Tetrahydrofuran → tert-Butyl 3-(fluoro(phenylsulfonyl)methylene)azetidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a mixture of fluoromethyl phenyl sulfone (0.50 g, 2.9 mmol) and phosphorochloridic acid, diethyl ester (0.415 mL, 2.87 mmol) in tetrahydrofuran (6 mL, 70 mmol) was added 1.000 M of lithium hexamethyldisilazide in tetrahydrofuran (6.2 mL, 6.2 mmol) dropwise at −78° C. After the mixture was stirred at −78° C. for 1 h, a solution of tert-butyl 3-oxoazetidine-1-carboxylate (0.378 g, 2.21 mmol) in tetrahydrofuran (1.3 mL, 16 mmol) was added. The reaction was allowed to warm to ambient temperature and stirred for 2 h at rt. The reaction was poured into an ice-cold mixture of EtOAc and sat. ammonium chloride. The organic layer was separated and the aq. layer was extracted with EtOAc. The combined organic layers were washed with brine, and dried over sodium sulfate. The solvent was removed under reduced pressure and the resulting residue was purified on silica gel, eluting with 0 to 50% EtOAc in hexane, to give the desired product (560 mg, 77.5%). LCMS calculated for C15H18FNO4SNa(M+Na)+: m/z=350.1; Found (M+Na) 350.3.

Provenance & Evidence