3-(trifluoromethoxy)propyl trifluoromethanesulfonate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-ethyl-3-hydroxy-benzoic acid methyl ester (250 mg, 1.32 mmol), crude trifluoro-methanesulfonic acid 3-trifluoromethoxy-propyl ester (590 mg, 1.58 mmol; purity of 74%) and anhydrous K2CO3 (276 mg, 1.98 mmol) in MeCN (2.0 mL) is stirred in a sealed glass vial overnight at room temperature. The crude product obtained after filtration and evaporation is purified by flash chromatography (hexane/AcOEt 1:1) to give the title compound as oil. TLC, Rf (hexane/AcOEt 3:1)=0.38. 1H-NMR (CDCl3): δ 1.24 (t, 3H), 2.25 (m, 2H), 2.70 (q, 2H), 3.94 (s, 3H), 4.18 (t, 2H), 4.24 (t, 2H), 7.25 (d, 1H), 7.52 (s, 1H), 7.64 (d, 1H) ppm. 19F-NMR (CDCl3): δ −61.1 ppm. The crude product obtained after filtration and evaporation is purified by flash chromatography (hexane/AcOEt 1:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 5-bromo-2-methoxy-phenol (1.20 g, 5.62 mmol), crude trifluoro-methanesulfonic acid 3-trifluoromethoxy-propyl ester (2.52 g, 6.74 mmol; purity of 74%) and anhydrous K2CO3 (1.18 g, 8.42 mmol) in MeCN (8 mL) is stirred in a sealed flask at room temperature overnight and then filtered. The combined filtrates are concentrated and the crude product is chromatographed over silica gel (eluent: toluene) to give the title compound as oil. TLC, Rf (toluene/AcOEt 10:1)=0.63. 1H-NMR (CDCl3): δ 2.25 (m, 2H), 3.87 (s, 3H), 4.13 (m, 2H), 4.23 (m, 2H), 6.79 (dd, 1H), 7.04 (d,1H), 7.09 (dd, 1H) ppm. 19F-NMR (CDCl3): zδ −60.7 ppm. filtered The combined filtrates are concentrated the crude product is chromatographed over silica gel (eluent: toluene)