Sodium Hydroxide → 7-hydroxy-2,3-dihydro-4H-chromen-4-one

HRID 1506313Notes

Reaction equation

HRID 1506313 reaction equation
[OH-].[Na+].Cl[CH2:4][CH2:5][C:6]([C:8]1[CH:13]=[CH:12][C:11]([OH:14])=[CH:10][C:9]=1[OH:15])=[O:7]>S(=O)(=O)(O)O>[OH:14][C:11]1[CH:10]=[C:9]2[C:8]([C:6](=[O:7])[CH2:5][CH2:4][O:15]2)=[CH:13][CH:12]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 118057423-Chloro-1-(2,4-dihydroxyphenyl)propan-1-one

Product 1

HCID 108558177-hydroxy-2,3-dihydro-4H-chromen-4-oneYield 81%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

To a stirred 2 M solution of sodium hydroxide (500 mL, 1000 mmol) at 5° C. was added 3-chloro-1-(2,4-dihydroxyphenyl)propan-1-one (Preparation 2A, 13.6 g, 67.9 mmol) in one portion. The solution was warmed to room temperature over 2 h, re-cooled to 5° C., and the pH was adjusted to ˜2 with 6 M aqueous sulfuric acid (˜50 mL). An orange precipitant formed which was collected by vacuum filtration and dried under reduced pressure. The filtrate was extracted with ethyl acetate (3×100 mL), washed with brine, and dried over anhydrous sodium sulfate. Concentration under reduced pressure gave an orange solid. The two recovered solids were combined to give 7-hydroxychroman-4-one (9.0 g, 54.8 mmol, 81% yield). LC/MS M+1=165.0; 1H NMR (400 MHz, CDCl3) δ ppm 7.77 (1H, d, J=8.58 Hz), 6.45 (1H, dd, J=8.69, 2.31 Hz), 6.33 (1H, d, J=2.42 Hz), 5.62 (1H, br. s.), 4.33-4.66 (2H, m), and 2.58-2.90 (2H, m).

Workup

  1. temperaturere-cooled to 5° C.
  2. customAn orange precipitant formed which
  3. filtrationwas collected by vacuum filtration
  4. customdried under reduced pressure
  5. extractionThe filtrate was extracted with ethyl acetate (3×100 mL)
  6. washwashed with brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationConcentration under reduced pressure
  9. customgave an orange solid

Sources & evidence

ORD record
ord-885bc1897c2a480c9d9f74894dfb80bd
Source dataset
uspto-grants-2015_12
Patent number
US09216972B2

Reaction notes

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