Hydrochloric Acid → 7-hydroxy-2,3-dihydro-4H-chromen-4-one

HRID 1690706Notes

Reaction equation

HRID 1690706 reaction equation
Cl[CH2:2][CH2:3][C:4]([C:6]1[CH:11]=[CH:10][C:9]([OH:12])=[CH:8][C:7]=1[OH:13])=[O:5].Cl>[OH-].[Na+]>[OH:12][C:9]1[CH:8]=[C:7]2[C:6]([C:4](=[O:5])[CH2:3][CH2:2][O:13]2)=[CH:11][CH:10]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 118057423-Chloro-1-(2,4-dihydroxyphenyl)propan-1-one

Product 1

HCID 108558177-hydroxy-2,3-dihydro-4H-chromen-4-one

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

The crude 3-chloro-1-(2,4-dihydroxy-phenyl)-propan-1-one (6.9 g) is dissolved in sodium hydroxide (2N, 100 mL) at 0° C. The solution is stirred for 2 h and acidified with HCl (5N) to pH=3. The mixture is extracted with ethyl acetate (3×50 mL). The combined organic phase is washed with brine and dried over sodium sulfate. After evaporation of solvent, 7-hydroxy-chroman-4-one is obtained as yellow solid: 1H NMR (400 MHz, MeOD) δ 7.70 (d, 1H, J=8.8 Hz), 6.47 (dd, 1H, J=2.4, 8.8 Hz), 6.30 (d, 1H, J=2.0 Hz), 4.47 (t, 2H, J=6.4 Hz), 2.70 (t, 2H, J=6.4 Hz).

Workup

  1. extractionThe mixture is extracted with ethyl acetate (3×50 mL)
  2. washThe combined organic phase is washed with brine
  3. dry with materialdried over sodium sulfate
  4. customAfter evaporation of solvent

Sources & evidence

ORD record
ord-ddc684379c5b4b2cb0f45d1f71a1cf7d
Source dataset
uspto-grants-2012_04
Patent number
US08153671B2

Reaction notes

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