A process is described for preparing isoxazoles of the formula I where the substituents are as defined below: R1 is hydrogen, C1-C6-alkyl, R2 is C1-C6-alkyl, R3, R4, R5 are hydrogen, C1-C6-alkyl, or R4 and R5 together form a bond, R6 is a heterocyclic ring, n is 0, 1 or 2; which comprises preparing an intermediate of the formula VI where R1, R3, R4 and R5 are as defined above, followed by halogenation, thiomethylation, oxidation and acylation to give compounds of the formula I. Also novel intermediates for preparing the compounds of the formula I and novel processes for preparing the intermediates are described.