Cyclopentanone → 6-Bromospiro[2H-1-benzopyran-2,1′-cyclopentan]-4(3H)-one

HRID 1786521Notes

Reaction equation

HRID 1786521 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[C:8]([Br:10])[CH:7]=[CH:6][C:5]=1[OH:11])=[O:3].[C:12]1(=O)[CH2:16][CH2:15][CH2:14][CH2:13]1.N1CCCC1>CO>[Br:10][C:8]1[CH:7]=[CH:6][C:5]2[O:11][C:12]3([CH2:16][CH2:15][CH2:14][CH2:13]3)[CH2:1][C:2](=[O:3])[C:4]=2[CH:9]=1

Participants

5

Reactant 3

HCID 8452CyclopentanoneHCID 31268PyrrolidineHCID 959915'-Bromo-2'-hydroxyacetophenone

Product 1

HCID 591678716-Bromospiro[2H-1-benzopyran-2,1′-cyclopentan]-4(3H)-one

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 5-bromo-2-hydroxyacetophenone (31.6 g, 0.1477 mol), cyclopentanone (26 mL, 0.2939 mol) and pyrrolidine (24 mL, 0.288 mol) in methanol (600 mL) was stirred at 25° C. overnight. The mixture was then concentrated to a red oil. Water was added and the solution was adjusted to pH 1 with concentrated hydrochloric acid. The product was extracted with diethylether. The organic layer was evaporated under reduced pressure. The residue was then dissolved in a small volume of methanol. The solution was treated with charcoal, filtered and water was added to the filtrate. The residue was extracted with diethylether. The organic layer was dried over magnesium sulfate and diethylether was evaporated under reduced pressure. The product was used directly in the next step (77%).

Workup

  1. concentrationThe mixture was then concentrated to a red oil
  2. additionWater was added
  3. extractionThe product was extracted with diethylether
  4. customThe organic layer was evaporated under reduced pressure
  5. dissolutionThe residue was then dissolved in a small volume of methanol
  6. additionThe solution was treated with charcoal
  7. filtrationfiltered
  8. additionwater was added to the filtrate
  9. extractionThe residue was extracted with diethylether
  10. dry with materialThe organic layer was dried over magnesium sulfate and diethylether
  11. customwas evaporated under reduced pressure

Sources & evidence

ORD record
ord-acf9316207ca49a4b73f93a9e869c50a
Source dataset
uspto-grants-2009_03
Patent number
US07507761B2

Reaction notes

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