Trifluoromethanesulfonic anhydride → HCID 86704529, compound

Participants

Reaction Steps

A stirred solution of N-(2-fluoro-5-nitrophenyl)cyclopropanecarboxamide (210 mg, 1.0 mmol) in MeCN (6 mL) under nitrogen was cooled to −10 to −20° C. (ice/MeOH bath) and a precipitate developed. Tf2O (0.34 mL, 2.0 mmol) was added dropwise over 3-5 min (a solution developed). The mixture was stirred in the cold bath for a further 2 min then TMS-N3 (0.53 mL, 4.0 mmol) was added dropwise over 2 min (bath temp ca. −10° C.). After complete addition, the mixture was stirred for 90 min (bath temperature ca. 15° C.). The mixture was worked-up by addition of EtOAc (30 mL) and saturated NaHCO3 (15 mL). After stifling for 2 min, the mixture was placed in a separating funnel and H2O (30 mL) added. The aqueous and organic layers were partitioned and the aqueous layer extracted with EtOAc (2×20 mL). The combined organic layers were dried (Na2SO4), filtered and the solvent removed under vacuum to leave a crude residue. The residue was dry-loaded on to silica gel then purified by column chromatography on silica gel using EtOAc/heptane (2:8 to 4:6) as eluent to give the desired product (112 mg, 45% yield).

Provenance & Evidence