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

HRID 896146Notes

Reaction equation

[CH3:1][N:2]1[C:7]2[CH:8]=[CH:9][C:10]([N+:12]([O-])=O)=[CH:11][C:6]=2[O:5][CH2:4][C:3]1=[O:15].[Cl-].[NH4+].C(Cl)Cl>CCO.O.[Fe]>[CH3:1][N:2]1[C:7]2[CH:8]=[CH:9][C:10]([NH2:12])=[CH:11][C:6]=2[O:5][CH2:4][C:3]1=[O:15]

Participants

Conditions

Temperature: 80 °C

Procedure

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)+.

Workup

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

Sources & evidence

ORD record: ord-87a17b8d403f4975805c57249d8aae28
Source dataset: uspto-grants-2005_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06919329B2

Reaction notes

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