Dimethylformamide → Tert-butyl 3-fluoro-3-(4-formylphenyl)azetidine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl-3-(4-bromophenyl)-3-fluoroazetidine-1-carboxylate (Preparation 5, 1.0 g, 3 mmol) in THF (10 mL) at −78° C. was slowly added n-BuLi (2.1 mL of 1.6M solution in hexanes). The reaction was stirred at −78° C. for 15 minutes at which time DMF (0.5 mL, 6 mmol) was added. Reaction mixture was allowed to warm to room temperature and stir for additional 1 hour. Saturated aqueous NH4Cl (10 mL) was added and the aqueous phase was extracted with ether (2×10 mL). The combined organic phases were dried (Na2SO4) and concentrated under vacuum. Crude product was chromatographed on silica (12 g column) using a gradient of 0-30% EtOAc/hexanes in a 12 minute run. Yield 460 mg. LC/MS retention time=3.004 minutes; MS calculated for (C15H18FNO3), 279.127; found 180.2 M-BOC. 1H NMR (CDCl3) δ 10.0 (s, 1H), 8.0 (d, 2H), 7.7 (d, 2H), 4.5 (m, 2H), 4.2 (m, 2H), 1.6 (s, 9H).

Provenance & Evidence