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

Temperature

80 °C

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)+.

1. temperatureis cooled to room temperature
2. filtrationThis mixture is filtered
3. concentrationthe filtrate is concentrated under reduced pressure
4. extractionextracted with EtOAc (3×50 mL)
5. washThe organic phase is washed with water and saline
6. dry with materialdried over MgSO4
7. concentrationconcentrated under reduced pressure

ORD record

ord-be67110598dc432aa6372ddb603d00e6

Source dataset

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07645781B2