-102-A method of combating and controlling insects, acarines, nematodes or molluscs which comprises applying to a pest, to a locus of a pest, or to a plant susceptible to attack by a pest an insecticidally, acaricidally, nematicidally or molluscicidally effective amount of a compound of formula I.

Y is a single bond, C=O, C=S or S(O)m where m is 0, 1 or 2;
the ring is a 6 membered aromatic ring or is a 5 or 6 membered heteroaromatic ring;

R1 is hydrogen, optionally substituted alkyl, optionally substituted alkoxycarbonyl, optionally substituted alkylcarbonyl, aminocarbonyl, optionally substituted alkylaminocarbonyl, optionally substituted dialkylaminocarbonyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted heterocyclyloxy, cyano, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, formyl, optionally substituted heterocyclyl, optionally substituted alkylthio, NO or NR13R14 where R13 and R14 are independently hydrogen, COR15, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl or R13 and R14 together with the N atom to which they are attached form a group -N=C(R16)-NR17R18 or R13 and R14 together with the N atom to which they are attached form a five, six or seven-membered heterocyclic ring which may contain one or two further heteroatoms selected from O, N or S and which may be optionally substituted by one or two C1-6 alkyl groups; R15 is H, optionally substituted alkyl, optionally substituted alkoxy, optionally substituted aryl, optionally substituted aryloxy optionally substituted heteroaryl, optionally substituted heteroaryloxy or NR19R20; R16, R17 and R18 are each independently H or lower alkyl; R19 and R20 are independently optionally substituted alkyl, optionally substituted aryl or optionally substituted heteroaryl;

R2 is H or optionally substituted alkyl; or R1 and R2 togethere with the groups Y and N form a 5-or 6-membered heterocyclic ring which may optionally contain one further heteroatom selected from 0, N or S and which may be optionally substituted by C1-4 alkyl, C1-4 haloalkyl or halogen;
each R4 is independently halogen, nitro, cyano, optionally substituted C1-8 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted alkoxycarbonyl, optionally substituted alkylcarbonyl, optionally substituted alkylaminocarbonyl, optionally substituted dialkylaminocarbonyl, optionally substituted C3-7 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted alkylthio or R21R22N where R21 and R22 are, independently, hydrogen, C1-8 alkyl, C3-7 cycloalkyl, C3-6 alkenyl, C3-6 alkynyl, C3-7 cycloalkyl(C1-4)alkyl, C2-6 haloalkyl, C1-6 alkoxy(C1-6)alkyl, C1-6 alkoxycarbonyl or R21 and R22 together with the N atom to which they are attached form a five, six or seven-membered heterocyclic ring which may contain one or two further heteroatoms selected from 0, N or S and which may be optionally substituted by one or two alkyl groups, or 2 adjacent groups R4 together with the carbon atoms to which they are attached form a 4, 5, 6,or 7 membered carbocyclic or heterocyclic ring which may be optionally substituted by halogen; n is 0, 1, 2, 3 or 4;

R8 is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted alkoxycarbonyl, optionally substituted alkylcarbonyl or optionally substituted alkenylcarbonyl;

each Ra is independently halogen, hydroxy, cyano, optionally substituted C1-8 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted alkoxycarbonyl, optionally substituted alkylcarbonyl, optionally substituted alkylaminocarbonyl, optionally substituted dialkylaminocarbonyl, optionally substituted C3-7 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted alkylthio, optionally substituted arylthio or R23R24N
where R23 and R24 are, independently, hydrogen, C1-8 alkyl, C3-7 cycloalkyl, C3-6 alkenyl, C3-6 alkynyl, C3-7 cycloalkyl(C1-4)alkyl, C2-6 haloalkyl, C1-6 alkoxy(C1-6)alkyl, alkoxycarbonyl or R23 and R24 together with the N atom to which they are attached form a five, six or seven-membered heterocyclic ring which may contain one or two further heteroatoms selected from 0, N or S and which may be optionally substituted by one or two C1-6 alkyl groups, or two Ra groups attached to the same carbon atom are =O, =S, =NRb, =CRcRd where Rb, Rc and Rd are idependently H or optionally substituted alkyl; p is 0, 1, 2, 3 or 4 or salts or N-oxides thereof.

2. A method according to claim 1 wherein the ring is a 6-membered aromatic ring or is 5 or 6 membered heteroaromatic ring wherein the ring members are each independently CH, S, N, NR4, O, or CR4 provided that at least one ring member is other than CH or CR4 and that there are no more than one O
or S
atoms present in the ring.

3. A method according to claim 1 or claim 2 wherein Y is a single bond, C=O or C=S.

4. A method according to any preceding claim wherein R1 is hydrogen, C1-6 alkyl, C1-6 cyanoalkyl, C1-6 haloalkyl, C3-7 cycloalkyl(C1-4)alkyl, C1-6 alkoxy(C1-6)alkyl, heteroaryl(C1-6)alkyl (wherein the heteroaryl group may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, alkylsulfonyl, C1-6 alkylsulfinyl, C1-6 alkylthio, C1-6 alkoxycarbonyl, C1-6 alkylcarbonylamino, arylcarbonyl, or two adjacent positions on the heteroaryl system may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen), aryl(C1-6)alkyl (wherein the aryl group may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, C1-6 alkylsulfonyl, C1-6 alkylsulfinyl, C1-6 alkylthio, C1-6 alkoxycarbonyl, C1-6 alkylcarbonylamino, arylcarbonyl, or two adjacent positions on the aryl system may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen), C1-6 alkylcarbonylamino(C1-6)alkyl, aryl (which may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, C1-6 alkylsulfonyl, C1-6 alkylsulfinyl, C1-6 alkylthio, C1-6 alkoxycarbonyl, C1-6 alkylcarbonylamino, arylcarbonyl, or two adjacent positions on the aryl system may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen), heteroaryl (which may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, C1-6 alkylsulfonyl, C1-6 alkylsulfinyl, C1-6 alkylthio, C1-6 alkoxycarbonyl, C1-6 alkylcarbonylamino, arylcarbonyl, or two adjacent positions on the heteroaryl system may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen), C1-6 alkoxy, C1-6 haloalkoxy, phenoxy (wherein the phenyl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), heteroaryloxy (optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), heterocyclyloxy (optionally substituted by halo, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), cyano, C2-6 alkenyl, alkynyl, C3-6 cycloalkyl, C5-7 cycloalkenyl, heterocyclyl (optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), C1-6 alkylthio, C1-6 haloalkylthio or NR13R14 where R13 and R14 are independently hydrogen, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy(C1-6)alkyl, phenyl (which may be optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-haloalkoxy, CN, NO2, aryl, heteroaryl, amino, dialkylamino or C1-4 alkoxycarbonyl), phenyl (C1-6)alkyl (wherein the phenyl group may be optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino, dialkylamino, C1-6 alkylsulfonyl, C1-6 alkoxycarbonyl, or two adjacent positions on the phenyl ring may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen), heteroaryl (C1-6)alkyl (wherein the heteroaryl group may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, C1-6 alkylsulfonyl, C1-6 alkylsulfinyl, C1-6 alkylthio, C1-6 alkoxycarbonyl, C1-6 alkylcarbonylamino, arylcarbonyl, or two adjacent positions on the heteroaryl system may be cyclised to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring, itself optionally substituted with halogen) or heteroaryl (which may be optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy, C1-4 alkoxycarbonyl C1-6 alkylcarbonylamino, phenyloxycarbonylamino (wherein the phenyl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), amino, C1-6 alkylamino or phenylamino (wherein the phenyl group is optionally substituted halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino)).

5. A method according to any preceding claim wherein R2 is hydrogen, hydroxy, alkyl or C1-6 haloalkyl.

6. A method according to any preceding claim wherein each R4 is independently halogen, cyano, C1-8 alkyl, C1-8 haloalkyl, C1-6 cyanoalkyl, C1-6 alkoxy(C1-6)alkyl, C3-7 cycloalkyl(C1-6)alkyl, C5-6 cycloalkenyl(C1-6)alkyl, C3-6 alkenyloxy(C1-6)alkyl, C3-6 alkynyloxy(C1-6)alkyl, aryloxy(C1-6)alkyl, C1-6 carboxyalkyl, C1-6 alkylcarbonyl(C1-6)alkyl, C2-6 alkenylcarbonyl(C1-6)alkyl, C2-6 alkynylcarbonyl(C1-6)-alkyl, C1-alkoxycarbonyl(C1-6)alkyl, C3-6 alkenyloxycarbonyl(C1-6)alkyl, C3-6 alkynyloxycarbonyl(C1-6)alkyl, aryloxycarbonyl(C1-6)alkyl, C1-6 alkylthio(C1-6)alkyl, C1-6 alkylsulfinyl(C1-6)alkyl, C1-6 alkylsulfonyl(C1-6)alkyl, aminocarbonyl(C1-6)alkyl, C1-6 alkylaminocarbonyl(C1-6)alkyl, di(C1-6)alkylaminocarbonyl(C1-6)alkyl, phenyl(C1-4)alkyl (wherein the phenyl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), heteroaryl(C1-4)alkyl (wherein the heteroaryl group is optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or haloalkoxy), heterocyclyl(C1-4)alkyl (wherein the heterocyclyl group is optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or haloalkoxy), C2-6 alkenyl, aminocarbonyl(C2-6)alkenyl, C1-6 alkylaminocarbonyl(C2-6)alkenyl, di(C1-6)alkylaminocarbonyl(C2-6)alkenyl, phenyl(C2-4)-alkenyl, (wherein the phenyl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), alkynyl, trimethylsilyl(C2-6)alkynyl, aminocarbonyl(C2-6)alkynyl, C1-6 alkylaminocarbonyl(C2-6)alkynyl, di(C1-6)alkylaminocarbonyl(C2-6)alkynyl, C1-6 alkoxycarbonyl, C3-7 cycloalkyl, C3-7 halocycloalkyl, C3-7 cyanocycloalkyl, C1-alkyl(C3-7)-cycloalkyl, C1-3 alkyl(C3-7)halocycloalkyl,phenyl (optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), heteroaryl (optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), heterocyclyl (wherein the heterocyclyl group is optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), or 2 adjacent groups R4 together with the carbon atoms to which they are attached form a 4, 5, 6 or 7 membered carbocylic or heterocyclic ring which may be optionally substituted by halogen, C1-8 alkoxy, C1-6 haloalkoxy, phenoxy (optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy), heteroaryloxy (optionally substituted by halo, nitro, cyano, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or haloalkoxy), C1-8 alkylthio or R19R20N where R19 and R20 are, independently, hydrogen, C1-8 alkyl, C3-7cycloalkyl, C3-6 alkenyl, C3-6 alkynyl, C2-6 haloalkyl, C1-6 alkoxycarbonyl or R19 and R20 together with the N atom to which they are attached form a five, six or seven-membered heterocyclic ring which may contain one or two further heteroatoms selected from 0, N or S and which may be optionally substituted by one or two C1-6 alkyl groups; n is 0, 1, 2 or 3.

7. A method according to any preceding claim wherein R8 is C1-10 alkyl, C1-10 haloalkyl, aryl(C1-6)alkyl (wherein the aryl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C14 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), heteroaryl(C1-6)alkyl (wherein the heteroaryl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), arylcarbonyl-(C1-6)alkyl (wherein the aryl group may be optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino and the alkyl group may be optionally substituted by aryl), C2-8 alkenyl, C2-8 haloalkenyl, aryl(C2-6)-alkenyl (wherein the aryl group is optionally substituted halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino, C1-6 alkoxycarbonyl, or two adjacent substituents can cyclise to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring), heteroaryl(C2-6)-alkenyl (wherein the heteroaryl group is optionally substituted halogen, C14 alkyl, C1-alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino, C1-6 alkoxycarbonyl, or two adjacent substituents can cyclise to form a 5, 6 or 7 membered carbocyclic or heterocyclic ring), C2-6 alkynyl, phenyl(C2-6)alkynyl (wherein the phenyl group is optionally substituted by halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), C3-7 cycloalkyl, C1-6 alkoxycarbonyl, C1-6 alkylcarbonyl, C1-6 haloalkylcarbonyl or aryl(C2-6)alkenylcarbonyl (wherein the aryl group may be optionally substituted halogen, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl, C1-4 haloalkoxy, CN, NO2, aryl, heteroaryl, amino or dialkylamino), or -C(R51)(R52)-[CR53=CR 54]z-R55 where z is 1 or 2, R51 and R52 are each independently H, halo or C1-2 alkyl, R53 and R54 are each independently H, halogen, C1-4 alkyl or C1-4 haloalkyl and R55 is optionally substituted aryl or optionally substituted heteroaryl.

8. A method according to any preceding claim wherein Ra is independently halo, cyano, C1-3 alkyl, hydroxy or two Ra groups together with the carbon atom to which they are attached form =O, =S, =NRb, =CRcRd where Rb, Rc and Rd are idependently H or optionally substituted alkyl, and p is 0, 1 or 2.

10. A compound of formula wherein R4, R8, Ra, T, Y, n and p are as defined'in relation to formula I' in claim 9 provided the compound is other than 4,5-diamino-6-(4-cinnamyl-l-piperazinyl)-pyrimidine.

11. A compound of formula wherein R4, R8, Ra, T, Y, n and p are as defined in relation to formula I' in claim 9 provided that when T is a phenyl ring, R8 is cinnamyl and p is 0 then R4 is not a CF3 or NO2 group para to the piperazine ring and further provided the compound is other than 4-amino-6-(4-cinnamyl-1-piperazinyl)-5-nitro-pyrimidine.

12. An insecticidal, acaricidal or nematicidal composition comprising an insecticidally, acaricidally or nematicidally effective amount of a compound of formula I as defined in claim 1.