Herbicidal Pyridino-/Pyrimidino-Thiazoles

A method of selectively controlling weeds at a locus comprising crop plants and weeds, wherein the method comprises application to the locus, of a weed-controlling amount of (i) a compound of formula (I):

• or a salt or N-oxide thereof, wherein,
• X1 is N or CR1;
• R1 is hydrogen, halogen, cyano, C1-C6alkyl, C3-C6cycloalkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6alkoxy, —C(O)OR6 or S(O)n(C1-C6alkyl), formyl, hydroxyl, —C(O)NR6R7, NR6R7, benzyloxy, C1-C6 haloalkoxy, or C1-C6 haloalkyl;
• R2 is hydrogen, halogen, cyano, nitro, C1-C6 alkyl, C1-C6haloalkyl, C2-C6alkenyl, C2-C6 alkynyl, C3-C6cycloalkyl, —C(O)OR6, S(O)n(C1-C6alkyl), C1-C6 alkoxy, or C1-C6 haloalkoxy;
• n is 0, 1, or 2;
• R3 is hydrogen, cyano, C1-C6alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C2-C6haloalkenyl, C1-C6 alkoxy, C1-C6 haloalkyl, C1-C6haloalkoxy, C2-C6alkenyloxy, C3-C10cycloalkyl, NR6R7,
• R4 is O, S, or N(C1-C6alkyl);
• X2 is O, S, or NR8;
• R5 is hydrogen, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C3-C10cycloalkyl, C3-C10cycloalkenyl, C1-C6haloalkyl, C2-C6haloalkenyl, C1-C6alkoxy, C1-C6haloalkoxy, C2-C6alkenyloxy, C2-C6alkynyloxy, C3-C10cycloalkyloxy, C3-C10cycloalkenyloxy, C2-C6haloalkenyloxy, C6-C10aryl or C6-C10aryl substituted by from 1 to 3 groups independently selected from halogen, nitro, cyano, C1-C3 alkyl, C1-C3 alkoxy, C1-C3 haloalkyl, and C1-C3 haloalkoxy;
• C3-C10heterocylcyl or C3-C10heterocyclycl substituted by from 1 to 3 groups independently selected from halogen, nitro, cyano, C1-C3 alkyl, C1-C3 alkoxy, C1-C3 haloalkyl, and C1-C3 haloalkoxy;
• or NR6R7;
• or R3 and R5 together with X2 and the atoms to which they are attached, form a saturated or partially unsaturated 5-9 membered ring system optionally comprising 1 to 3 heteroatoms independently selected from S, O and N and optionally substituted with 1 to 3 groups independently selected from halogen or C1-C6 alkyl;
• or R3 and R8 together with the atoms to which they are attached form a saturated or partially unsaturated 5-9 membered ring system optionally comprising 1 to 3 heteroatoms independently selected from S, O and N and optionally substituted with 1 to 3 groups independently selected from halogen or C1-C6 alkyl;
• R6 and R7 are each independently hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, or C2-C6 alkynyl,
• or R4 and R5 together with X2 and the atoms to which they are attached, form a saturated or partially unsaturated 5-9 membered ring system optionally comprising 1 to 3 heteroatoms independently selected from S, O and N and optionally substituted with 1 to 3 groups independently selected from halogen or C1-C6 alkyl;
• or R6 and R7 together with the nitrogen atom to which they are attached form a saturated or partially unsaturated 3-6 membered ring optionally comprising 1 to 3 heteroatoms independently selected from S, O and N and optionally substituted with 1 to 3 groups independently selected from halogen or C1-C6 alkyl;
• R8 is hydrogen, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, or C2-C6 alkynyl;
• C1-C6alkoxy, C1-C6haloalkoxy, C2-C6alkenyloxy, C2-C6alkynyloxy, C3-C10cycloalkyloxy, C3-C10cycloalkenyloxy, C2-C6haloalkenyloxy;
• or R7 and R8 together with the carbon atoms to which they are attached form a saturated or partially unsaturated 3-9 membered ring optionally comprising 1 to 3 heteroatoms independently selected from S, O and N and optionally substituted with 1 to 3 groups independently selected from halogen or C1-C6 alkyl.