Method for producing 7-(pyrazole-3-yl) benzoxazoles

A process for preparing 7-(pyrazol-3-yl)benzoxazoles of the formula I

• in which the variables R1-R6 are as defined below:
• R1 is hydrogen, C1-C4-alkyl or C1-C4-haloalkyl;
• R2 is cyano, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-haloalkoxy, C1-C4-alkylthio, C1-C4-haloalkylthio, C1-C4-alkylsulfinyl, C1-C4-haloalkylsulfinyl, C1-C4-alkylsulfonyl or C1-C4-haloalkylsulfonyl;
• R3 is hydrogen, halogen, cyano, C1-C4-alkyl or C1-C4-haloalkyl;
• R4 is halogen;
• R5 is fluorine, chlorine or cyano;
• R6 is hydrogen, C1-C6-alkyl, C1-C6-haloalkyl, C2-C6-alkenyl, C2-C6-haloalkenyl, C2-C6-alkynyl, C1-C4-alkoxy-C1-C4-alkyl, C1-C4-cyanoalkyl, C1-C4-alkylthio-C1-C4-alkyl, (C1-C4-alkoxy)carbonyl-C1-C4-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkyl-C1-C4-alkyl, C3-C8-cycloalkyloxy-C1-C4-alkyl, phenyl, phenyl-C1-C4-alkyl, or where each cycloalkyl, phenyl and heterocyclyl ring can be unsubstituted or may carry one, two or three substituents selected independently of one another from the group consisting of cyano, nitro, amino, hydroxyl, carboxyl, halogen, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-haloalkoxy, C1-C4-alkylthio;
• which comprises reacting a 2-halo-3-(pyrazol-3-yl)anilide of the formula II
• in which the variables R1-R6 are as defined above and X is bromine or iodine in the presence of a copper(I) compound and a base to give a compound of the formula I, wherein the molar ratio of copper(I) compound to the compound II used is <1:1.