Tetramethylammonium fluoride → 6-[2-(2-Chloro-5-methoxy-phenyl)-1-hydroxy-1-trifluoromethyl-propyl]-4-methyl-4H-benzo[1,4]oxazin-3-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-[2-(2-chloro-5-methoxy-phenyl)-propionyl]-4-methyl-4H-benzo[1,4]oxazin-3-one (1.17 g) in tetrahydrofuran (60 ml) was added a solution of (trifluoromethyl)trimethylsilane (703 mg) in tetrahydrofuran (10 ml) at 0° C. Tetramethylammonium fluoride (30 mg) was added and the mixture was stirred at 0° C. for 30 min and at room temperature for 15 min. A 1 M solution of tetrabutylammonium fluoride in tetrahydrofuran (3.26 ml) was added and the mixture was stirred for 20 min. The solvent was evaporated and the residue was dissolved in dichloromethane. The organic phase was washed with water, dried (MgSO4), filtered and concentrated. The product was purified by chromatography (SiO2, cyclohexane/EtOAc 1:0=>7:3) to give the title compound (1.1 g) as a colorless solid. MS (m/e, ISP neg. ion)=428.4 [M−H+].

Provenance & Evidence