ZA200508342B

ZA200508342B - 3-Carbonylaminothiophenes and their use as fungicides

Info

Publication number: ZA200508342B
Application number: ZA200508342A
Authority: ZA
Inventors: Ehrenfreund Josef; Walter Harald; Tobler Hans; Lamberth Clemens
Original assignee: Syngenta Participations Ag
Priority date: 2003-05-07
Filing date: 2005-10-14
Publication date: 2007-02-28
Also published as: GT200400089A; CN1784399A; GB0310464D0

Description

3-CARBONYLAMINOTHIOPHENES AND THEIR USE AS FUNGICIDES

The present invention relates to novel thiophene-3-amides, substituted in the 2- or 4- position of the thiophene ring by a silicon containing substituent, which have microbiocidal activity, in particular fungicidal activity. The invention also relates to the preparation of these compounds, to novel intermediates used in the preparation of these compounds, to agrochemical compositions which comprise at least one of the novel compounds as active ingredient, to the preparation of the compositions mentioned and to the use of the active ingredients or compositions in agriculture or horticulture for controlling or preventing infestation of plants by phytopathogenic microorganisms, preferably fungi.

Certain thiophene amides, substituted by a silicon containing substituent, are disclosed in US 5739338 and WO 97/19062. :

The present invention provides a compound of formula (I)

X S_(R%,

Boon where Het is a 5- or 6-membered heterocyclic ring containing one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, the ring being substituted by one to three groups R* R! is hydrogen, optionally substituted (C)4)alkyl, formyl, optionally substituted (C).4)alkylC(=0), optionally substituted (Ci.4)alkylC(=0)O, optionally substituted (C14)alkoxy(Cys)alkyl, optionally substituted allyl, optionally substituted propargyl or optionally substituted allenyl; each R? is, independently, halogen, optionally substituted (Ci4)alkyl, optionally substituted (C,4)alkoxy or optionally substituted (Cy.4)alkoxy(Cy.a)alkyl;

R? is either at position 2 or at position 4 of the thiophene ring and is an organic group containing three to thirteen carbon atoms and at least one silicon atom and, optionally, one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, and is optionally substituted by one to four independently selected halogen atoms; each R* is, independently, halogen, C,.3 alkyl, Ci.3 haloalkyl, C,.;alkoxy(C.3)alkyl or cyano; ris 0, 1 or 2; and X is O or S; or an N-oxide thereof.

In another aspect the present invention provides a compound of formula (I) as defined above provided that the Het ring is not 1,2,3-triazole when X is O.

Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine.

Each alkyl moiety is a straight or branched chain and is, for example, methyl, ethyl, n-propyl, n-butyl, iso-propyl, n-butyl, sec-butyl, iso-butyl or tert-butyl.

The alkenyl moieties, where appropriate, can be of either the (E)- or (Z)-configuration.

When present, each optional substituent on alkyl moieties, allyl, propargyl and allenyl is, independently, selected from halogen, hydroxy, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, methoxy, ethoxy, methylsulfonyl, ethylsulfonyl, difluoromethoxy, trifluoromethoxy and trifluorothiomethoxy.

Preferably R' is hydrogen, propargyl, allenyl, formyl, CH;C(=0), C,HsC(=0) or

CH30CH,C(=0). :

More preferably R' is hydrogen, propargyl, allenyl, CH;C(=0), C,HsC(=O) or

CH;OCH,C(=0).

Most preferably R! is hydrogen.

Preferably, each R? is independently selected from halogen, methyl, trifluoromethyl and trifluoromethoxy.

It is preferred that Hét is pyrazolyl, pyrrolyl, thiophenyl, furyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, 5.6-dihydropyranyl or 5.6-dihydro-1.4-oxathiinyl (more preferably pyrazolyl, pyrrolyl, thiophenyl, faryl, thiazolyl, oxazolyl, 1,2,3-triazolyl, pyridinyl, pyrimidinyl, pyridazinyl, 5.6- dihydropyranyl or 5.6-dihydro-1.4-oxathiinyl) each being substituted by one to three groups

R.

Preferably R? is an aliphatic, saturated or unsaturated group containing three to thirteen carbon atoms and at least one silicon atom and, optionally, one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, and is optionally substituted by one to four independently selected halogen atoms.

More preferably R? is Y'-Si(0,,Me)(0:Me)(0,Y?) where m, n-and p are each, independently, OQ or 1; Y! is a bond or is alkandiyl (alkylene), alkendiy! (alkenylene) or alkindiy! (alkynylene), each of which is branched or unbranched and contains 1-6 carbon atoms optionally interrupted by one or two oxygen atoms and optionally substituted by one to three independently selected halogen atoms; and Y? is alkyl or alkenyl, each of which is branched or unbranched and contains 1-5 carbon atoms optionally interrupted by one heteroatom selected from O, S and N and optionally substituted by one to three independently selected halogen atoms.

Even more preferably R? is SiMe, SiMe;Et, SiMe,CHMe;,, SiMe,CH,CHMe;,

SiMe,CH,CMe;, SiMe,OCHMe,, SiMe, OCH,CHMe;, CH,SiMe;, CH,SiMe;Et,

CH,SiMe,CHMe,, CH,SiMe,CH,CHMe;, CH2SiMe;OMe, CH,SiMe,OCHMe;,

CH,SiMe;0CH,CHMe,, CHMeSiMe;, CHMeSiMe, OMe, (CH,),SiMes, (CH2).SiMe;Et, (CH,);SiMe;CHMe,, (CH;),SiMe,CMes, (CH,).SiMe,CH,CHMe;, (CH,),SiMe,CH,CH; Me, (CH,),SiMe,CH,CMes, (CH2),SiMe,OCHMe;, (CHz),SiMe,OCH,CHMe,, CHMeCH,SiMes,

CHMeCH,SiMe,Et, CHMeCH,SiMe,CH,CH,Me, CHMeCH,SiMe,CHMe;,

CHMeCH;SiMe; CMe, CHMeCH;SiMe;CH;CHMe,, CFMeCH;SiMes,

CHMeCH,CH,SiMe,OMe, CHMeCH,SiMe,OCHMe,, CHMeCH,SiMe,OCH,CHMe,, :

CH,CHMeSiMe;, CH,CHMeSiMe Et, CH,CHMeSiMe,CHMe,, CHMeCHMeSiMes,

CMe, CH,SiMe;, (CH;);SiMes, (CH,);SiMe, Et, (CH2):SiMe,CHMe,, (CH,):SiMe,CH,CHMe,, (CH;);SiMe, OMe, (CH>);SiMeOCHMe,, (CH,);SiMe,OCH,CHMe,, CHMeCH,CH,SiMe;, CHMeCH,CH,SiMe;Et, CHMeCH,CH,SiMe;CHMe,, CHMeCH;CH,CH;SiMe;0Me, 20° CHMeCH,CH,SiMe,OCHMe;, CMe=CHSiMe3; or CH.CH,SiMe;OMe.

Most preferably R? is SiMe;, SiMe;Bt, SiMe,CHMe;, SiMe,CH,CHMe;,

SiMe,CH,CMes, (CH,),SiMes, (CH2).SiMe Et, (CH2),SiMe,CHMe,, (CH;)2SiMe, CMe, (CH2):SiMe,CH,CHMe;, CHMeCH,SiMe;, CHMeCH,SiMe, Et, CH,CHMeSiMe;,

CMe,CH,SiMe; or (CH;):SiMe;.

Nitrogen atoms in the Het ring are, independently, either unsubstituted or substituted by

R®. When R* is a substituent on a nitrogen atom it is preferably C;.; alkyl, C13 haloalkyl or methoxymethylene; more preferably C,.; alkyl, CF3;, CF2Cl, CHF;, CHF or ‘methoxymethylene; even more preferably methyl, CHF; or methoxymethylene; yet more preferably methyl or methoxymethylene; and most preferably methyl.

Carbon atoms in the Het ring which are not bonded to the atom substituted by CXNR! are, independently, either unsubstituted or substituted by R*. When R*is a substituent on a carbon atom which is not bonded to the atom substituted by CXNR! it is preferably halogen,

C3 alkyl, C,.; haloalkyl or methoxymethylene; more preferably chloro, methoxymethylene,

CHs, CHF, or CF3; yet more preferably chloro, CH3, CHF; or CFs; and even more preferably

CH; or CFs. }

There may be one or two carbon atoms in the Het ring bonded to the atom substituted by

CXNR'; such carbon atoms are, independently, either unsubstituted or substituted by RY.

When R* is a substituent on a carbon atom bonded to the atom substituted by CXNR' it is preferably halogen, C,.3 alkyl or C3 haloalkyl; more preferably chloro, fluoro, bromo,

Ci. alkyl, CF, CF,Cl, CHF; or CHF; and even more preferably chloro, fluoro, bromo, methyl, CF;, CHF; or CHoF. :

More preferably, when there is only one carbon atom in the Het ring bonded to the atom substituted by CXNR! that carbon atom is substituted by R*.

More preferably, when there are two carbon atoms in the Het ring bonded to the atom substituted by CXNR' one such carbon atom is substituted by R* and the other carbon atom is either unsubstituted or is substituted by fluoro, chloro or methyl. : Most preferably the combination of Het, R* and CXNR! is -Me-3-R*-4-CXNR! pyrazolyl, 1-Me-3-R*-4-CXNR! pyrrolyl, 2-Me-3-R*-4-CXNR thiazolyl or 2-R*-3-CXNR! pyridinyl.

Preferably X is oxygen. | Preferably ris 0.

When a compound of formula (I) is an N-oxide then it is preferred that Het is pyridinyl substituted by one to three groups RY :

Throughout this description, Me is used to represent the methyl group. Likewise, Et "represents the ethyl group.

Thiophenes of formulae (IIa) and (IIb)

Rr®

S S

Oa Oa.

R® A (lla) (lib)

where R? is as defined above and A is NH, NHCH(Q), optionally substituted (C14)alkylC(=0)NH, optionally substituted (Ci.4)alkylOC(=O)NH, halogen or N=C(CsHs), are useful as intermediates in the preparation of compounds of formula (I).

Compounds of formulae (IIa) and (IIb) where R3 is SiMe, Et, SiMe,CHMEe,,

SiMe, CH,CHMe, SiMe,CH,CMes, CH=CHSiMes, (CHz),SiMes, (CH,)SiMe,Et, (CH,),SiMe,CHMe,, (CH,),SiMe;CMe;, (CHa),SiMe,CH,CHMe;, CHMeCH,SiMes,

CHMeCH,SiMe, Et, CH,CHMeSiMes, CMe,CH,SiMes or (CH,)3SiMes; and A is as defined above [provided that A is not halogen when R? is SiMes] are novel and are preferred as intermediates for the preparation of compounds of formula (I). Compounds of formulae (IIa) and (IIb) where R® is SiMe; and A is halogen are already known.

Therefore, in another aspect the present invention provides a compound of formula (Ia) or (IIb) where R? is SiMe, SiMe, Ft, SiMe,CHMe,, SiMe,CH,CHMe,, SiMe,CH,CMe;,

CH=CHSiMe;, (CH,),SiMe,, (CH,)SiMe,Et, (CH,),SiMe,CHMe;, (CH2),SiMe,CMe;, (CH,),SiMe,CH,CHMe,, CHMeCH,SiMe;, CHMeCH,SiMe;Et, CH,CHMeSiMe;, : ' CMe, CH,SiMe;, (CH,);SiMes; and A is NH,, NHCH(O), optionally substituted (C1.4)alkylC(=O)NH, optionally substituted (C;.4)alkylOC(=O)NH, halogen or N=C(C¢Hs),; provided that A is not halogen when R’ is SiMes. ~The compounds of formula (I), (Ila) and (IIb) may exist as different geometric or optical isomers or in different tautomeric forms. This invention covers all such isomers and tautomers and mixtures thereof in all proportions as well as isotopic forms such as deuterated compounds.

The compounds in Tables 1 to 28 below illustrate particularly preferred compounds of : - the invention, in which rR’, R® and R” are each, independently, examples of R* as defined above. :

Table A represents Table 1 (when A is 1), represents Table 2 (when A is 2), represents

Table 3 (when A is 3) and represents Table 4 (when A is 4).

Table A

Compound R |X ics Il EE od ll el

FE NO 0 BoB

PS Bn 1

BEER IL a A

PC BL cil roe | We [wo

BC a mew [ww Jowo owe | we [wo [oe we [oo

EE ee a rE | mee | Fw [wo ome [we wo]

IE I 1 fre] nse [ww | @ Jo

IEE LC BL mse [wjmos| wo me | [eo a fo ar meme] Ww [0 ore [oo @ [o arama] [oo [per cmecne [WW [w [0 i wer | meme | [0

CC 7-

I I IE NL zal

A | det | Gwe, | A | We | oon [0

I ce Bl BL a [cow | owe | # | We | 06 [0

IE I CN BL Nd

IEC I NL BL Ba Rea

EE A Ro I a el

I eC BL I eR

EE Gc CR BL

I A LC LR OR a a a I BL

W | Cromsteone | | We | G5 [0 wo [EO ometeow |W | We | oo,

I A eo BL

I ccc HL BL a [Am [| avemws |W] We | oo]

CC A CR BL BL A

I cL NE cl

IEC cL NL cl

I cL WL 3 cM we | E| owen |W | we [GD

I CO NE NL 3

IC cc I NL 1

IRS a cc CN IE NE 1 wm [TE | oem |W | We | oo wm [TE | chow [WW [mo]

I sc a BL 1

I I co LC 2

I a a Re as] H| Ouseercme A] we [owo a Ra

Rw |W | omecnsomods | A | We | G60 [RE R| ceommses | | ¥e | on [0]

EC sai I KN

I Eo a

Ra |W | ems | ® | We | oh [0

Re |W | Cmseome |W |W [G0]

I I ccc FL BR

I Cc ere LN He a

IE I Nc I a ead

IC co BL Na KN

CC I CH Wa KN

BO cc NL Ba cal

I cc a Kil

I A cc Bm eR

ES I ces a EO ea

IE Ci) CO I NL ed

I I I CC I a eid

I I TT HL a He

IE I I LB al

IE 2 Nl BN Ka wo

Er eee teres

EE |W Gwewe [A Ww [wo “AS TW | cows [#]w [@ 0

EE cc CR BL LC a

I Mc I CO IE NL Kec

Rw [oo [weve [A] Ww [0

Table 1 provides 86 compounds of formula (Ia) where R!, R3 R’, R®, R’ and X are as defined in Table 1. s { [

R' ’ o 3 i” (ta) 8

Table 2 provides 86 compounds of formula (Ib) where R! RR’, R® R’ and X are as defined in Table 2. oo RA_S bE,

Bee

RI

7 \ (Ib)

Nan R® . } k

Table 3 provides 86 compounds of formula (Ic) where R', R® R R® R’ and X are as defined in Table 3.

S

{ ]

Rr’ / \

N R® (ic)

RS

Table 4 provides 86 compounds of formula (Id) where R', R®, R%, R, R” and X are as defined in Table 4. . RS hE;

A

R! : / \

Id

N R® (1d)

R’

Table B represents Table 5 (when B is 5), represents Table 6 (when B is 6), represents

Table 7 (when B is 7) and represents Table 8 (when B is 8).

Table B

Compound X

EES a A

IEE NC I We Gl

I NC BL Ke a

ILE I IL eR

I I ad I me [poe] Ge [We |G] 0

I CC 0

SS I a NE 2d Hl ss [| awe | wos [5

SO Cc) LC

Ear | omen | | 6 | 0 [em few [ewe | we [a [0 [En | owes | we | eo]

I IC NL EN EL

I

EU [row] Qeve | we | © | 0]

Ew | & | @mewe | we | We [0

Ev |W | @wewe | [es] 0

I LA eC LN I

I A eC NL EU

I CL EN

I Ce Mc LL ad I

EE NL eC NT Ms

LE a cic RL Ne

I LC Hc

IE CE cll

EE I LB

EE A a EL I

IEE A ey BL EN

LL ey a ea

Ew | | comes | We | @ | 0

I eo NL el I

Ey |W | oweoisie | We | | 0

EW | | owecmswe | We [Go| 0]

EE oY NL Kr

I I oY LC ma |W | cowesws | We | Ob | 0

Ee |W | croweswe | We |G | 0

Eo | Ecce | We | oo | 0 ew |W [mechan | We | | 0

I IC Cc ec

I I a I sw | | sweencmin |we | o6 | 0

Table 5 provides 47 compounds of formula (Ie) where R', R? R® RS and X are as defined in Table 5.

S

2 "yo : te)

RS

Table 6 provides 47 compounds of formula (If) where R',R3 RR’, Réand X are as defined in Table 6. . RY S 0

RY N

=( RW 0

NaS

JS

Table 7 provides 47 compounds of formula (Ig) where R!,R? RS’, R® and X are as defined in Table 7.

S

«84 - a N rR? a :

NP )

R®

Table 8 provides 47 compounds of formula (Ih) where R', R®, R’, RS and X are as defined in Table 8. : : od o

NY

_

R (th)

NO

RS

Table BB represents Table 9 (when BB is 9) and represents Table 10 (when BB is 10).

Table BB

Compound X

No.

Cre

Css

CECH

Table 9 provides 5 compounds of formula (Ii) where R',R? R® RC and X are as defined in Table 9. pI 7 R (iy

No ls

R

Table 10 provides 5 compounds of formula (Ij) where R', R®, R, R and X are as defined in Table 10. “

Ai 7 NR (1)

No ls

R

Table C represents Table 11 (when C is 11), represents Table 12 (when Cis 12), represents Table 13 (when C is 13) and represents Table 14 (when C is 14).

Table C

Compound rR! R’ X nhl

FC OL WC Lc BL

BCC EL NLC LC EL

EC TC a SON EL

IEC BC RC LC BN

EC a RON EL

Bm A

CC RC LCN CS

[ow | emi | | We [0

CII I on oo | omen |W | We | We [0

CE LR a I

CL Lh a EN os [wae [ww [0

EE SL EN

IL 3 BL EA

I I 8 BL a

EE a Ba

PC I Re NL a

EE 0) a a EL

I 8 RL a A row | CaS | | We | Fo

EE) a or | coms, | ve | we | 0° a I a NL cme |B |W] [0

Crm 0s CN a a che | We | We | BO

Table 11 provides 35 compounds of formula (Ik) where R', R3 R> RS R’ and X are as defined in Table 11. :

S oo \

RY N Rr? 1 (1k) 4. R

R® Ng” R

Table 12 provides 35 compounds of formula (II) where R!, R3 R5, R® R’ and X are as defined in Table 12.

RLS

0

RY N

1 (mn

TR

. R® Ss R

Table 13 provides 35 compounds of formula (Im) where RR? R% R® R’ and X are as defined in Table 13. 3 \ 4 3 rR No” TR

Table 14 provides 35 compounds of formula (In) where R, RR’, R® R’ and X are as defined in Table 14. “~O \W/

RY N

R' (In) : = o R® :

Table D represents Table 15 (when D is 15), represents Table 16 (when D is 16), represents Table 17 (when D is 17) and represents Table 18 (when D is 18).

Table D

Comte |W ®[® [X

IE CN NL

IE NL I i os [Tw | ome wo os | cow | ome | we | 0]

I a RN CR

IA NL CO LN NC

IE EE CNN

I BL CN NN

D0 | pow | cies | We | 0

I NC eR on | Cow | ame |W | 0

I a CR ENC

I RL Ca EN

I BL 2

Tow | Gps | We | 0]

ow [cow | se [we [0] om |W | consi | We | 0]

EE I CR RR

ELE aN eC

EE Rr eC TG

CE

OF [pe | Gone | C6 | 0 ow | we | Geom | oh | 0] ow [cow | cose | 6 | 0 om [ae | amen | Ne | 0

EL CR EN

I I on ER [To [names [We [0] ow [ow | owas | 06 [0

Table 15 provides 32 compounds of formula (Io) where R!, R3, R® and X are as defined in Table 15.

S

2 : J

Table 16 provides 32 compounds of formula (Ip) where R', R? R® and X are as defined in Table 16.

BY, \

N (Ip) \_—

Oo

Table 17 provides 32 compounds of formula (Iq) where R, R® , R® and X are as defined in Table 17.

Ss \

NF we

S 1 q

R

Che 0°

Table 18 provides 32 compounds of formula (Ir) where R!, R’, R’ and X are as defined in Table 18.

N

S R (Ir) ad | O

Table E represents Table 19 (when E is 19), represents Table 20 (when E is 20), represents Table 21 (when E is 21), represents Table 22 (when E is 22), represents Table 23 (when E is 23) and represents Table 24 (when E is 24).

Table E

I I CB

IC I BN 50

I I BN RN

CI NE

[EF [ewes Jeo

I I BN

IE Ca BR

En | dew | cmews | a [0

Em | ow | mews | a [0

IE 2 BN

I 2. Ba

I NL 2 [ET [ee | cme @ 0]

I Nc eB

ES |W | omc | G0

TE |W | meee | m0

Em |W | omens [O50

ED | pean | Omiecasie |G | 0

Ew [aw | cece | 0] 0 em | cow | omens | 6 | 0]

Ew | pew | cscs |B 0 [ET [en | cme | BO [EE | cow | omc | m0

Es commow| cacy | a | 0

Ew [como | cawcmsae | Gb | 0

I LC BL

I LN GC BL

I NO I HN

Ew [ow | creme | Gh | 0

Es |W [ ceomeen | a [0]

EE a er |W | swomwe [oO]

—ev wesw [ao swe | 0 svete | 5 | 0

EC svete | 0 svc | | 0 swe | A 0

N R® \, (1s) =N

Table 20 provides 45 compounds of formula (It) where R!, R? R® and X are as defined in Table 20.

RA_S 0

N

= (t) =N

Table 21 provides 45 compounds of formula (fu) where R', R*, R® and X are as defined in Table 21.

S

\ ]

Kk ~ S&C (10)

NL Nps —N

Table 22 provides 45 compounds of formula (Iv) where R!, R?, R® and X are as defined in Table 22.

RI: .S 0

N 1 (Iv) v/4 \ R

N Rr yg

Table 23 provides 45 compounds of formula (Iw) where RY, R3, R® and X are as defined in Table 23. : Ss x \ ]

SE

J N (lw)

N_-

N=N

Table 24 provides 45 compounds of formula (Ix) where R', R?, R® and X are as defined in Table 24.

BY,

N

M1 (Ix) 7 R ~

N=N

Table 25 provides 10 compounds of formula (Iy) where R’ and (R?), are as defined in

Table 25. : 7

R Oo 2-§ [ys

NNT

N H

Me SiMe, (ly)

Table 25

EE Rc —s wo — mw ew 25.10 2-C1,5-Cl

Table 26 provides 10 compounds of formula (Iz) where R’ and (R?), are as defined in

Table 26.

Me,Si 7

R 0 S 20, yy TE a

Me (12)

Table 26

IC a mo |]

A TE

I CL A

EL WL NA

I

Table G represents Table 27 (when Gis 27) and represents Table 28 (when G is 28).

Table G

Compound A

EI

I I I BN

I EN NCL

CEI Ds bs ci)

I DCRR A

I Mc 08

I DN hice

CA I CN or owes | ww

I Ie. INA

Es hs om we | woo

Eo ca

Claims

1. A compound of formula (I) 2 —S 2 : Het “Rr? R! where Het is a 5- or 6-membered heterocyclic ring containing one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, the ring being substituted by one to three groups R*; R' is hydrogen, optionally substituted (Ci4)alkyl, formyl, optionally substituted (C;.4)alkylC(=0), optionally substituted (C19)alkylC(=0)O, optionally substituted (Ci4)alkoxy(Ci4)alkyl, optionally substituted allyl, optionally substituted propargyl or optionally substituted allenyl; each R?is, : independently, halogen, optionally substituted (Ci4)alkyl, optionally substituted (C,4)alkoxy or optionally substituted (Cy-q)alkoxy(Cis)alkyl; R3 is either at position 2 or at position 4 of the thiophene ring and is an organic group containing three to thirteen carbon atoms and at least one silicon atom and, optionally, one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, and is optionally substituted by one to four independently selected halogen atoms; each R%is, independently, halogen, C3 alkyl, Ci.3 haloalkyl, C1.salkoxy(C.3)alkyl Or cyano; r is 0, lor2; and XisOorS;oran N-oxide thereof.

3. A compound of formula (I) as defined in claim 1 or 2 where R! is hydrogen, propargyl, allenyl, formyl, CH:C(=O), C,H5C(=0) or CH;OCH,C(=0).

4, A compound of formula (I) as defined in claim 1, 2 or 3 where each R? is independently selected from halogen, methyl, trifluoromethyl and trifluoromethoxy.

5. A compound of formula (I) as defined in claim 1, 2, 3 or 4 where Het is pyrazolyl, pyrrolyl, thiophenyl, furyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, _ pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, 5.6-dihydropyranyl or 5.6-dihydro-1.4- : oxathiinyl each being substituted by one to three groups RY.

6. A compound of formula (I) as defined in claim 1, 2, 3, 4 or 5 where R? is an aliphatic, saturated or unsaturated group containing three to thirteen carbon atoms and at least one silicon atom and, optionally, one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, and is optionally substituted by one to four independently selected halogen atoms.

7. A compound of formula (I) as defined in'claim 1,2, 3, 4, 5 or 6 where X is oxygen.

8. A compound of formula (IIa) or (IIb) . RS 5 S S \ a OU. R® A : (ha) (1b) where R® is SiMe, Et, SiMe,CHMe;,, SiMe,CH,CHMex, SiMe, CH,CMes, CH=CHSiMe;, (CHa),SiMe3, (CH,)2SiMe;Et, (CH,),SiMe,CHMe,, (CH;)2S1Me CMe, (CH,),SiMe,CH,CHMe,, CHMeCH,SiMe;, CHMeCH,SiMe, Et, CH,CHMeSiMes, CMe,CH,SiMes, (CH,)3SiMe;; and A is NHz, NHCH(O), optionally substituted (C1-4)alkylC(=0)NH, optionally substituted (C).4)alkylOC(=O)NH, halogen or N=C(CeHs)2; provided that A is not halogen when R3 is SiMe;.

9. A composition for controlling microorganisms and preventing attack and infestation of plants therewith, wherein the active ingredient is a compound of formula (I) as claimed in claim 1 together with a suitable carrier.

10. A method of controlling or preventing infestation of cultivated plants by phytopathogenic microorganisms by application of a compound of formula (I) as claimed in claim 1 or a composition as claimed in claim 9 to plants, to parts thereof or the locus thereof.