Water → 2,2-Dimethyl-6-acetylchroman

HRID 129182

Reaction equation

HRID 129182 reaction equation
[CH3:1][C:2]([C:4]1[CH:5]=[CH:6][C:7]([OH:10])=[CH:8][CH:9]=1)=[O:3].Cl[C:12]([CH3:16])([CH3:15])[C:13]#[CH:14].O.[OH-].[Na+]>C(Cl)Cl.CO>[C:2]([C:4]1[CH:5]=[CH:6][C:7]2[O:10][C:12]([CH3:16])([CH3:15])[CH2:13][CH2:14][C:8]=2[CH:9]=1)(=[O:3])[CH3:1]

Participants

7

Reactant 4

HCID 962WaterHCID 74694'-HydroxyacetophenoneHCID 14798Sodium HydroxideHCID 706791-Butyne, 3-chloro-3-methyl-

Product 1

HCID 1820772,2-Dimethyl-6-acetylchromanYield 34.3%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of 95% 4-hydroxyacetophenone (13.6 g, 100 mmol), 3-chloro-3-methyl butyne (17.4 g, 170 mmol) in methylene chloride (75 ml) was added water (75 ml), sodium hydroxide (6.4 g, 160 mmol), and Triton B (40% in methanol, 23.0 g, 52 mmol). The reaction mixture was stirred at room temperature for six days. The organic layer was separated, the aqueous phase was reextracted with methylene chloride (2×200 ml). The combined extracts were concentrated in vacuo, the residue was taken up in ethyl acetate (500 ml) washed with 1N sodium hydroxide (3×250 ml), brine (200 ml) and dried over magnesium sulfate. The solvent was evaporated in vacuo and the residue was dissolved in 1,2-dichlorobenzene (40 ml) and heated at reflux temperature for four hours. The solvent was removed by distillation at atmospheric pressure using a vigreaux column and the residue was distilled under reduced pressure (b.p. 140°-150° C. at 2.0 mm) to provide the title A compound (7.0 g) as a light yellow solid. 1H NMR (CDCl3) δ7.75 (dd, J=2.3 & 8.8 Hz, 1H), 7.73 (d, J=2.4 Hz, 1H), 6.78 (d, J=8.8 Hz, 1H), 6.35 (d, J=10.0 Hz, 1H), 5.66 (d, J=9.9 Hz, 1H), 2.53 (s, 3H), 1.45 (s, 6H); 13C NMR (CDCl3) δ196.7, 157.4, 131.1, 130.2, 126.8, 121.6, 120.6, 116.0, 77.5, 28.3, 26.2.

Workup

  1. customThe organic layer was separated
  2. concentrationThe combined extracts were concentrated in vacuo
  3. washwashed with 1N sodium hydroxide (3×250 ml), brine (200 ml)
  4. dry with materialdried over magnesium sulfate
  5. customThe solvent was evaporated in vacuo
  6. dissolutionthe residue was dissolved in 1,2-dichlorobenzene (40 ml)
  7. temperatureheated
  8. temperatureat reflux temperature for four hours
  9. customThe solvent was removed by distillation at atmospheric pressure
  10. distillationthe residue was distilled under reduced pressure (b.p. 140°-150° C. at 2.0 mm)

Sources & evidence

ORD record
ord-3afc93397de04db9a4d83a1713cb1cf5
Source dataset
uspto-grants-1995_11
Patent number
US05466817

Linked notes

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