Kojic Acid → Chlorokojic acid

HRID 1928669Notes

Reaction equation

HRID 1928669 reaction equation
[CH:1]1[C:6](=[O:7])[C:5]([OH:8])=[CH:4][O:3][C:2]=1[CH2:9]O.S(Cl)([Cl:13])=O>>[Cl:13][CH2:9][C:2]1[O:3][CH:4]=[C:5]([OH:8])[C:6](=[O:7])[CH:1]=1

Participants

3

Reactant 2

HCID 3840Kojic AcidHCID 24386Thionyl Chloride

Product 1

HCID 82051Chlorokojic acidYield 90%

Procedure

Kojic Acid (50.0 g; 352 mmol)—an inhibitor of tyrosinase with an EC50 of 17.0 μM—was carefully added in portions over 30 min to a stirring solution of thionyl chloride (150 mL) containing hexanes (100 mL). After an additional 3.5 hours of stirring, the product was collected by Büchner filtration and washed with hexanes (2×50 mL). The light yellow solid was dried over night under vacuum to afford chloro-kojic acid (50.9 g; 90% yield). Chloro-kojic acid was found to be a more potent inhibitor of tyrosinase than kojic acid with an EC50 of 6.8 μM. 1H NMR (DMSO-d6) δ 9.30 (br s, 1H; 5-OH); 8.12 (s, 1H; 6-H); 6.56 (s, 1H; 3-H); 4.66 (s, 2H; 2-CH2Cl).

Workup

  1. filtrationthe product was collected by Büchner filtration
  2. washwashed with hexanes (2×50 mL)
  3. customThe light yellow solid was dried over night under vacuum

Sources & evidence

ORD record
ord-ee9d4de0a42c4445baad125e6c72e46b
Source dataset
uspto-grants-2012_05
Patent number
US08183398B2

Reaction notes

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