Dichloromethane → 2,2-difluoro-4-methyl-7-amino-4H-1,4-benzoxazin-3-one

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 2,2-difluoro-4-methyl-7-nitro-4H-1,4-benzoxazin-3-one (Step 1, 1.3 g, 5.32 mmol) in EtOH (20 mL) and water (10 mL) is added ammonium chloride (2.85 g, 53.32 mmol). To this mixture is added iron (892 mg, 15.09 mmol) in 3 equal portions. The resulting mixture is heated to 80° C. for 2 h at which time the reaction is cooled to room temperature followed by addition of CH2Cl2 (50 mL). The resulting mixture is filtered through celite and the filtrate is further diluted with water (50 mL). The organic layer is separated followed by further extraction of the aqueous phase with CH2Cl2 (50 mL×3). The combined organic phase is dried over Na2SO4 and concentrated under reduced pressure, and the residue is purified by passing it through a short silica gel column with EtOAc to give the title compound (1.05 g, Quant.), MS (m/z): 215.5 [M+H]+.

Provenance & Evidence