generally speaking the compounds of formula I
are herbicidally effective against a variety of plants.
However, certain of the compounds of the invention are selectively active against moncotyledonous plants, dicotyledonous plants being relatively unaffected by rates of application of the compounds of the invention which are severely damaging or lethal to other plant species.

Accordingly in a further aspect the invention provides a proc2ss for selectively controlling the growth of monocotyledonous weeds in dicotyledonous crops which process comprises applying to the crop, or to the growth medium of the crop, a compound of formula I in an amount sufficient to severely damage or kill said weeds but insufficient to substantially damage said crop.

m e compounds of formula I may be applied directly to the plant (post-emergence application) or to the soil before the emer~ence of the plant (pre-emergence application). ~owever, the compounds are, in general, more effective when applied to the plant pQS t-emergence.
The compounds of formula I may be used on their own to inhibit the growth of, severely damage, or kill plants but are preferably used in the form of a com-position comprising a cQm~ound of the invention in ad-mixture with a carrier comprising a solid or liquid diluent. Therefore, in yet a further aspect the in-venti~n provides growth inhibiting, plant damaging, or plant killing compositions comDrising a compound of formula I as hereinbefore defined and an a~ri-culturally acceptable carrier therefor.
Certain of the compounds of formula I exhibit useful plant growth regulating activity. For example, while cu~ounds of formula I are selectively active berbicides against wild grasses in crops of cultivated plants at s e rates of application they exhibit plant growth regulating effects in said crops.
Plant growth regulating effects m~y be nani-fested in a number of ways. For example, suppression of apical dom nance, stimulation of auxiliary bud growth ~2~12(~7 stimulation of early flowering and seed formation, en-haDcement of flowering and increase in seed yield, stem thickening, stem shortening and tillering. Plant growth regulating effects shown in compounds of the invention may include, for example, tillering and stem shortening in cropssuch as wheat and barley.
Accordingly in a still further aspect the in-vention provides a process for regulating the growth of a plant which process comprises applying to the plant, to the seed of the plant, or to the growth medium of the plant, an effective amount of a compound of formula I, as hereinbefore defined.
To effect the plant growth regulating process of the present invention the compounds of formula I may be applied directly to the plant (post-emergence applica-tion) or to the seed or soil before the emergence of the plant (pre-emergence) application.
me cQmpounds of formula I may be used on their own to regulate the growth of plants but in general are preferably use2 in the form of a composition comprising a compound of the invention in a~xture with a carrier comprising a solid or li~uid diluent. m erefore, in a still further aspect the invention provides plant growth regulating compositions comprising a compound of formula I as bereinbefore defined and an agriculturally acceptable carrier therefor.
The compositions of the present invention ~y be in the form of solids, liguids or pastes. The oom-p~sitions include both dilute o~mpositions which are ready for i~mediate use and ooncentrated compositions ~hich ~ay require dilution before use. merefore, the co~centration of the active ingredient in the com-positions of the present invention will vary depending on the types cf formulation and whether the coc2osition 35 is ready for use such as, for example, a dust formula- ;

~251ZO~

tion or an aqueous emulsion or whether the composition is a concentrate such as, for example, an emulsifiable concentrate or a wettable powder, which is suitable for dilution before use~ In general the compositions of the present invention comprise from 1 ppm to 99% by weight of active ingredient.
The solid cQmpositions may be in the form of powders, dusts, pellets, grains, and granules wherein the active ingredient is muxed with a solid diluent.
Powders and dusts may be prepared by mixing or grinding the active ingredient with a solid carrier to give a finely divided co~position. Granules, grains and pellets may be prepared by bonding the active ingredient to a solid carrier, for example, ~y coating or im-pregnating the preformed granular solid carrier with theactive ingredient or by agglomeration techniques.
Examples of solid carriers include: mineral earths and clays such as, for example, kaolin, bentonite, kieselguhr, Fuller's earth, Attaclay, diatomaceous earth, bole, loess, talc, chalk, dclQmite, limestone, lime, calcium carbo~ate, powdered magnesia, magnesium oxide, magnesium sulfate, gypsum, calcium sulfate, pyrophyllite, silicic acid, silicates and silica gels; fertilizers such as, for example, ammonium sulfate, ammonium phosphate, a~moniu~ nitrate and urea; natural products of vegetable ori~in such as, for example, grain meals and flours, bar~ meals, ~od ~eals, nutshell meals and cellulQsic pc~ers; and synthetic polymeric materials such as, for exam2le, ground or powdered plastics and resins.
Alternatively, the solid compositions may be in the for~ of dispe-sible or ~ettable du~ts, powders, granules or grains ~erein the active ingredient and the solid carrier are co~bined with one or hore surface active agents ~hic~ act as wettiDg, emulsifying and/or ~25120 dispersing agents to facilitate the dispersion of the active ingredient in liquid.
Examples of surface active agents include those of the cationic, anionic and non-ionic type. Cationic surface active agents include quaternary ammonium com-pounds, for example, the long chain alkylammonium salts such as cetyltrimethyla~monium bromide. Anionic surface active agents include: so~ps or the alkali metal, aIkaline earth metal and ammonium salts of fatty acids;
the alkali metal, aIkaline earth metal and ammonium salts of ligninsulfonic acid; the aIkali metal, alkaline earth metal and am~onium salts of arylsulfonic acids including the salts of naphthalenesulfonic acids such as butylnaphthalenesulfonic acid, the di- and tri-isopropylnaphthalenesulfonic acids, the salts of thecondensation products of sulfonated naphthalene and ~aphthalene derivatives with formaldehyde, the salts of the condensation products of sulfonated naphthalene and naph~halene derivatives ~ith phenol and formaldehyde, and the salts of al~ylarylbenzenesulfonic acids such as do~ecylbenzenesulfonic acid; the alkali metal, aIkaline earth metal and a~oni D salts of the long chain no esters of sulfuric acid or aIkylsulfates such as laurylsulfate and the m~no esters of sulfuric acid ~ith fatty alcohol glycol ethers. Nonionic sur-face active agents include: the condensation products of et~ylene oxide ~ith fatty alcohols such as oleyl aloohol and cetyl alcohol; the condensation products of ethylene oxide with phenols and alkylphenols such as isoDc~ylphenol, octylphenol and nonylphenol; ~he con-densation products o~ ethylene oxide with castor oil;
the partial esters deriYed from long chain fatty acids and hexitol anhydrides, for example sorbitan mono-laurate, and their co~densation products ~ith ethylene o~ide; ethylene oxide~pr~pylene oxide block copolymers;

~25~207 lauryl alcohol polyglycol ether acetal; and the lecithins~
The liquid com?ositions may comprise a solution or dispersion of the active ingredient in a liquid carrier optionally containing one or more surface active agents which act as wetting, emulsifying and~or dis-persing agents. Examples of liquid carriers include:
water; mineral oil fractions such as, for example, kerosene, solvent naptha, Detroleum, coal tar oils and aro~atic petroleum fractions; aliphatic, cycloaliphatic and aromatic hydrocarbons such as, for example, paraffin, cyclohexane, toluene, the xylenes, tetra-hydronaphthalene and alkylated naphthalenes; alcohols such as, for example, ~ethanol, ethanol, propanol, isopropanol, butanol, cyclohexanol and propylene glycol;
~etones such as, for example, cyclohexanone and isophorone; and strongly polar organic solvents such as, for example, dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone and sulfolane.
2n A preferred liquid composition comprises an aque~us suspension, dispersion or emulsion of the active ingre~ient which is suitable for application by spraying, atomizing or watering. Such aaueous co~positions are generally prepared by mixing concentrated c positions ~ith ~ater. Suitable con oe ntrated compositions include enulsion concentrates, pastes, oil dispersions, aqueous suspensions and wettable ?owders. The con oe ntrates are usually required to Yithstand storage for prolonged periods and after such storage to be capable of dilution Yith ~ater to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be appliec by conventional spray equipment. The con-oer.trates conveniently contain from 20 to 99~, prefer~
ably 20 to 60%, by ~eight of active ingredient.
Emulsion or emulsifiable concentrates are con-~251207 veniently prepared by dissolving the active ingredient in an organic solvent containing one or more surface active agents. Pastes may be prepared by blending the finely divided active ingredient with a finely divided solid carrier, one or more surface active agents and optionally an oil. Oil dispersions may be prepared by grinding together the active ingredient, a hydrocarbon oil, and one or more surface active agents. Aqueous suspension concentrates may con~eniently be prepared by ball milling a mixture of the active ingredient, water, at least one surface active agent and preferably at least one suspending agent. Suitable suspending agents include: hydrophilic colloids such as, for exam~le, poly(N-vinylpyrrolidone), sodium carboxymethylcellulose and the vegetable gums gum acacia and gum tragacanth;
hydrated colloidal mineral silicates such as, for ex-ample, montmorillonite, beidellite, nontronite, hectorite, saponite, sauconite and bentonite; other cellulose derivatives; and poly(vinyl alcohol). ~ett-able powder concentrates may conveniently be prepared byblending together the active ingredient, one or more surface active agents, one or more solid carriers and optionally one or more suspending agents and grinding the ~ixture to give a powder having the reauired particle size.
The aqueous suspensions, dispersions or emulsions ma~ be prepared from the conoentrated com-positions by ~ixing the concentrated compositions with ~ater optionally oontaining surface active agents and~or oils.
It ~hould be noted that the compounds of the invention of formula I wherein Rl is hydrogen are acidic.
Therefore, the com~ounds of formula I ~ay be formulated and applied as the salts of organic or inorgaric bases~
In formulatinc an ~loying the compo~Dds of formula I

~25~07 - 3~ _ in the form of their salts either the salts per se, that is the compounds of formula I wherein Rl is an inorganic or an organic cation, may be usecl in the formulation or ~he compounds of formula I wherein Rl is hydrogen may be used in the formulation and the salts generated in situ by the use of the appropriate organic or inorganic base.
The mode of application of the co~positions of the invention will depend to a large extent on the type of composition used and ~he facilities available for its application. solid compositions may be applied by dust-ing or any other suitable ~eans for broadcasting or sDreadin~ the solid. Li~uid co~positions may be applied by sprayin~, atomizing, watering, introduction into the irrigation water, or any other suitable means 15 for broadcasting or spreading the liquid.
The rate of application of the compounds of the invention will depend on a number of factors includ-ing, for example, the cDmpound chosen for use, the identity of the plants whose growth is to be inhibited 20 the formulations selected for use and whether the com-pound is to ke applied for foliage or root uptake. As a general guide, however, an application rate of from 0.005 to 20 kilograms per hectare is suitable ~hile from 0.01 to'5.0 kilo~rams per hectare may be preferred.
The compositions of the invention ~ay co~prise, in addition to one or more compounds of the invention, one or more compounds not of the invention but which possess biological activity. Por example, as herein-before indicated the compounds of the invention are in general substantially more effective against mono-cotyledonous plants or grass species than against dicotyledonous plants or br~ad-leaved species. As a result, in certain applications the herbicial use of the coGpounds of the inventior. alone ~ay not ke sufficient to protect a crop. Accordingly in yet a s ill further ~25~2~

embodiment the invention provides a herbicidal com-position comprising a muxture of at least one herbicidal compound of formula I as herein~efore defined with at least one othe~ herbicide.
The other herbicide may ~e any herbicide not having the formula I. It will generally be a herbicide having a complementary action. For example, one pre-ferred class is of mixtures comprising a herbicide active against broad-leaved weeds. A second preferred class is of mixtures comprising a contact herbicide.
Example of useful complementary herbicides include:
A. k~nzo-2,1,3-thiadiazin-4-one-2,2-~ioxides such as 3-isopropylbenzo-2,1,3-thiadizin-4-one-2,2-dioxide (common name bentazon), B. hormone her~icides and in particular the phenoxy-alkanoic acids such as 4-chloro-2-methylphenoxy acetic acid Icommon name ~CPA), 2-(2,4-dichloro-phenoxy)propionic acid ~common name dichlorprop), 2,4,5-trichlorophenoxyacetic acid Ico~mon name 2,4,5-T), 4-(4-chloro-2-methylphenox~-)butyric acid (oommon name MCPB), 2,4-dichlorophenoxyacetic acid (CQmmOn name 2,4-D), 4-(2,4-dichlorophenoxy)butyric acid (common name 2,4-DB), 2-(4-chloro-2-methyl-phenoxy)propionic acid Ico~on Dame mecoprop), and their derivatives (eg salts, esters, amides and the like);
C. 3~ l4-halophenoxy)phenyl7~ dial~ylureas such as 3-~4-(4-chlorophenoxy)phenyl7-1,1-dimethylurea (co~r.on name chloroxuron);
D. dinitrophenols and their der~vatives (e~ acetates) SUGh as 2-methyl-4,6-dini~rophenol (co~mon name DNOC), 2-tertiarybutyl-4,6-dinitrophenol Icommon ~25~

name dinoterb), 2-secondarybutyl-4,6-dinitrophenol (co~mon name dinoseb) and its ester dinoseb acetate;
E. dinitroaniline herbicides such as N',N'-diethyl-2,6-dinitro-4-trifluoromethyl-m-phenylenediamine S (common name dinitramine), 2,6-dinitro-N,N-dipropyl-4-trifluoromethyl~niline (common name trifluralin) and 4-methylsulfonyl-2,6-dinitro-N,N-dipropylaniline (common name nitralin);
F. phenylurea herbicides such as N'-(3,4-dichloro-phe~yl)-N,N-dimethyl~7-ea (common name diruon) and N,N-dimethyl-N'-~3-(trifluoromethyl)phenyl7urea (common name fluometuron);
G. phenylcarbamo~loxyphenylcarbamates such as 3-~(methox~carbonyl~amino7phenyl (3-methylphenyl)-carbamate (common na~e phenmedipham) and 3~(ethoxy-oarbonylamino7phenyl phenylcarbamate (common name desmedipham);
H. 2-phe~ylpyridazin-3-ones su~h as 5-~mjno-4-chloro-2-phenylpyridazin-3-one (com~lon nam~ pyrazon);
2Q I~ uracil herbicides such as 3-cyclohexyl-5,6~
trimethyleneuracil (ccmmon name lenacil~, 5-~romo-3-sec-butyl-6-methyluracil (common ~ame bromacil) and 3-tert-butyl-5-chloro-6-methyluracil (com~on name terbacil);
J. triazine herbici~es such as 2-c~loro-4-ethyl2mino-6-(is~propyl~mino)-1,3,5-triazine (co on name atrazine), 2-chlo~o-4~6-dilethyla7~ino~ 3~s-triazine ~co~mon na~.e simazine) an~ 2-azido-4-(iso-propyla~i~o)-6-methylthio 1,3,5-triazine (commcn n~e azipro2tryne~;
R. l-alkoxy-2-al~yl-3-pheaylurea herbicides such ~s ~L25~0~i7 3-(3,4-dichlorophenyl)-1-methoxy l-methylurea (common name linuron~, 3-(4-chlorophenyll-1-methoxy-l-methylurea (common name monolinuron) and 3-(4-bromo-4-chlorophenyl)-1-methoxy-1-methylurea (common name chlorobromuron);

L. thiocarbamate herbicides such as S-propyl dipropyl-thiocarbamate ~common name verolate);
M. 1,2,4-triazin-5-one herbicides such as 4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2,4-tria~ine-5-one (common name metamutron) and 4-aminc-6-tert-butyl 4,5-dihydro-3-methylthio-1,3,4-triazin-5-one (common name metribuzin);
N. benzoic acid herbicides such as 2,3,b-trichloro-benzoic acid (common name 2,3,6-TBA), 3,6-dichloro-2~methyoxyben~oic acid ~common name dicamba) and 3-amino-2,5-dichlorobenzoic acid (common name chlorambe~n);
o. anilide herbicides such as N-butoxymethyl-~-chloro-2',6'-~iethylacetanilide ~common name butachlor), the corresponding N-methoxy compound lcommon name alachlor), the corresponding N-iso-propyl compound (common name propachlor) and 3',4'-dichloro-propionanilide (common name propanil);
P. dihalobenzonitrile herbicides such as Z,6-dichloro-benzonitrile (common name dichlobenil), 3,5-dibro-4-hydroxybenzonitrile (common name bro xynil) and 3,5-diiodo-4-hydroxybenzonitrile ~common name ioxynil).
Q. Hal~alkanoic herbicides such as 2~2-dichloro-propionic acid (common name dalapon), trichloro-acetic aci~ ~common name TCA~ ~nd salts thereof;

~L251Z07 R. diphenylether herbicides such as 4-nitrophenyl 2-nitro-4-trifluoromethylphenyl ether (common name fluorodifen), methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate (c~mmon name bifenox), 2-nitro-5-(2-S chloro-4-trifluoromethylphenoxy)benzoic acid and 2-chloro-4-trifluoromethylphenyl 3-ethoxy-4-nitro-phenyl ether;
S. N-~hetero~rylaminocarbonyl)benzenesulfonamides such as 2-chloro-N-~(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl7ben enesulfonamide (commonly known as DPX 4189); and T. miscellaneous herbicides includins N,N-dimethyl-diphenylacetamide ~common name diphenamid), N-(l-naphthyl)phthalamic acid (common name naptalam) and 3-amino-1, 2,4-triazole.
Examples of useful contact herbicides include:
U. bipyridylium herbicides such as those in which the acti~e entity is the l,l'-dimethyl-4,4'-dipyridylium ion (common name paraquat~ and those in which the acti~e entity is the 1,1'-ethylene-2,2'-dipryidylium ion ~common n~ diquat);
V. organoarsenical berbicides such as ~onosodium ~ethanearsonate (common name HS~); and ~. amino acid herbicides such as ~-~phosphonomethyl)-glycine Icomm~n na~e glyphosate) and its salts and esters.

~LZ~;12C3'~

The invention is now illustrated by, but in no way limited to, the following Examples.
~xample 1 This Example details the preparation of the mono-substituted pyrimidine-5-carboxaldehydes of formula V used in the preparation of compounds of the invention.
(i) {2-/(Dimethylamino)methylene7propanediylidene}
bis~dimethylammonium perchlorate7 was prepared by for~lation of bromoacetic acid following the procedure of Alnold (Collect. Czech. Chem.
Comm., 30, 2125 (1965)).
(ii) A suspension of the above perchlorate salt (14.8 g) and acetamidine hydrochloride (4.0 g) in methanol (200 ml) was stirred at 40C during the gradual addition of a solution of sodium (1.0 g) in methanol (50 ml). After 3 hours the solution was neutralized with acetic acid and evaporated under reduced pressure. The residue was diluted with water (50 ml) and extracted ~ith chloroform (2 x 100 ml). The chlorof~rm extracts were dried and evaporated to give 2-methylpyrimidine-5-carboxaldehyde (2.5 g, 49%).
Theproduct was characterized by proton nuclear magnetic resonance s2ectroscopy and the spectrum i5 recorded in Table 2 below.
The mono-substituted pyrimidine-5-carboxaldehydes of formula V listed in Table 2 below were prepared from {2-~dimethylamino)methyle~e7propanediylidene bis-~dL~ethylam~onium perchlorate7 and the appropriate ~midine hydrochloride follovin~ the proced-mre described ~bo~e for the preparation of 2-æ thylpyrimudine-5-~2S~

carboxaldehyde. The products were characterized by proton nuclear magnetic resonance spPctroscopy and the spectroscopic data are recorded i~ Table 2 below.

X~CHO

X Position of ~ Proton Chemucal Shift ~ in CH0 Group ppm (CDC13) 2-CH3 5_ 2.90 (3H,s); 9.02 (2H,s);
1~.06 tl~,s).
2-CH3S5_ 2.60 (3H,s); 8.87 (2H,s);
9.96 (lH,s).
2-CH3O5_ 4.10 (3~,5); 8.92 (2~,s);
. 9.95 (l~,s).

Example 2 2~ (Ethoxyimino)butyl7-3-hydroxy-5-t2-methyl-5-~rimidyl)cyclohex-2-en-1-one (1) (i) A ~Dlution of 2-methylpyrimidine-5-carboxaldehyde ~4 g) in acetone (50 ml) and ~ater (30 ml) was la treated with a solution of agueous sodium hydroxide ~2~, 5 ml) ~qth stirring at 20C. ~he solution was allowed to stand at room temperature oYernight and then concentrated under reduced pressure and neutralized ~it~ dilute hydrochloric acid. The mixture was extracted dried over anhydrous magnesium sulphate and evaporated under reduced pressure to give l-f 5-(2-~e~hyl-pyri~idyl)~but-l-erl-3-one (2 3 g, ~3~) as a pale broYn oil.

~l25~26~7 (ii) Diethylmalonate (3.9 ml) was added to a stirred solution of ~odium metal (0.56 y) in absolute ethansl ~40 ml) and the solution was heated under reflux. 1-~5-(2-Methylpyrimidyl7but-1-en-3-one ~2.3 g~ was added and the mixture was heated under reflux for a period of 2 hours.
An aqueous solution of sodium hydroxide (2.0 g, 30 ml water) was added and the solution was re-fluxed for a fur~her 5 hours. The hot solution was acidified to pH 4 with concentrated hydro-chloric acid (caxbon dioxide evolution) and then made alkaline ~y the addition of sodium bicarbonate. Evaporation ~f the s~lution to dryness gave the sodium salt of 3-hydroxy-5-~methylpyrLmidylL7cyclohex-2-Pn-l-one (2.3 g, 72~) as a pale brown solid, mp >200C.
(iii) The sodium salt of 3-hydroxy-5-~5-(2-methyl-pyrimidylL7cyclohex-2-en-1-one (2 . O g) was dissolved in dimethylformamide (10 ml) with stirring at 90C. Butyric anhydride (1.4 ml) was added to the solution and the heatin~ was continued at 110C for 1 hour. The dLmethyl-formamude was evaporated under reduced pressure and the residue was dissolved in ~ater (20 ~1) and chloroform (40 ml). The chloroform layer was separated, dried over anhydrous magnesium sulphate and evaporated to give an oil which was purified bX column chromatography over silica gel (eluant chloroform) to give 2-butyry1-3-hydroxy-5~ (2-methylpyrimudyl)7cyclohex-2-en-l-vne (800 mg; 30%~ as an oil.
liv~ Ethoxyamine hydrochloride (240 mg, 2.5 mmol~
a~d then sodiu~ hydroxide ~100 mg) in water (1 ml) were addec to a solution o~ 2-butyry1-3-hydroxy-5-~5-~2-methylpyrimidyl)/cyclohex-2~n-12~ 7 l-one (600 mg; 2.2 mmol) in ethanol (50 ml) with stirring at room temperature. After 20 hours the ethanol was removed ~y evap~ration under reduced pressur~. The residue was S dissolved in chloroform, washed with wat~r and then the organic layer was separated~ dried over anhydrous magnesium sulphate and evaporated to give 2-~I-(ethoxyimino~butyl7-3-hydroxy-5-/5-(2-methylpyrimidyl~7cyclohex-2-en-l-one (600 mg; B7~) a~ a pale brown oil.

The product and each of the intermediates were characterized by proton nuclear resonance spectroscopy and the spectra for the interme~iates and final product are recorded in Examples 11, 12 and 13, Tables 3, 4 and 5.
Example 3 2~ (Ethoxyimino) butyl7-3-hydroxy-5-/5- (2-methylthio-pyrimidyl~cyclohex-2-en-l-one (2) and 2-~1-(ethoxy-imino)butyl7-3-hydroxy 5-~5-(2-methoxypyrimidyl) 7-c~clohex-2-en-l-one (3) were prepared from the appro~riate pyrLmidine-5-carboxaldehyde following essentially the same procedure as that describe~ in ~xample 2 parts (i) to (iv).
Each of the products and intermediates were characterizea by proton nuclear m~gnetic resonance spectroscopy and spectroscopic data are recorded in Examples 11, 12 and 13, Tables 3, 4 and 5.

2-~- (Ethox~L~ino)propyl7-3-hydroxy-5-~5-(2-methyl-tniopyrimid~lL7cyclohex-2-en-l-one ~4) was prepared following esse3tially the same procedure as that des-cribed in Exam~le 2 parts ~i) to (i~) exc~pt for ~he 1~5~207 _ 43 -use of DrOpiOniC anhydride in part (iii) instead of butyric anhydride. The product and intermediate were characterized by proton magnetic resonance spectroscopy and the spectra are recorded in Examples 12 and 1 Tables 4 and S.
Example 5 2-~I- (Ethoxyimino)propyl7-3-hydroxy-5-~5-(2-methyl~
thiopyrimidyl)7cyclohex-2-en-l-o~e sodium salt (5) ~o a solution of 2~ ethoxyimino)propyl7-3-10 hydroxy-5-~5-(2-methylthiopyrimidylL7cyclohex-2-en-1-one (180 mg) in methanol (30 ml) was added a solution of sodium hydroxide in methanol (1.1 ml of a solution o~ 1~0 g in 50 ml methanol). The solution was evaporated under reduced pressure to give the sodium 15 salt (5) of 2-~1-(ethoxyimino)propyl)-3-hydroxy-5-~5-~2-methylthiopyrimidylL7cyclohex-2-en-1-one as a pale brown solid, mp ~200C.
Example 6 2-~l-(Ethoxyimino)propyl7-3-hydroxy-5-~5-(2-meth sulfinylpyrLmidyl)7cyclohex-2-en-1-one (6) A solution of 2-~ ethoxyimino)propyl7-3-hydroxy-5-~5-~2-methylthiopyrimidyl)7cyclohex-2-en-1-one (600 mg) in dichloromethane (10 ml) was treated at 5C with a solution of 3-chloroperbenzoic acid ', 25 (400 mg) in dichlor~methane (30 ml). The solution S allowed to warm to room temperature and to stand for 24 hours. The solvent was removed under reduced pressure and the residue ~as purified by column chroma.ography over silica gel (eluant chloroform) to 30 ~ive 2-~1-(ethoxyLmino)pro2yl7-3-hydroxy-5-~5-(2-~ethylsulfin~lpyrLmidyl)7cyclohex-2-en-lone (6) (300 mg, 46%) as a nearly colourless solid. The 1~51~1~7 product was characterized by proton magnetic resonance spectroscopy and the spectru~ is recorded in Example 13, Table 5.
Example 7 5 2-/~-(3-Chloroallyloxy)butyl7-3-hydroxy-5-~5-(2-methylpyrimidylL/cyclohex-2-en-1-one (7) was prepared from 2-butyryl-3-hydroxy-5-~5-(2-methylpyrimidyl) 7-cyclohex-2-en-1-one and 3-chloroallyloxyamine following essentially the same procedure as that described in Ex-ample 2, part (iv1. The product was characterized by proton magnetic resonance spectroscopy and the spectrum is recorded in Example 13, Table S.
Example 8 3-Trimethylacetyloxy-2-~I-(ethoxyimino)butyl7-5-15 ~5-(2-methoxypyrimidyl)7cyclohex-2-en-1-one (8) Trimethylacetylchloride ~0.10 g) was added ~ith stirring to a solution of 2-~1-(ethoxyLmino)-butyl7-3-hydroxy-5-~5-(2-methoxypyrimidyl)7cyclohex 2-en-1-one (3) (0.15 g) and 3-picoline (0.10 g) in dichloromethane (10 ml) at room temperature. After 2 hours at room temperature the solution was washed ~ith dilute hydrochloric acid ~lM, 10 ml), separated, dried o~er anhydrous magnesium sulphate and evaporated under reduced pressure to give 3-trimethylacetyloxy-2-25 ~1-(ethoxyimino)butyl7-5-~5-(2-methoxypyrimidyl) 7 cyclohex-2-en-1-one (~) as a colourless oil (15G mg).
The productwas characterized by pro~on magnetic resonance spectrosco2y and the spectroscopic data is recorded in Table 5, Example 13.

~2SlZO~

Example 9 2-~I- (Ethoxyimino~propyl7-3-hydro~y-5-/5-(2-dimeth aminopyrimidyl~7cyclohex-2-en-l-one 1 9) was isolated -by chromatography during the purificatîon of 2-~I-(ethoxyimino)propyl7-3-hydroxy-5-/5-~2-methylthio-pyrimidyl)7cyclohex-2-en-1-one (4) Presumably the dimethylamino group was introduced during the acylation step (Example 2 part (iii)) which is carried out in dimethylformamide at 110C.
The campound was characterized by prc>ton nuclear magnetic resonance s2ectroscopy and the spectrum is recoxded in Example 13, Table 5.
xample 10 2-~I- [Ethoxy~mino)propyl7-3-hydroxy-5-~2-(5-methyl-~yrimidyl)7cyclohex-2-e~ one (10~
(i) 2-Hydroxymethyl-5-methylpyrimidine was prepared by the reaction of 3-ethoxy-2-methyl acrolein and hydroxyacet~ridine hydrochloride following a similar procedure to that described by Kim and McRee ~J. Ors. Chem., 35, 455 (1970)).
Proton magnetic resonance spectrum (CDC13; ~ in ppm): 2.32 (3~,s); 3.6 llH,bs); 4.80 l2B,s);
8.54 ~2~,s~.
(ii) 5-MethylpyrLmidine-2-car~oxaldehyde was prepared from ~-hydroxymethyl-5-methylpyrLmidine by oxidation ~ith eYcess manganese dioxide in boil-ing chloroform. Ihe product was obtained as colourless crystals an~ ~as characterized ~y proton nuclear ha~ne.ic resonance spectroscopy.
Proton nuclear ~2~netic reconance spectrum ICDC13; ~ in ppm~: 2.44 ~3~,s); 8.80 12H,s);
10.06 (lH,s).

125~Z07 (iii) 2~ (Ethoxyimino)propyl7 3 hydroxy-5-~2-(5-methylpyrimidylL7~yclQhex-2-en-1-one (18) was prepared from 5~methylpyrimidine-2-carboxaldehyde followiny essentially the same procedure as that described in Example 2 partsi (i) to ~iv). ~ach intermediate and the product was characterized by proton magnetic resonance spectroscopy and these are recorded in Examples 11, 12 and 13, Table 3, 4 and 5.
Exam~le 11 The l-~mon~-substituted pyrimidyl)but-l-en-3-ones of formula VIa used in the preparation of the compounds of formula I ~ere characterized by their proton nuclear magnetic resonance (pmr) spectra. For convenience the pmI data are recorded in Table 3 below.

(X)n ~ C~=CHCOC~3 VIa (X) Position of Proton Chemical Shift n enone group ~ in ppm (CDC13~

2-CB3 5 2.39(3~,s), 2.75(3~,s); 7.08 (2~,dofa~; B.74~2~,s).

2-CH3S 5 2.35(3H,s1; 2.55(3~,s); 7.04 (2~,dofd); 8.61(2H,s).
2-C~30 5 ! 2 38(3~ s); 4 04(3~ s); 7 04 , (2~,dofd)~ 8.65(2~,s).
5-C~3 2 , 2.35(~,s); 2.43(3H,s); 7.2-. i 7.8~2~,D~; 8.57(2~,s).

~25:12~)~

~xample12 The 2-acy1-5-(mono-substituted pyrimidyl)cyclo-hexan 1,3-diones of formula XIII used in the preparation of compounds of formula I were chara~terized by their proton nuclear magnetic resonance spectra. For con-venience the pmr data are recorded in Tatle 4 below.
The majority of ~he compounds were obtained as oils or low-melting point solids and were generally colourless or ~ale brown.
~ABLE 4 (X ~ R3 . Po6ition of Prot~n Chemical Shift Substituents Pyr~dine ~ in ppm ~ 13) ~X~n = 2 C~3 1.00(3B,t); 1.7~2B,m);
R = n-C3H7 2.71(3E,s); 2.6-3.6(7H,m);
8.52~2~,s); 18.27(L~,s) (X~ = 2-C~3S 5 0.99(3~,t~; 1.7(2H,m);
R = n-C3~7 2.55(3H,s); 2.5-3.6(7~,m);

8.39(2~,s); 18.27llH,s).
~X) = 2-C~3O 5 0.99(3H,t); 1.7(2E,m);
R = n-C3H7 2.6-3.6(~B,~); 3.98(3~,s);
8.39(2B,s); 18.2(1ff,s).
~X)n = 5 C~3 2 1.13(3E,t); 2.30(3E,s);
, R = C2B5 2.4-3.9(7~,~); 8.50(2H,s);
18.16(1~,s).
(X)" = 2-C~3S 5 1.16(3H,~); 2.53(3~,s);
R = C2B5 2 5-3 S~7E ~); 8.40~2~,s);

~L25~ZO~

The maiority of the ~ono-substituted pyrimudyl compounds of the invention ~ere obtained as cslourless or light brown oils or low-~elting point solids and were characterized by and can be identified by their nuclear magnetic resonance spectra. For convenience proton nuclear magnetic resonance spectroscopic Ipmr) data are recorded in Table S below.

. _ _ .

Canpound Proton Chemi ca 1 Shi f t No~ in pprn (CDC13) 1 0.99(3H~t~; 1.34(3Hrt); 1.7(2H,m); 2.70 (3H,s); 2.6-3.6(7H,m); 4.11(2H,q); 8.50 (2B,s); 15.6(1~,bs).
2 O.9B(3~,t); 1.33(3~,t); 1.7~2H,m); 2.56 ~3H,s); 2.5-3~7(7H,m); ~.12(2H,q); 8.44 (2H,s); 15.5~1~,bs).
3 0.99(3~,t); 1.33(3H~t); 1.6(2H,m); 2.5-3.6 ~7H,m); 4.oo(3a~s); ~.12(2H,q); 8.43(2~,s);
15.5(lH,~s).
4 1.16(3~,t); 1.34(3E,t); 2.56(3H,s); 2.5-3.6 (7H,m); ~.13(2~,q); 8.44(2B,s); 15.011B,bs).
Not recor~ed Ç 1.16(3~,t); 1.33(3~,t); 2.5-3.7(7H,m);
2.98(3B,s); 4.12~Z~,g~; 8.77(2H,s); 15.0 (l~,bs).
7 0.98(3~,t); 1.6(2~,m); 2.72(3B,s); 2.6-3.6(7H,m3; 4.67(2~,dofd); 5.8-6.412H,~);
8.48(2H,s); l5 0~1~,bs).

~25~20~
_ 49 -TABLE 5 - eontinued .__ _ ,...... _. ... .
Proton Chemucal Shift Compound ~ in ppm (CDC13) __._ _ __. _ 8 0.98(3H,t?; 1.2519H,s~; 1.34(3H,t); 1.6 (2H,m); 2.5-3.6(7~,m); 4.00(3H,s); 4.12 (2~,q); 8.45(2H,s).
9 1.15(3H,t) 1.34(3H,t) 2.5-3.6(7H,m); 3.17 ~6H,s); 4.12(2~,q); B.25(2~,s); 15.0(1H,bs) 1.12(3~,t); 1.33(3~,t); 2.33(3~,s); 2.5-3.8(7H,m); 4.12(2H,q~; 8.47~2~,s); 14.8 _ _ (lH,bs).

ExamRle 14 This DOn-limiting Example illustrates the pre-paration of formulations of the compounds of the in-vention.
a) Emulsifiable Concentrate Compound No 1 was dissol~ed in toluene containing7% v/v ~Teric~ ~13 and 3~ v/v ~Remmat~ SC15B to give an emulsifiable concentrate ~hich may be di-luted with ~ater ~o the reguired conoentration to give an aqueous e~ul~ion which ~ay be applied by spraying.
S'Teric~ is a ~rade ~ar~ and ~Teric~ N13, is aproduct of ethoxylation of nonylphenol; ~Kemmat~ is a Trade ~ark and ~Kemma~ SC15B is a formulation of calcium dodecyIbenzenesulfonate.) ~251;~0~

b) ~4ueous Suspension Ccmpound No 1 ~5 parts by ~eight) and ~Dyapol" PT
(1 part by weight) ~ere adde~ to an aqueous solution (94 parts by weight) of ~Teric~ N8 and the mixture ~as ball milled to produce a stable aqueous sus~
pension which may be diluted with ~ater to the re-quired concentration to give an a~ueous suspension ~hich may be applied by spraying. ("Dyapol" is a Trade Mark and ~Dyapol~ PT is an anionic suspending agenti VTeric~ n8 is a product of ethoxylation of nonylphenol.) c) Emulsifiable Concentrate Compound Nol(10 parts by weight~, ~Teric" N13 (5 parts by weight) and ~Remmat~ SC15B (5 parts by weight) were dissolved in ~Solvesso~ 150 (80 par~s by weight) to ~ive an emulsifiable concentrate ~hich ~ay be diluted with water to the required con-centration to give an aqueous emulsion which may be applied by spraying. (~Solvesso~ is a Trade Mark and ~Sslvesso~ 150 is a high boiling point aromatic petroleum fraction . ) d~ Di~persible Powder Compound No 1 (10 parts by ~eight), nMatexil~ DA/AC
(3 parts by weight), 'Aerosol~ OT/B (1 part by ~eight) and china clay 298 (86 parts by weight~
~ere blended and the~ Qilled to give a powder com-position having a particle size below 50 microns.
(~ffa~exil~ is a Trade ~ark and 'Matexil" DA/AC is the disodium salt of a naphthalenesulfonic acid~
forDaldehyde concensate; Aerosol- is a Traae ~ark and ~A2rosol~ OT/B is a f~nmulation of the dioctyl ester of sodium sulfosucci~ic acid.) ~L2S~ 7 -- ;l e) ~i2~h Strength ~oncentrate Compound No 1 (99 parts by weight), ~ilica aerogel ~O.5 parts by weight) and synthetic ~morphous silica (0.5 parts by ~eight) were blended and ground in a hammer-mill to produce a powder h~ving a particle size less than 200 microns.
f) Dustiny ~owder Compound No 1 llO parts by weight1, attapulgite (10 parts by weight) and pyrophyllite (8~ part~i by lQ weight) were ~horoughly blended and then grvund in a hammer-mill to produce a powder of particle size less than 200 microns.
Emulsifiable con oe ntrates and/or suspensions of tbe com?ounds of the invention were prepared essentially as described in part a), b) or c) above and then dilubed with water, optionally containing surface active agent and/or oil, to give aqueous coTpositions of the required concentration ~hich were used, as described in E~amples 15 and 16, in ~he evaluation of the pre-ecærgence and post-~mergence herbicidal ac~ivity of the compo~n~s.
E~ample 15 The pre-emergent herbicidal actiYity of the com-pounds of the invention formulated as described in Exanple 14 ~as assessed by he follo~ ~ g procedure:
The seeds of the test species were ~own in ro~s 2 c~ deep in soil contained in seed boxes. me wno-co~ledonous plants and the dicotyledc~nous pla~ts ~ere so~n in separate boxes and af ter ~ ing the t~o bo: ces 30 ~ere ~;prayed ~ith t~e required qua~ y of a composition of t~e irvention . Two dupl i cate seed bo~es were pre-~25~L2~37 pared in the same manner but ~ere not ~prayed with a composition of the invention and ~ere used for com~
parison purposes. All the boxes were placed in a glass-house, lightly ~atered with an overhead spray to iDitiate germination and then sub-irrigated as required for optimum plant growth. After three weeks ~he boxes were removed frQm the glass house and the effect of the treatment was visually assessed. The results are pre-sented in Table 6 where the damage to plants is rated 10 on a scale of form O to 5 where O represents ~rom o to 10% damage, 1 represents from 11 t~ 30% damage, 2 represents from 31 to 60~ damage, 3 represen~s from 61 to 80~ damage, 4 represents from 81 to 99% damage and 5 represents 100X kill. A dash (-) means that no experi-5 ment was carried out.The names of the test plants are as follows:
~h Wheat Ot ~ild Oats Rg Ryegrass 3m Japanese millet P Peas Ip Ipomea Ms ~ustard Sf Sunflower ~;~5~2~

T~I~: 6 PRE-EMEROE:NOE EIERBICIDAL I~TI~ITY
. _ .

pOumnd ~PLI ~TION l~:ST PI~NT
No Rate ~kg/ha) ~ . . _ _. _ Wh Ot Rg Jm P Ip Ms S f _ ..~ ___ __ 1 1.0 4 ~ 5 5 O O O
3 1.0 4 5 ~ 5 0 0 0 0 3 0.25 2 3 4 3 ~ 0 0 0 4 1.0 3 5 5 5 0 0 0 0 1.0 5 5 5 5 û O O 0 Example 1 ~
The post-enPrgent herbicidal activity of the cc~pounds of the inverltion :Eormulated as described in 5 Ex2~le 14 ~as assessed b~ the foll~iing procedure.
The seeds of the tes t species ~ere sown in rs~ws 2 cm deep in soil cc~Tltained in seed boxes. The ~onocotyleds:lnous plants and the dico~ledonous plants ~ere sa~ eparate seed boxes in d~ ate. The 10 four seed boxes ~ere placed in ~ glass house, lightly 7ratered with an overhea~l spray to initia~e germination a~d then sub-irri~ated as reguired for optimum plant growth. After the plar~ts had gr~ bD a heiqht of ~bout 10 to 12 . 5 c~m one }:~ox of each of the mono-15 ootyledonous plants and diootyledonous plants wasremoved fron~ the glass house aDd sprayed ~ith the re-~ired qua~tity of a cc~posi~ion of ~h~ invention.

~25~20'7 After spraying the boxes ~erc returned to the glass house for a further 3 weeks and the effect of treat-ment was visually as~essed by ca~parison with the un-treated contols. ~he results are presented in Table 7 where the damage to plants is rated on a scale of from 0 to 5 where 0 represents from 0 to 10% damage, 1 represents from 11 to 30% damage, 2 represents from .
31 to 60% da~age, 3 represents from 61 to 80% damage, 4 represents frQm 81 to 99% damage and 5 represents 100~ kill~ A dash (-~ means that no experiment ~as carried out.
The names of the test plants are as follows:
Wh ~heat Ot ~ild Oats Rg Ryegr cs 3m Japanese millet P Peas Ip Ipa~ea ~s Mustard Sf Sunfl~er 3l ;2 5 1i~ldV7 -- ~5 --POST-EMERGENOE HEP~BICIDAL ACTIVITY

TES T PLANT
Com-- APPLI CATION
pound Rate (kg~ha~ __ ___ _ ~h OtRg Jm P Ipl~s S f ___ ~ _ 1 1.0 5 5 5 5 0 0 0 0 1 0.25 S 5 ~ 5 0 0 0 0 1 0.06 3 5 5 5 0 0 0 0 2 1.0 0 5 5 4 0 0 0 0 2 0.25 0 ~ 4 3 0 ~ 0 0 3 1.0 5 5 5 5 0 0 0 0 3 0.25 4 5 5 S 0 0 0 0 3 0.06 2 5 4 4 0 0 0 0 4 1.0 5 5 5 5 0 0 0 0 4 0.25 5 5 5 5 0 0 0 0 4 0.06 3 4 5 5 0 0 0 0 1.0 5 5 5 5 0 0 0 0 0.25 5 ~ 5 5 O O O û
0.06 3 3 ~ 4 0 0 0 0 1~ 1.0 3 5 5 5 0 0 0 0 ~) 0.25 1 3 _ 3 O 0 0 O

125~ 37 _ 56 -Example 17 me c~mpounds were formulated for test by mixing an appr~priate amount with 5 ml of an emulsion prepared by diluting 160 ml of a solution containing 21.9 g per litre of "Span~ 80 and 78.2 g per litre of ~Tween~ 20 in methylcyclohexanone to 500 ml with water.
"Span~ 80 is a Trade Mark for a surface-active agent comprising sorbitan monolaurate. ~ween" 20 is a ~rade Mark for a surface-active agent comprising a condensate of ~orbitan monolaurate with 20 molar proportions of ethylene oxide. Each 5 nl emulsion containing a test compound was then diluted to 40 ml with water and ~prayed on to yo~ng pot plants (post-emergence test) of the species named in Table 8 below. Damage to test plants was assessed after 14 days on a scale of 0 to 5 where 0 is 0 to 2~% damage and 5 is is complete ~ill.
In a test for pre-emergence herbicidal activity, seeds of the test plants were s~wn in a shallow slit formed in the surface of soil in fibre trays. ffle surface was then levelled and sprayed, and fresh 50il then spread thinly over the sprayed surface. Assessment of herbi-cidal damage was carried out after 21 days using the same scale of 0 to 5 as the post-emergence test. In both cases the degree of herbicid~l damage ~as assessed by co~parison with untrea~ed control plants. The re-sults are given in Table 8 below. A dash (-~ means that no experiment was carried out.
The names of tbe test plants ~ere as follows:
Sb Sugar beet Rp Rape Ct Cot~on Sy Soy bean ~z ~ ze ~w ~inter ~he~t ~L253 ~

Rc Rice Sn Senecio vulgaris Ip Ipomea plLrpurea Am Amaranthus retroflexus Pi Polygonum aviculare Ca Chenopodium al~um Ga Galium aparine Xa Xanthium pensylvanicum Ab Abuti 70n theophrasti Co Cassia obtusîfolia A~ Avena fatua Dg Digitaria sanguinalis Al Alopecurus myosuroides St Setaria viridis ~c Echinochloa crus-~alli Sh Sorghum hale~ense Ag ~gropyron repens Cn Cyperus rotundas 125~207 ABLE 8 - PAR~ A
_ ._ _ ___ _ Cn- APPLI CATIONTEST PLANT
pound ~4e'cht>d Rate _ _ __ I_ llo (~g~ha) Sb ~P Ct Sy Mz Ww Rc Sn Ip Am 1 POST O.1_ _ _ _ 5 4 4 _ _ _ _ 1 POST 0. 0 2 _ _ _ _ 3 3 3 _ _ _ 2 PE~: Q . 4 _ _ _ _ _ tl _ _ _ _ _ _ 2 POST 0.05 _ _ _ _ 1 O O _ _ _ _ _ 3 }'OS T 0 . 0 5 _ _ _ _ 3 O 4 _ _ _ _ _ 3 POST Q . 0 2 _ _ _ _ 2 O O _ _ _ _ _ ~2S121D7 _ 59 ---- _ _ . .

Ca~- APPLICATION TEST PLA~r pound Method R~te No (kg/ha) Ga Xa Ab Co ~v Dg Al St Ec Sh Ag Cn _ ...... _ __ _ _ _ ~ POST 0 . 1 _ _ _ _ 4 4 5 5 4 ~ ~
1 POST 0.02 _ _ _ _ 4 4 4 4 3 4 O _ PRE 0.~ _ _ _ _ 3 _ 5 _ _ _ _ _ 2 POST 0 . 0 5 _ _ _ _ 4 3 4 4 4 3 O
3 POST 0 . OS _ _ _ _ 4 4 4 4 5 4 4 3 POST 0.,02 _ _ _ _ 3 3 4 4 4 3 O _

Claims (13)

1. A compound of formula I

wherein:
x, which may be the same or different, are independently selected from the group consisting of: halogen; nitro cyano; C1 to C6 alkyl C1 to C6 alkyl substituted with a substituent selected from the group consisting of halo-gen, nitro, hydroxy, C1 to C6 alkoxy and C1 to C6 alkyl-thio; C2 to C6 alkenyl; C2 to C6 alkynyl; hydroxy; C1 to C6 alkoxy; C1 to C6 alkoxy substituted with a sub-tuent selected from halogen and C1 to C6 alkoxy; C2 to C6 alkenyloxy: C2 to C6 alkynyloxy; C2 to C6 alkanoyl-oxy; (C1 to C6 alkoxy) carbonyl: C1 to C6 alkylthio; C1 to C6 alkylsulfinyl; C1 to C6 alkylsulfonyl; sulfamoyl N-(C1 to C6 alkyl)sulfamoyl; N,N-di(C1 to C6 alkyl)-sulfamoyl; benzyloxy; substituted benzyloxy wherein the benzene ring is substituted with from one to three sub-stituents selected from the group consisting of halogen, nitro; C1 to C6 alkyl, C1 to C6 alkoxy and C1 to C6 haloalkyl the group NR5R6 wherein R5 and R6 are in-dependently selected from the group consisting of hydrogen, C1 to C6 alkyl, C2 to C6 alkanoyl, benzoyl and benzyl; and the group of the formula -C(R7)-NR8 wherein R7 is chosen from hydrogen and C1 to C5 alkyl, and R8 is chosen from hydrogen, C1 to C6 alkyl, phenyl, benzyl, hydroxy, C1 to C6; alkoxy, phenoxy and benzyloxy;
R1 is selected from the group consisting of: hydrogen;
C1 to C6 alkyl; C2 to C6 alkenyl C2 to C6 alkynyl;

substituted C1 to C6 alkyl wherein the alkyl group is substituted with a substituent selected from the group consisting of C1 to C6 alkoxy, C1 to C6 alkylthio, phenyl and substituted phenyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio; C1 to C5 (alkyl) sulfonyl; benzenesulfonyl; substituted benzenesulfonyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl; C1 to C6 alkoxy and C1 to C6 alkylthio; C2 to C6 alkanoyl; benzoyl; substituted benzoyl wherein the benzene ring is substituted with from one to three substituents chosen from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio, 2-furoyl; 3-furoyl; 2-thenoyl; 3-thenoyl; and an organic or inorganic cation selected from the alkali metal ions, the alkaline earth metal ions, the transition metal ions and the ammonium ion R9R10R11R12N? wherein R9, R10, R11 and R12 are independently selected from the group consisting of: hydrogen, C1 to C10alkyl: substituted C1 to C10 alkyl wherein the alkyl group is substituted with a substituent selected from the group consisting of hydroxy, halogen and C1 to C6 alkoxy; phenyl; benzyl; and the groups substituted phenyl and substituted benzyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio;

R2 is selected from the group consisting of: C1 to C6 alkyl;
C2 to C6 alkenyl, C2 to C6 haloalkenyl; C2 to C6 alkynyl; C2 to C6 haloalkynyl; substituted C1 to C6 alkyl wherein the alkyl group is substituted with a substituent selected from the group consisting of halogen, C1 to C5 alkoxy, C1 to C6 alkylthio, phenyl and substituted phenyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio;
R is selected from the group consisting of: C1 to C6 alkyl;
C1 to C6 fluoroalkyl; C2 to C6 alkenyl; C2 to C6 alkynyl; and phenyl;
R4 is selected from the group consisting of: hydrogen;
halogen; cyano; C1 to C6 alkyl; and (C1 to C6 alkoxy)-carbonyl; and n is an integer selected from 1 and 2.

2. A compound according to claim 1 wherein:
X is selected from the group consisting of C1 to C6 alkyl, C1 to C6 alkoxy, C1 to C6 alkylthio, halogen, C1 to C6 haloalkyl, amino, C1 to C6 alkylamino and di-(C1 to C6 alkyl) amino;
R1 is selected from the group consisting of: hydrogen;
C1 to C6 alkyl; C2 to C6 alkenyl; C2 to C6 alkynyl;
substituted C1 to C6 alkyl wherein the alkyl group is substituted with a substituent selected from the group consisting of C1 to C6 alkoxy, C1 to C6 alkylthio, phenyl and substituted phenyl wherein the benzene ring substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio; C1 to C6 (alkl)sulfonyl;
benzenesulfonyl; substituted benzenesulfonyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 halo-alkyl; C1 to C6 alkoxy and C1 to C6 alkylthio; C2 to C6 alkanoyl; benzoyl; substituted benzoyl wherein the benzene ring is substituted with from one to three sub-stituents chosen from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio 2-furoyl; 3-furoyl; 2-thenoyl; 3-thenoyl; and an organic or in-organic cation selected from the alkali metal ions, the alkaline earth metal ions, the transition metal ions and the ammonium ion R9R10R11R12N? wherein R9 R10, R11 and R12 are independently selected from the group consisting of: hydrogen; C1 to C10 alkyl:
substituted C1 to C10 alkyl wherein the alkyl group is substituted with a substituent selected from the group consisting of hydroxy, halogen and C1 to C6 alkoxy; phenyl; benzyl; and the groups substituted phenyl and substituted benzyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio:
R is selected from the group consisting of: C1 to C6 alkyl; C2 to C6 alkenyl; C2 to C6 haloalkenyl; C2 to C6 alkynyl; C2 to C6 haloalkynyl; substituted C1 to C6 alkyl wherein the alkyl group is substituted with sub-stituent selected from the group consisting of halogen, C1 to C6 alkoxy, C1 to C6 alkylthio, phenyl and substituted phenyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 haloalkyl, C1 to C6 alkoxy and C1 to C6 alkylthio;
R3 is selected from the group consisting of C1 to C6 alkyl, C1 to C6 fluoroalkyl, C2 to C6 alkenyl, C2 to C6 alkynyl and phenyl;
R4 is hydrogen;
n is selected from the integers 1 and 2.

3. A compound according to claim 1 wherein:
X are independently selected from the group consisting of C1 to C6 alkyl, C1 to C6 alkoxy, C1 to C6 alkylthio;
C1 to C6 alkylsulfinyl, C1 to C6 alkylsulfonyl, halogen, amino, N-(C1 to C6 alkyl)amino and N,N-di(C1 to C6 alkyl)amino;
R1 is selected from the group consisting of: hydrogen;
C2 to C6 alkanoyl; benzoyl and substituted benzoyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, C1 to C6 alkyl and C1 to C6 alkoxy;
benzenesulfonyl and substituted benzenesulfonyl wherein the benzene ring is substituted with from one to three substituents selected from the group consisting of halogen, nitro, C1 to C6 alkyl and C1 to C6 alkoxy; and an inorganic or an organic cation selected from the alkali metals, the alkaline earth metals, the transition metals, the ammonium ion and the tri- and tetra- (alkyl) ammonium ions wherein alkyl is selected from C1 to C6 alkyl and C1 to C6; hydroxyalkyl;

R2 is selected from the group consisting of: C1 to C6 alkyl, C2 to C6 alkenyl, C2 to C6 alkynyl, C1 to C6 haloalkyl, C2 to C6 haloalkenyl and C2 to C6 halo-alkynyl;
R3 is selected from C1 to C6 alkyl;
R4 is selected from hydrogen and halogen; and n is an integer selected from 1 and 2.

4. A compound according to claim 3 of formula III
wherein:

III

wherein:
X are independently selected from the group consisting of C1 to C6 alkyl, C1 to C6 alkoxy, C1 to C6 alkylthio, C1 to C6 alkylsulfinyl, C1 to C6 alkylsulfonyl, halogen, amino, N-(C1 to C6 alkyl)amino and N,N-di(C1 to C6 alkyl) amino;
R1 is selected from the group consisting of hydrogen, C2 to C6 alkanoyl, benzoyl, the alkali metals, the transition metals, the ammonium ion and the tri- and tetra- (alkyl)ammonium ions wherein alkyl is selected from C1 to C6 alkyl and C1 to C6 hydroxyalkyl;
R2 is selected from the group consisting of: C1 to C3 alkyl, C1 to C3 haloalkyl, allyl and haloallyl;
R3 is selected from C1 to C3 alkyl;
R4 is hydrogen; and n is an integer selected from 1 and 2.

5. A compound according to claim 4 wherein:

X are independently selected from the group consisting of C1 to C6 alkyl, C1 to C6 alkoxy, C1 to C6 alkylthio and N,N-di(C1 to C6 alkyl)amino;
R1 is selected from the group consisting of hydrogen, C2 to C6 alkanoyl and the alkali metals R2 is selected from the group consisting of C1 to C3 alkyl, allyl and haloallyl;
R3 is selected from C1 to C3 alkyl;
R4 is hydrogen; and n is the integer 1.

6. A compound according to claim 5 of formula IIIa IIIa wherein:
X is independently selected from the group consisting of C1 to C6 alkyl, C1 to C6 alkoxy, C1 to C5 alkylthio, C1 to C6 alkysulfinyl and N,N-di(C1 to C6 alkyl)amino;
R1 is selected from the group consisting of: hydrogen, C2 to C6 alkanoyl and the alkali metals;
R2 is selected from the group consisting of: C1 to C3 alkyl, allyl and haloallyl;
R3 is selected from C1 to C3 alkyl; and R4 is hydrogen.

7. A compound according to claim 6 wherein:

X are selected from the group consisting of methyl, methoxy, methylmercapto and N,N-dimethylamino;
R1 is selected from the group consisting of hydrogen, C2 to C6 alkanoyl, sodium and potassium;
R2 is selected from the group consisting of ethyl, n-propyl, allyl and chloroallyl;
R3 is selected from ethyl and n-propyl; and n is the integer 1.

8. A compound according to claim 7 selected from the group consisting of:

2-[1-ethoxyimino)butyl]-3-hydroxy-5-[5-(2-methyl-pyrimidyl)]cyclohex-2-en-1-one;
2-[1-(ethoxyimino)butyl]-3-hydroxy-5-[5-(2-methylthio-pyrimidyl)]cyclohex-2-en-1-one; and 2-[1-(ethoxyimino)butyl]-3-hydroxy-5-[5-(2-methoxy-pyrimidyl)]cyclohex-2-en-1-one.

9. A herbicidal composition comprising as active ingredient a compound as defined according to claim 1 and a carrier therefor.

10. A process for severely damaging or killing un-wanted plants which process comprises applying to said plants, or to the growth medium of said plants, an effective amount of a compound as defined according to claim 1.

11. A process for selectively controlling the growth of monocotyledonous weeds in dicotyledonous crops which process comprises applying to said crop, or to the growth medium of said crop, a compound as defined accord-ing to claim 1 in an amount sufficient to severely damage or kill said weeds but insufficient to substantially damage said crop.

12. A process according to claims 10 or 11 wherein the compound is applied at a rate in the range of from 0.005 to 20 kilograms per hectare.

13. A process for the synthesis of a compound of formula I as defined according to claim 1 which process comprises:

reacting 2-acyl-5-(aryl)cyclohexane-1,3-dione derivative of formula XIII with an alkoxyamine derivative of formula XVII to give a compound of the invention of formula II or reacting the 2-acyl-5-(aryl)cyclohexane-1,3-dione derivative of formula XIII with hydroxylamine and alkylating the oxime intermediate of formula XVIII
with an alkylating agent of formula XIX, wherein L is a leaving group, to give a compound of the invention of formula II;

H2NOR2 XIII XVII
R2L
XVIII XIX
and, optionally, reacting the compound of the invention of formula II

II wherein 0 represents the group with a compound of formula XX, wherein L is a leaving group, to give a compound of the invention of formula I.

R1L XX I