Urea → 3,7-Dibromodibenzo[b,d]furan

HRID 71908Notes

Reaction equation

HRID 71908 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][C:11]([Br:14])=[CH:10][C:9]=2[O:15]C)=[C:4](N)[CH:3]=1.N([O-])=O.[Na+].NC(N)=O>OS(O)(=O)=O.O>[Br:14][C:11]1[CH:12]=[CH:13][C:8]2[C:5]3[CH:4]=[CH:3][C:2]([Br:1])=[CH:7][C:6]=3[O:15][C:9]=2[CH:10]=1

Participants

6

Reactant 3

HCID 1176UreaHCID 99984202-Methoxy-2'-amino-4,4'-dibromobiphenylHCID 23668193Sodium Nitrite

Product 1

HCID 5263563,7-Dibromodibenzo[b,d]furanYield 71.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

To a suspension of 4,4′-Dibromo-2′-methoxy-biphenyl-2-ylamine (3.5 g, 9.8 mmol) in H2SO4 (2.4 g) and water (8.5 ml) at 0° C. was added slowly a solution of NaNO2 (682 mg, 9.8 mmol) in water (9 ml). The mixture was stirred at 0° C. for 2 hours. Urea (1.2 g, 20 mmol) was added and the mixture was stirred for 12 hours. The mixture was diluted with water and was heated at 70° C. for 24 hours. The mixture was cooled to 25° C. and was filtered. The collected solid was re-crystallized from benzene/methanol to give 3,7-dibromo-dibenzofuran (2.27 g).

Workup

  1. stirringthe mixture was stirred for 12 hours
  2. temperaturewas heated at 70° C. for 24 hours
  3. temperatureThe mixture was cooled to 25° C.
  4. filtrationwas filtered
  5. customThe collected solid was re-crystallized from benzene/methanol

Sources & evidence

ORD record
ord-250e64dd0c8a492d9bd4d806bc54a253
Source dataset
uspto-grants-2014_09
Patent number
US08822430B2

Reaction notes

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