Boron Trichloride → 5-hydroxy-7-methoxyspiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one

HRID 326307Notes

Reaction equation

HRID 326307 reaction equation
C[O:2][C:3]1[C:8]2[C:9](=[O:18])[CH2:10][C:11]3([O:17][C:7]=2[CH:6]=[C:5]([O:19][CH3:20])[CH:4]=1)[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12]3.B(Cl)(Cl)Cl>ClCCl>[OH:2][C:3]1[C:8]2[C:9](=[O:18])[CH2:10][C:11]3([O:17][C:7]=2[CH:6]=[C:5]([O:19][CH3:20])[CH:4]=1)[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12]3

Participants

4

Reactant 2

HCID 25135Boron TrichlorideHCID 11652005HCID 11652005, compound

Product 1

HCID 197367055-hydroxy-7-methoxyspiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 5,7-dimethoxy-spiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one (prepared in Preparation 8) (0.70 g, 2.54 mmol) in dry dichloromethane (5 ml) is added dropwise 2M boron trichloride solution in dichloromethane (3 ml, 6 mmol) at -35° C. After one hour stirring at -30° to 0° C., ice-cold water is added to the mixture and the mixture is extracted with dichloromethane. The dichloromethane layer is washed with water, dried, and concentrated to yield 5-hydroxy-7-methoxyspiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one as a crude crystalline solid (0.66 g, 99.5%). Recrystallization from hexane gives a product having a melting point of 69°-70° C.

Workup

  1. additionice-cold water is added to the mixture
  2. extractionthe mixture is extracted with dichloromethane
  3. washThe dichloromethane layer is washed with water
  4. customdried
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-11212d9760c6489f91affc47d1832fc4
Source dataset
uspto-grants-1993_12
Patent number
US05268386

Reaction notes

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