CON(C)[C:4](=[O:24])[C:5]1[CH:10]=[C:9]([NH:11][C:12](=[O:17])[C:13]([F:16])([F:15])[F:14])[CH:8]=[C:7]([S:18]([F:23])([F:22])([F:21])([F:20])[F:19])[CH:6]=1.[CH3:26][Si]([N-][Si](C)(C)C)(C)C.[Li+].C[Mg]Br>C1COCC1>[C:4]([C:5]1[CH:10]=[C:9]([NH:11][C:12](=[O:17])[C:13]([F:15])([F:16])[F:14])[CH:8]=[C:7]([S:18]([F:20])([F:19])([F:22])([F:23])[F:21])[CH:6]=1)(=[O:24])[CH3:26]N-Methoxy-N-methyl-3-(pentafluorosulfanyl)-5-(2,2,2-trifluoroacetylamino)benzamide (O4.075; 1.65 g) was dissolved in THF (25 ml). At 0° C., lithium bis(trimethylsilyl)amide (0.9 ml) was added while stirring. After 30 min, methylmagnesium bromide (3.5 ml, 3 M in diethyl ether) was added dropwise. After the addition had ended, the ice bath was removed and the mixture was stirred at RT for 2 h. While cooling, 1 N hydrochloric acid, water and EA were then added. After removing the organic phase, the aqueous phase was extracted twice more with EA. The combined EA phases were dried with magnesium sulfate, filtered and concentrated. The crude product is a mixture of N-(3-acetyl-5-pentafluorosulfanyl-phenyl)-2,2,2-trifluoroacetamide and 1-[3-amino-5-(pentafluorosulfanyl)phenyl]ethanone, and so the crude product (1.3 g) was taken up in methylene chloride (60 ml) and admixed with triethylamine (155 μl). Thereafter, trifluoroacetic anhydride (160 μl) was added while stirring. After stirring at RT for 3 h, water and saturated sodium hydrogencarbonate solution were added, the phases were separated and the DCM phase was washed three times more with water. The DCM phase was dried with magnesium sulfate, filtered and concentrated. 1.3 g of the title compound were obtained.
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