N-(3-Acetyl-5-pentafluorosulfanylphenyl)-2,2,2-trifluoroacetamide (100 mg, example 4d) was dissolved in absolute dimethoxyethane (5 ml) in a microwave insert and admixed with powdered potassium carbonate (40 mg). After adding iodoethane (60 μl), the mixture was heated to 100° C. in the microwave for 30 min. Subsequently, further iodomethane (60 μl) was added and the mixture was heated again to 100° C. for 30 min. This operation was repeated once more. Then the mixture was worked up by adding it to a mixture of water, ethyl acetate and 1 N HCl. Removal of the organic phase was followed by extraction three times more with ethyl acetate. The combined extracts were dried over magnesium sulfate, filtered and concentrated. The residue was purified by means of preparative HPLC. The product-containing fractions were combined, freed of the acetonitrile and extracted three times with ethyl acetate. The combined extracts were dried over magnesium sulfate, filtered and concentrated. 50 mg of the desired compound were obtained.
