Acetone → 2,2-Dimethyl-chroman-4-one

HRID 1363215Notes

Reaction equation

HRID 1363215 reaction equation
[OH:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8](=[O:10])[CH3:9].[CH3:11][C:12]([CH3:14])=O.N1CCCC1>CO>[CH3:11][C:12]1([CH3:14])[CH2:9][C:8](=[O:10])[C:3]2[C:2](=[CH:7][CH:6]=[CH:5][CH:4]=2)[O:1]1

Participants

5

Reactant 3

HCID 180AcetoneHCID 83752'-HydroxyacetophenoneHCID 31268Pyrrolidine

Product 1

HCID 74542902,2-Dimethyl-chroman-4-one

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 2′-hydroxyacetophenone (5.0 mL), acetone (4.7 mL), and pyrrolidine (5.4 mL) in 150 mL of methanol was stirred for 66 hours. The mixture was concentrated and treated with aqueous HCl (pH<1). The acidic layer was extracted twice with ethyl ether, which was dried and concentrated to provide 2,2-dimethylchroman-4-one. The 2,2-dimethylchroman-4-one was dissolved in 300 mL of methanol and treated with ammonium acetate (65 g) and sodium cyanoborohydride (2.5 g) for 24 hours. The resulting mixture was concentrated to 100 mL and diluted with 300 mL water. Concentrated HCl was carefully added until the pH was less than 1 and the acidic mixture was extracted with ethyl ether. The acidic phase was made basic with KOH and then extracted twice with ethyl ether. The basic extracts were dried and concentrated to provide the title compound.

Workup

  1. concentrationThe mixture was concentrated
  2. additiontreated with aqueous HCl (pH<1)
  3. extractionThe acidic layer was extracted twice with ethyl ether, which
  4. customwas dried
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-49e709f535214350b0f30c6e3303c175
Source dataset
uspto-grants-2011_02
Patent number
US07884109B2

Reaction notes

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