[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:10]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:12]=1)[C:6]([O:8]C)=O.[CH3:17][NH:18][O:19][CH3:20].C([Mg]Cl)(C)C>C1COCC1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:10]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:12]=1)[C:6]([N:18]([O:19][CH3:20])[CH3:17])=[O:8]Methyl 3-methoxy-5-trifluoromethylbenzoate (O4.014, 1 g) and N,O-dimethylhydroxylamine (416 mg) were initially charged in THF (30 ml). Thereafter, the mixture was cooled to −15° C., and isopropylmagnesium chloride (3.2 ml; 2 M in THF) was added dropwise within 10 min. The mixture was stirred at −15° C. for another 20 min before the cooling bath was removed. After 3 h, the mixture was cooled again to −15° C. and further isopropylmagnesium chloride (3.2 ml) was added. After the cooling bath had been removed, the mixture was stirred at RT for another hour, then admixed with 20% ammonium chloride solution and extracted three times with EA. The combined EA phases were dried over sodium sulfate, filtered and concentrated. The residue was purified using silica gel (50 g cartridge, DCM as eluent). 465 mg of the title compound were obtained, as well as 427 mg of reactant.
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