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

Temperatur

80 °C

To a stirred suspension of 4-methyl-7-nitro-2H-1,4-benzoxazin-3-one (DE 19802239, 2.43 g, 11.67 mmol) in EtOH (20 mL) and water (10 mL) is added ammonium chloride (6.25 g, 116.70 mmol). To this mixture is added iron (1.95 g, 35.00 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 (100 mL). The resulting mixture is filtered through celite and the filtrate is further diluted with water (100 mL). The organic layer is separated followed by further extraction of the aqueous phase with CH2Cl2 (3×50 mL). The organic phases are combined, dried over Na2SO4 and concentrated under reduced pressure, and the product is purified by silica gel column chromatography (EtOAc) to give the title compound in quantitative yield, MS m/z 179.1 (M+H)+.

1. temperatureis cooled to room temperature
2. filtrationThe resulting mixture is filtered through celite
3. additionthe filtrate is further diluted with water (100 mL)
4. customThe organic layer is separated
5. extractionfollowed by further extraction of the aqueous phase with CH2Cl2 (3×50 mL)
6. dry with materialdried over Na2SO4
7. concentrationconcentrated under reduced pressure
8. customthe product is purified by silica gel column chromatography (EtOAc)

ORD-Eintrag

ord-e39d12c90b914782944f8a9dc9d3a6d6

Quelldatensatz

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07645781B2