(Diethylamino)sulfur trifluoride → 3-fluoro-1,3-dihydro-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one

Participants

Reaction Steps

A well stirred suspension of 3.6 g (0.012 mole) of 1,3-dihydro-3-hydroxy-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one in 200 ml methylene chloride was cooled to -70°, and 5 ml (0.04 mole) of diethylaminosulfur trifluoride was added dropwise. The reaction mixture was allowed to warm slowly to -10°, at which temperature all of the solid went into solution. The reaction mixture was poured into 400 ml of ice water, and the organic layer was separated, washed with water, dried (MgSO4) and evaporated to dryness under reduced pressure. The residue was recrystallized from benzene-heptane to give 3.0 g (83%) of 3-fluoro-1,3-dihydro-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one as colorless crystals: mp 174°-175° (dec.); 1H nmr (DMSO-d6) δ 5.90 ppm (d, J = 57 Hz, 1H), 7.3-7.7 ppm (m, 6H), 8.07 ppm (d, J = 2.5 Hz, 1H) and 8.45 ppm (d, d, J = 9.0, 2.5 Hz, 1H); 19F nmr (DMSO-d6) δ -161.4 ppm (d, J = 57 Hz).

Provenance & Evidence