Dimethylformamide → 5-Nitro-2H-1,4-benzoxazin-3(4H)-one

HRID 1505189Notes

Reaction equation

HRID 1505189 reaction equation
[NH2:1][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][CH:5]=[CH:4][C:3]=1[OH:11].CN([CH:15]=[O:16])C.[C:17]([O-])([O-])=O.[K+].[K+]>>[N+:8]([C:7]1[C:2]2[NH:1][C:15](=[O:16])[CH2:17][O:11][C:3]=2[CH:4]=[CH:5][CH:6]=1)([O-:10])=[O:9]

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 11430Potassium CarbonateHCID 41154952-Amino-3-Nitrophenol

Product 1

HCID 107741655-Nitro-2H-1,4-benzoxazin-3(4H)-oneYield 80%

Procedure

To a solution of 2-amino-3-nitrophenol (4.62 g, 30 mmol) in DMF (20 ml) ethylbromoacetate (3.3 ml, 30 mmol) and K2CO3 (4.56 g, 33 mmol) were added and the reaction was stirred at room temperature for 20 hours. The solvent was evaporated and the crude was dissolved in AcOEt (30 ml) and washed with water (1×20 ml) and brine. The organic phase was dried over sodium sulfate and concentrated under vacuum. The purification of the crude residue by crystallization from ether/hexane gave 4.65 g of a yellow solid. Yield: 80%. 1HNMR (DMSO, 200 MHz) δ 4.74 (2H, s), 7.15 (1H, t, J=8.4 Hz), 7.41 (1H, dd, J=8.2 Hz, J′=1.6 Hz), 7.77 (1H, dd, J=8.4 Hz, J′=1.2 Hz), 10.38 (1H, bs)

Workup

  1. customThe solvent was evaporated
  2. dissolutionthe crude was dissolved in AcOEt (30 ml)
  3. washwashed with water (1×20 ml) and brine
  4. dry with materialThe organic phase was dried over sodium sulfate
  5. concentrationconcentrated under vacuum
  6. customThe purification of the crude residue
  7. customby crystallization from ether/hexane

Sources & evidence

ORD record
ord-5fe98de1d2dc4db984424a6a2cbd60f5
Source dataset
uspto-grants-2015_12
Patent number
US09216975B2

Reaction notes

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