Boron tribromide → 8-Hydroxy-6H-11-oxa-6-aza-benzo[a]fluoren-5-one

HRID 915828Notes

Reaction equation

HRID 915828 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:13](=[CH:14][CH:15]=1)[O:12][C:11]1[C:10]3[CH:16]=[CH:17][CH:18]=[CH:19][C:9]=3[C:8](=[O:20])[NH:7][C:6]2=1.B(Br)(Br)Br>O>[OH:2][C:3]1[CH:4]=[C:5]2[C:13](=[CH:14][CH:15]=1)[O:12][C:11]1[C:10]3[CH:16]=[CH:17][CH:18]=[CH:19][C:9]=3[C:8](=[O:20])[NH:7][C:6]2=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 116375298-Methoxy-6H-11-oxa-6-aza-benzo[a]fluoren-5-one

Product 1

HCID 222909858-Hydroxy-6H-11-oxa-6-aza-benzo[a]fluoren-5-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

8-Methoxy-6H-11-oxa-6-aza-benzo[a]fluoren-5-one (22a) (5.0 g) was cooled using an ice bath, and boron tribromide (1 M in methylene chloride, 95 mL, 95 mmol, 5 eq.) added in a steady stream under nitrogen. The reaction was heated at reflux under inert atmosphere for two hours, then cooled to room temperature and poured into water (150 mL). The resulting suspension was allowed to stir for 1 h, filtered, and the solids were washed with water (2×200 mL). The solids were then diluted with 5 N sodium hydroxide (600 mL) using heating. The resulting solution was cooled to 0° C. using an ice bath and the solution was acidified to pH 1 using conc. HCl. The resulting precipitate was vacuum filtered, and the solids washed sequentially with water (3×300 mL) and diethyl ether (300 mL) then dried overnight using a vacuum oven at 50° C. to provide Compound 23a as a gray solid. Yield=4.74 g (100%).

Workup

  1. temperatureThe reaction was heated
  2. temperatureat reflux under inert atmosphere for two hours
  3. filtrationfiltered
  4. washthe solids were washed with water (2×200 mL)
  5. additionThe solids were then diluted with 5 N sodium hydroxide (600 mL)
  6. temperatureusing heating
  7. temperatureThe resulting solution was cooled to 0° C.
  8. filtrationfiltered
  9. washthe solids washed sequentially with water (3×300 mL) and diethyl ether (300 mL)
  10. customthen dried overnight
  11. customat 50° C.

Sources & evidence

ORD record
ord-2a831fbff84147ecad878ddf49038f91
Source dataset
uspto-grants-2007_09
Patent number
US07268143B2

Reaction notes

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