[Synthesis]
General procedure for the synthesis of 1-[3-(difluoromethoxy)phenyl]ethanone from difluoromethyl trifluoromethanesulfonate and 3'-bromoacetophenone:[a] The reaction was carried out at 0.5 mmol, after which the yield was determined by 19F NMR spectroscopy, with the addition of PI1CF3 as an internal standard. Note: The reaction was hydroxylated under an inert atmosphere according to literature procedures. [Anderson, K. W.; Ikawa, T.; Tundel, R. E.; Buchwald, S. L. J. Am. Chem. Soc.] For oven-dried 4 mL vials, Pd2(dba)3 (9.2 mg, 0.010 mmol, 4.0 mol% Pd), 2-di-tert-butylphosphino-2',4',6' -triisopropylbiphenyl (tBu-XPhos, 17.0 mg, 0.040 mmol, 8.0 mol%), KOH (1.0-3.0 equiv), degassed H2O (150-300 μL), and dioxane (250-500 μL). Aryl halides (0.5 mmol, 1.0 eq.) were added (solid aryl halides were weighed into the vial prior to solvent addition and liquid aryl bromides were added via syringe after solvent addition). The vials were sealed with Teflon-lined caps and heated at 100°C for 1-18 hours. After completion of the reaction, the solution was allowed to cool and acetonitrile (500-750 μL, making a total volume of 1.0 mL of dioxane and acetonitrile) and 6 M KOH (700-850 μL, making a final volume of 1.0 mL of aqueous solvent) were added. The resulting mixture was stirred rapidly at room temperature and HCF2O2 (210 μL, 1.5 mmol, 3.0 eq.) was added immediately. Note: The reaction is exothermic. The mixture was stirred vigorously for 2 minutes. The reaction mixture was diluted with H2O (8 mL) and extracted with ether (2 x 8 mL). The combined organic layers were dried over MgSO4, concentrated, and purified by silica gel chromatography. |