Pyrazole derivatives as herbicides

A compound of formula I

• wherein
• R1 is hydrogen, C1-C4alkyl, C1-C4haloalkyl, cyano-C1-C4alkyl, C3- or C4-alkenyl, C3- or C4-haloalkenyl, C3- or C4-alkynyl or C3-C6cycloalkyl;
• R2 is hydrogen, C1-C4alkyl, C1-C4haloalkyl, C3-C6alkenyl, C3-C6haloalkenyl, C3-C6alkynyl, C1-C4alkyl-S(O)2— or C1-C4haloalkyl-S(O)2—;
• R3 is hydrogen, C1-C4alkyl, C1-C4haloalkyl, C2-C6alkenyl, C2-C6haloalkenyl, C2-C6alkynyl, halogen, cyano, NH2C(S)—, nitro or amino;
• n, is 0, 1 or 2;
• R4 is hydrogen, C1-C4alkyl, C1-C4haloalkyl, C3-C6alkenyl, C3-C6haloalkenyl, C3-C6alkynyl or C3-C6cycloalkyl;
• R5 is hydrogen, halogen, C1-C4alkyl, C1-C4haloalkyl, cyano, nitro, amino, NH2C(O)—, NH2C(S)—, C1-C4alkylcarbonyl, C1-C6alkoxycarbonyl, C1-C4haloalkylcarbonyl, C2-C4allenylcarbonyl, C1-C3alkyl-CH(OH)—, OHC—, HOC(O)—, ClC(O)—, HON═CH—, C1-C4alkoxy-N═CH—, C2-C4haloalkenylcarbonyl or C2-C4alkynylcarbonyl;
• R11 is hydrogen, fluorine, chlorine, bromine or methyl;
• R12 is hydrogen, halogen, methyl, halomethyl, nitro, amino, hydroxy, OHC—, HOC(O)—, cyano, C1-C4alkoxycarbonyl or halomethoxy;
• X1 is O, S, R20N═ or R25ON═;
• R13 is hydroxy, C1-C6alkoxy, C3-C6alkenyloxy, C3-C6alkynyloxy, C1-C6haloalkoxy, C3-C6-haloalkenyloxy, C1-C6alkoxy-C1-C6alkyl, C3-C6alkenyloxy-C1-C6alkyl, C3-C6alkynyloxy-C1-C6alkyl, C1-C6alkoxy-C1-C6alkoxy-C1-C6alkyl, B1—C1-C6alkoxy, R2,(R22)N—, C1-C6alkyl, C3-C6alkenyl, C3-C6alkynyl, C2-C6haloalkyl, C3-C6haloalkenyl, C3-C6cycloalkyl, C3-C6halocycloalkyl, B1—C1-C6alkyl, OHC—, C1-C6alkylcarbonyl, C1-C6alkylcarbonyloxy, C1-C6haloalkylcarbonyl, C2-C6alkenylcarbonyl, C1-C6alkoxycarbonyl, C1-C6alkyl-S(O)2—, C1-C6haloalkyl-S(O)2—, (C1-C6alkyl)2N—N═CH—,
• B1—CH═N—, (CH3)2N—CH═N—, (C1-C5hydroxyalkyl)—CH2—, (B1—C1-C5hydroxyalkyl)—CH2—, (B1—C1-C5haloalkyl)—CH2—, (hydroxy-C1-C5alkyl)—O— or (B1—C1-C5hydroxyalkyl)—O—;
• B1 is cyano, OHC—, HOC(O)—, C1-C6alkylcarbonyl, C1-C6alkoxycarbonyl, C3-C6alkenyloxycarbonyl, C3-C6alkynyloxycarbonyl, benzyloxycarbonyl, benzyloxycarbonyl mono- to tri-substituted at the phenyl ring by halogen, C1-C4alkyl or by C1-C4haloalkyl, benzylthiocarbonyl, benzylthiocarbonyl mono- to tri-substituted at the phenyl ring by halogen, C1-C4-alkyl or by C1-C4haloalkyl, C1-C6haloalkoxycarbonyl, C1-C6alkylthio-C(O)—, R26(R27)NC(O)—, phenyl, phenyl mono- to tri-substituted by halogen, C1-C4alkyl or by C1-C4haloalkyl, C1-C6-alkyl-S(O)2—, C1-C6alkyl-S(O)—, C1-C6alkylthio, C3-C6cycloalkyl, C1-C6alkoxy, C3-C6alkenylthio or C3-C6alkynylthio;
• R20 is hydrogen, C1-C6alkyl, C3-C6alkenyl, C3-C6alkynyl, C2-C6haloalkyl, cyano, R23(R24)N—, C1-C6alkoxycarbonyl, C3-C6alkenyloxycarbonyl, C3-C6alkynyloxycarbonyl, C2-C6haloalkoxycarbonyl, OHC—, C1-C6alkylcarbonyl, C1-C6haloalkylcarbonyl, C1-C6alkyl-S(O)2—, C1-C6haloalkyl-S(O)2—, phenyl, phenyl mono- to tri-substituted by halogen, C1-C4alkyl or by C1-C4haloalkyl, phenyl-C1-C6alkyl, or phenyl-C1-C6alkyl mono- to tri-substituted at the phenyl ring by halogen, C1-C4alkyl or by C1-C4haloalkyl;
• R21 and R22 are each independently hydrogen, C1-C6alkyl, C3-C6alkenyl, C3-C6alkynyl, C1-C6-haloalkyl, C3-C6haloalkenyl, C3-C6cycloalkyl, C1-C6alkoxy-C1-C6alkyl, OHC—, C1-C6alkylcarbonyl, C1-C6haloalkylcarbonyl, C1-C6alkyl-S(O)2— or C1-C6haloalkyl-S(O)2—;
• R23 and R24 are each independently as defined for R21;
• R25 is hydrogen, C1-C6alkyl, C3-C6alkenyl, C3-C6alkynyl, C1-C6haloalkyl, C3-C6haloalkenyl, C1-C6alkoxy, C1-C6alkyl, benzyl, C1-C6alkyl-S(O)2— or C1-C6haloalkyl-S(O)2—;
• R26 and R27 are each independently hydrogen, C1-C6alkyl, C3-C6alkenyl, C3-C6alkynyl, C1-C6haloalkyl, C3-C8haloalkenyl, phenyl, phenyl mono- to tri-substituted by halogen, C1-C4alkyl or by C1-C4haloalkyl, benzyl, or benzyl mono- to tri-substituted at the phenyl ring by halogen, C1-C4alkyl or by C1-C4haloalkyl;
• or a pyrazole N-oxide, an agrochemically acceptable salt or a stereoisomer of that compound of formula I.