Hydrochloric Acid → 4-Dibenzofuranol

HRID 2383970Notes

Reaction equation

HRID 2383970 reaction equation
[CH:1]1[C:9]2[C:8]3[CH:10]=[CH:11][CH:12]=[CH:13][C:7]=3[O:6][C:5]=2[CH:4]=[CH:3][CH:2]=1.CN(C)CCN(C)C.[Li]CCCC.B(OCCCC)(OCCCC)[O:28]CCCC.OO.Cl>C(OCC)C>[CH:1]1[C:9]2[C:8]3[CH:10]=[CH:11][CH:12]=[CH:13][C:7]=3[O:6][C:5]=2[C:4]([OH:28])=[CH:3][CH:2]=1

Participants

8

Reactant 6

HCID 313Hydrochloric AcidHCID 568DibenzofuranHCID 784Hydrogen PeroxideHCID 8037N,N,N',N'-TetramethylethylenediamineHCID 12712Tributyl borateHCID 178418339Butyllithium

Product 1

HCID 30150514-Dibenzofuranol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of dibenzofuran (50 g, 0.29 mol) in 1000 ml dry diethyl ether and N,N,N′,N′-tetramethylethane-1,2-diamine (70 ml, 0.43 mol) (TMEDA), 1.6M BuLi (235 ml, 0.32 mol) in hexanes was added with stirring under Nitrogen. The mixture was refluxed for 1 hour (yellow precipitate) and then cooled to 0° C. Tributyl borate (120 ml, 0.43 mol) was added until the precipitate disappeared. The reaction mixture is allowed to reach room temperature. After cooling again to 0° C., 125 ml of 30% hydrogen peroxide (H2O2) solution was added drop wise with vigorous stirring (light yellow precipitate). This mixture was refluxed for 1.5 hours, then cooled to 0° C. and acidified with 5M HCl. The organic phase was washed with cold 10% sodium sulphite solution and extracted with 2M sodium hydroxide. The combined aqueous extract was acidified, extracted with ethyl acetate and dried on sodium sulfate. Evaporation gave an orange oil which was filtered and isolated by column chromatography eluting with 15% ethyl acetate/hexane, yielding the product dibenzofuran-4-ol as an off-white solid. Yield 44 g (81%) 1H-NMR (300 MHz, CDCl3) 7.95 (d, J=7.5, 1H); 7.60 (d, J=8.4, 1H); 7.53 (dd, J=7.8, 1H); 7.48 (t, J=8.4, 1.2, 1H); 7.36 (t, J=7.5, 1.2, 1H); 7.23 (t, J=7.8, 1H); 7.03 (dd, J=8.1, 1.0, 1H); 5.50 (s, OH)

Workup

  1. temperatureThe mixture was refluxed for 1 hour (yellow precipitate)
  2. customto reach room temperature
  3. temperatureAfter cooling again to 0° C.
  4. stirringwith vigorous stirring (light yellow precipitate)
  5. temperatureThis mixture was refluxed for 1.5 hours
  6. temperaturecooled to 0° C.
  7. washThe organic phase was washed with cold 10% sodium sulphite solution
  8. extractionextracted with 2M sodium hydroxide
  9. extractionThe combined aqueous extract
  10. extractionextracted with ethyl acetate
  11. customdried on sodium sulfate
  12. customEvaporation
  13. customgave an orange oil which
  14. filtrationwas filtered
  15. customisolated by column chromatography
  16. washeluting with 15% ethyl acetate/hexane

Sources & evidence

ORD record
ord-8bff0704d3a049f681f53ed7b8dbd391
Source dataset
uspto-grants-2012_09
Patent number
US08263648B2

Reaction notes

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