4'-Fluoropropiophenone

5724-03-8

456-03-1

General procedure for the synthesis of 4'-fluoropropiophenone from 1-(4-fluorophenyl)prop-2-en-1-ol: Under nitrogen protection, the ruthenium complex [RuCl2(6-C6H6)(PTA-Me)] (3a) (0.02-0.1 mmol; 0.5-2.5 mol%) and K2CO3 (0.05-0.25 mmol) were added to a solution of 1-(4-fluorophenyl)prop-2-en-1-ol (4a-o, 4 mmol) in tetrahydrofuran (4mL). -fluorophenyl)prop-2-en-1-ol (4a-o, 4 mmol) in a solution of tetrahydrofuran (4 mL). The reaction mixture was placed in a sealed tube and stirred at 75°C for the indicated time (see Table 4 and Scheme 3). The progress of the reaction was monitored by sampling and diluting 10 μL of the sample with dichloromethane (3 mL) every ~1 hr followed by GC analysis. Upon completion of the reaction, the mixture was cooled to room temperature, at which point the ruthenium complex 3a partially precipitated. The solids were removed by filtration and the reaction products were subsequently separated by solvent evaporation. The residue was purified using silica gel column chromatography with EtOAc-hexane (1:10) mixed solvent as eluent. The structure of the resulting carbonyl compounds 5a-o was confirmed by GC/MS analysis of their fragmentation patterns, NMR spectroscopy, and comparison of retention times of commercially pure samples (Sigma-Aldrich or Acros Organics).