Hydrochloric Acid → 1-(4,4-Dimethyl-3,4-dihydro-2H-1-benzopyran-6-yl)ethan-1-one

HRID 1769326Notes

Reaction equation

HRID 1769326 reaction equation
[CH3:1][C:2]1([CH3:12])[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5][CH2:4][CH2:3]1.[C:13](Cl)(=[O:15])[CH3:14].[Cl-].[Al+3].[Cl-].[Cl-].Cl>[N+](C)([O-])=O.CCOCC>[CH3:1][C:2]1([CH3:12])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:13](=[O:15])[CH3:14])[CH:10]=2)[O:5][CH2:4][CH2:3]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6367Acetyl chlorideHCID 3167634,4-DimethylchromanHCID 6451240Aluminum(III) Chloride

Product 1

HCID 134781601-(4,4-Dimethyl-3,4-dihydro-2H-1-benzopyran-6-yl)ethan-1-one

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6375NitromethaneSolvent

Procedure

To a stirred solution of 7.94 g (48.9425 mmol) of 4,4-dimethylchroman in 70 ml of nitromethane was added under argon 4.0 g (50.96 mmol) of acetyl chloride followed by 6.8 g (51 mmol) of aluminum chloride. This was stirred at room temperature for 5.5 hours and then cooled in an ice bath and treated slowly with 70 ml 6N hydrogen chloride. The resultant mixture was stirred at room temperature for 10 minutes, then treated with 100 ml ether and the organic layer separated. The organic layer was washed with water, saturated NaHCO3 and saturated NaCl solution and dried (MgSO4). Solvent was removed in vacuo and the residue purified by flash chromatography (silica; 10% ethyl acetate in hexanes). This was followed by kugelrohr distillation (95°-100° C.; 0.15 mm) to give the title compound as a colorless oil.

Workup

  1. temperaturecooled in an ice bath
  2. customthe organic layer separated
  3. washThe organic layer was washed with water, saturated NaHCO3 and saturated NaCl solution
  4. dry with materialdried (MgSO4)
  5. customSolvent was removed in vacuo
  6. customthe residue purified by flash chromatography (silica; 10% ethyl acetate in hexanes)
  7. distillationThis was followed by kugelrohr distillation (95°-100° C.; 0.15 mm)

Sources & evidence

ORD record
ord-cbe1ddb2bd4a41f693c1eb899950a7bd
Source dataset
uspto-grants-1995_01
Patent number
US05380877

Reaction notes

Loading…