Dimethylformamide → 6-Chloro-8-nitro-2H-benzo[b][1,4]oxazin-3(4H)-one

HRID 1505193Notes

Reaction equation

HRID 1505193 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[C:4]([N+:9]([O-:11])=[O:10])[C:3]=1[OH:12].CN([CH:16]=[O:17])C.[C:18]([O-])([O-])=O.[K+].[K+]>>[Cl:8][C:6]1[CH:5]=[C:4]([N+:9]([O-:11])=[O:10])[C:3]2[O:12][CH2:18][C:16](=[O:17])[NH:1][C:2]=2[CH:7]=1

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 11430Potassium CarbonateHCID 43482942-Amino-4-chloro-6-nitrophenol

Product 1

HCID 116515356-Chloro-8-nitro-2H-benzo[b][1,4]oxazin-3(4H)-oneYield 19%

Procedure

To a solution of 2-amino-4-chloro-6-nitrophenol (5 g, 26.5 mmol) in DMF (20 ml) ethylbromoacetate (3 ml, 26.5 mmol) and K2CO3 (4 g, 29.15 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 NaOH 5%, water and brine. The organic phase was dried over sodium sulfate and concentrated under vacuum. The purification of the crude residue by crystallization from ether/AcOEt gave 1.13 g of a beige solid. Yield: 19%. 1HNMR (DMSO, 200 MHz) δ 4.79 (2H, s), 7.15 (1H, d, J=2.6 Hz), 7.66 (1H, d, J=2.8 Hz), 11.21 (1H, bs)

Workup

  1. customThe solvent was evaporated
  2. dissolutionthe crude was dissolved in AcOEt (30 ml)
  3. washwashed with NaOH 5%, water 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/AcOEt

Sources & evidence

ORD record
ord-1bd52bbbe8ee4d6c9ea40786b720f98f
Source dataset
uspto-grants-2015_12
Patent number
US09216975B2

Reaction notes

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