Lawesson's reagent → 5-(5-Bromo-2-fluorophenyl)-6,6-difluoro-5-methyl-1,4-oxazepane-3-thione
Reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:19])=[C:6]([C:8]2([CH3:18])[C:14]([F:16])([F:15])[CH2:13][O:12][CH2:11][C:10](=O)[NH:9]2)[CH:7]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:29])=CC=1>C1COCC1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:19])=[C:6]([C:8]2([CH3:18])[C:14]([F:16])([F:15])[CH2:13][O:12][CH2:11][C:10](=[S:29])[NH:9]2)[CH:7]=1Participants
4
Procedure
To a solution of 5-(5-bromo-2-fluorophenyl)-6,6-difluoro-5-methyl-1,4-oxazepan-3-one (2.0 g, 5.93 mmol) in THF (25 mL) was added Lawesson's reagent (2.87 g, 7.1 mmol) at rt and heated to reflux temperature for 16 h. Reaction mixture was concentrated under reduced pressure and directly purified by column chromatography on silica gel using 4% ethyl acetate in Hexane to furnish title compound as colorless gum. Yield=1.0 g (50%). LCMS: RtH8=1.75 [M+H]+=354.8, 355.7,