1,5-Dibromopentane → HCID 19921918, compound

HRID 327943Notes

Reaction equation

HRID 327943 reaction equation
[OH:1][C:2]1[CH:12]=[CH:11][C:5]2[C:6](=[O:10])[CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[CH2:13][CH2:14][CH3:15].[Br:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21]Br.C(=O)([O-])[O-].[K+].[K+]>CC(=O)CC>[Br:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][O:1][C:2]1[CH:12]=[CH:11][C:5]2[C:6](=[O:10])[CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[CH2:13][CH2:14][CH3:15]

Participants

5

Reactant 3

HCID 81001,5-DibromopentaneHCID 11430Potassium CarbonateHCID 153182992,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one

Product 1

HCID 19921918HCID 19921918, compound

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

A mixture of 0.413 g (2.00 mmol) of 2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one, 3.0 g (13.05 mmol) of 1,5-dibromopentane, 1.4 g (10.13 mmol) of anhydrous granular potassium carbonate and 31 mL of 2-butanone was stirred and refluxed for 18 hr. The resulting slurry was filtered with suction and the solids were washed thoroughly with ethyl acetate. The filtrate and washes were combined and concentrated in vacuo and the residue was purified by flash chromatography on 75 g of silica gel, eluting with 4:1 hexane-ethyl acetate giving 0.627 g (88%) of the title compound as a white solid, mp 47°-48° C.

Workup

  1. temperaturerefluxed for 18 hr
  2. filtrationThe resulting slurry was filtered with suction
  3. washthe solids were washed thoroughly with ethyl acetate
  4. concentrationconcentrated in vacuo
  5. customthe residue was purified by flash chromatography on 75 g of silica gel
  6. washeluting with 4:1 hexane-ethyl acetate giving 0.627 g (88%) of the title compound as a white solid, mp 47°-48° C.

Sources & evidence

ORD record
ord-5eba5622883f4d58995c09468dd3c181
Source dataset
uspto-grants-1993_12
Patent number
US05273999

Reaction notes

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