Hydrochloric Acid → 6-Hydroxy-2H-1,4-benzoxazin-3(4H)-one

HRID 1190778Notes

Reaction equation

HRID 1190778 reaction equation
[H-].[Na+].Cl[CH2:4][C:5]([NH:7][C:8]1[CH:13]=[C:12]([OH:14])[CH:11]=[CH:10][C:9]=1[OH:15])=[O:6].Cl>C1COCC1>[OH:14][C:12]1[CH:11]=[CH:10][C:9]2[O:15][CH2:4][C:5](=[O:6])[NH:7][C:8]=2[CH:13]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 24758Sodium hydrideHCID 212986772-Chloro-N-(2,5-dihydroxy-phenyl)-acetamide

Product 1

HCID 113786896-Hydroxy-2H-1,4-benzoxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Sodium hydride (60%) (1.6 g, 39.68 mmol) was added to a THF solution of compound 47 (2.5 g, 12.4 mmol) at 0° C. The reaction mixture was warmed to room temperature and left for 12 h. Excess sodium hydride was destroyed by careful addition of ice-water. The crude reaction mixture was acidified by the addition 1M HCl. The reaction mixture was extracted in EtOAc (6×50 ml). Solvent was evaporated to yield a brownish solid which was used for the next step without further purification. Yield=1.61 g. (78%). 1H NMR (dmso-d6): 10.5 (s, 1H), 9.14 (s, 1H), 6.71 (d, 1H, J=8.86 Hz), 6.34 (d, 1H, J=2.73 Hz), 6.26 (dd, 1H, J=8.83 and 2.62 Hz), 4.41 (s, 1H). 13C NMR (dmso-d6): 166.1, 153.2, 136.5, 128.5, 117.2, 109.8, 103.5, 67.5. ES-HRMS [M+H]+ 166.0500. Calcd for (C8H8NO3): 166.0478.

Workup

  1. customExcess sodium hydride was destroyed by careful addition of ice-water
  2. customThe crude reaction mixture
  3. extractionThe reaction mixture was extracted in EtOAc (6×50 ml)
  4. customSolvent was evaporated
  5. customto yield a brownish solid which
  6. customwas used for the next step without further purification

Sources & evidence

ORD record
ord-afe3306d6f2b4ac5b1c64e5deca8dc5c
Source dataset
uspto-grants-2014_03
Patent number
US08679776B2

Reaction notes

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