Boron tribromide → 9a-butyl-8-chloro-7-hydroxy-4-(trifluoromethyl)-1,2,9,9a-tetrahydro-3H-fluoren-3-one

HRID 7881Notes

Reaction equation

HRID 7881 reaction equation
[CH2:1]([C:5]12[CH2:17][CH2:16][C:15](=[O:18])[C:14]([C:19]([F:22])([F:21])[F:20])=[C:13]1[C:12]1[C:7](=[C:8]([Cl:25])[C:9]([O:23]C)=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4].B(Br)(Br)Br>ClCCl>[CH2:1]([C:5]12[CH2:17][CH2:16][C:15](=[O:18])[C:14]([C:19]([F:21])([F:22])[F:20])=[C:13]1[C:12]1[C:7](=[C:8]([Cl:25])[C:9]([OH:23])=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4]

Participants

4

Reactant 2

HCID 25134Boron tribromide2×HCID 219908969a-butyl-8-chloro-7-methoxy-4-(trifluoromethyl)-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Product 1

HCID 102697909a-butyl-8-chloro-7-hydroxy-4-(trifluoromethyl)-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

A solution of 9a-butyl-8-chloro-7-methoxy-4-(trifluoromethyl)-1,2,9,9a-tetrahydro-3H-fluoren-3-one (32 mg, 0.086 mmol) in anhydrous dichloromethane (0.86 mL) was cooled in a dry ice-acetone bath (−78° C.) and the solution was treated with 1M boron tribromide in dichloromethane (0.258 mL, 0.258 mmol). The cooling bath was removed and the mixture was stirred at room temperature for 95 minutes. Additional 1M BBr3 in CH2Cl2 (0.5 mL, 0.5 mmol) was added and the mixture was stirred at room temperature for an additional 100 minutes. The mixture was partitioned between EtOAc (20 mL) and water (20 mL) containing 2N HCl (3 mL). The organic phase was washed with brine (10 mL), dried over MgSO4, filtered, and evaporated under vacuum. The oily residue was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate, developing with 5% EtOAc in CH2Cl2. The product band was eluted with EtOAc, the eluent evaporated under vacuum, and the residue lyophilized from benzene to afford 9a-butyl-8-chloro-7-hydroxy-4-(trifluoromethyl)-1,2,9,9a-tetrahydro-3H-fluoren-3-one as an amorphous solid.

Workup

  1. customThe cooling bath was removed
  2. stirringthe mixture was stirred at room temperature for an additional 100 minutes
  3. customThe mixture was partitioned between EtOAc (20 mL) and water (20 mL)
  4. additioncontaining 2N HCl (3 mL)
  5. washThe organic phase was washed with brine (10 mL)
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. customevaporated under vacuum
  9. customThe oily residue was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate
  10. washThe product band was eluted with EtOAc
  11. customthe eluent evaporated under vacuum

Sources & evidence

ORD record
ord-2585e949972544e68ec775b4010b196e
Source dataset
uspto-grants-2006_08
Patent number
US07087599B2

Reaction notes

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