Ammonium Chloride → 7-Amino-4-methyl-4h-benzo[1,4]thiazin-3-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3,4-dihydro-4-methyl-7-nitro-2H-1,4-benzothiazin-3-one (4.50 g, 20.07 mmol) in EtOH (100 mL) and water (50 mL) is added ammonium chloride (10.76 g, 200.7 mmol). To this mixture is added iron (3.37 g, 60.21 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. This mixture is filtered and the filtrate is concentrated under reduced pressure and extracted with EtOAc (3×50 mL). The organic phase is washed with water and saline, dried over MgSO4, and concentrated under reduced pressure to give the title compound (for reference see DE 19802239) as a dark brown oil (3.60 g, 93%), MS m/z 195.5 (M+H)+.

Provenance & Evidence