Boron Trichloride → 7-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyran

HRID 254889Notes

Reaction equation

HRID 254889 reaction equation
C([O:8][C:9]1[CH:26]=[CH:25][C:12]2[CH:13]=[C:14]([C:17]3[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[CH:19][CH:18]=3)[CH2:15][O:16][C:11]=2[CH:10]=1)C1C=CC=CC=1.B(Cl)(Cl)Cl>C(Cl)Cl>[OH:8][C:9]1[CH:26]=[CH:25][C:12]2[CH:13]=[C:14]([C:17]3[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[CH:19][CH:18]=3)[CH2:15][O:16][C:11]=2[CH:10]=1

Participants

4

Reactant 2

HCID 25135Boron TrichlorideHCID 595921047-benzyloxy-3-(4-methoxyphenyl)-2H-1-benzopyran

Product 1

HCID 98598477-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyranYield 81.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of compound 1 (0.2 g, 0.58 mmol) in dry CH2Cl2 (4 mL), a solution of BCl3 (1 M, 0.7 mL, 0.7 mmol) in CH2Cl2 was added dropwise at 0° C. under nitrogen. After stirring for 10 min, the mixture was quenched with ice water and a saturated NaHCO3 solution (10 mL), and then stirred for a further 20 min. After extraction with CH2Cl2 (15 mL×6), the organic layers were combined, washed with brine, and dried with anhydrous MgSO4. After filtration, the filtrate was concentrated in vacuo, followed by purification via silica gel column chromatography (ethyl acetate/n-hexane=1:4), thus giving the title compound 2b as a colorless crystal (0.12 g, 81% yield).

Workup

  1. customthe mixture was quenched with ice water
  2. stirringa saturated NaHCO3 solution (10 mL), and then stirred for a further 20 min
  3. extractionAfter extraction with CH2Cl2 (15 mL×6)
  4. washwashed with brine
  5. dry with materialdried with anhydrous MgSO4
  6. filtrationAfter filtration
  7. concentrationthe filtrate was concentrated in vacuo
  8. customfollowed by purification via silica gel column chromatography (ethyl acetate/n-hexane=1:4)

Sources & evidence

ORD record
ord-d1301a8728c140e49e52e2ee57fbce65
Source dataset
uspto-grants-2011_01
Patent number
US07875735B2

Reaction notes

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