A process is described for preparing isoxazoles of the formula I wherein 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; in which an intermediate of the formula VI  is prepared, followed by halogenation, thiomethylation, oxidation and acylation to give compounds of formula I. Novel intermediates for preparing the intermediates are described.