Imidazole → 6-Chloro-2,3-dihydro-7-hydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one

HRID 1724615Notes

Reaction equation

HRID 1724615 reaction equation
N1C=CN=C1.[Cl:6][C:7]1[CH:8]=[C:9]2[C:14](=[CH:15][C:16]=1[O:17]C(=O)C)[O:13][CH2:12][CH:11]([C:21]1[CH:26]=[CH:25][C:24]([O:27]C(=O)C)=[CH:23][CH:22]=1)[C:10]2=[O:31]>C(O)C>[Cl:6][C:7]1[CH:8]=[C:9]2[C:14](=[CH:15][C:16]=1[OH:17])[O:13][CH2:12][CH:11]([C:21]1[CH:26]=[CH:25][C:24]([OH:27])=[CH:23][CH:22]=1)[C:10]2=[O:31]

Participants

4

Reactant 2

HCID 795ImidazoleHCID 9842545HCID 9842545, compound

Product 1

HCID 99260276-Chloro-2,3-dihydro-7-hydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-oneYield 802.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Imidazole (0.60 g) was added to a suspension of 6-chloro-4′,7-diacetoxyisoflavan-4-one (0.24 g, 0.06 mmol) in absolute ethanol (5.0 ml) and the mixture was refluxed for 45 min under argon. The solution was concentrated under reduced pressure and distilled water (10 ml) was added to the residue. The mixture was left overnight in the fridge and the resulting precipitate was filtered, washed with water and dried to yield 6-chloro-4′,7-dihydroxyisoflavan-4-one (0.14 g, 75%) as a white powder. 1H NMR (d6-acetone): δ 3.87 (t, 1H, J 7.2 Hz, H3), 4.64 (d, 2H, J 6.2 Hz, H2), 6.59 (s, 1H, H8), 6.78 (d, 2H, J 8.7 Hz, ArH), 7.10 (d, 2H, J 8.7 Hz, ArH), 7.70 (bs, 1H, OH), 7.77 (s, 1H, H5).

Workup

  1. temperaturethe mixture was refluxed for 45 min under argon
  2. concentrationThe solution was concentrated under reduced pressure
  3. distillationdistilled water (10 ml)
  4. additionwas added to the residue
  5. filtrationthe resulting precipitate was filtered
  6. washwashed with water
  7. customdried

Sources & evidence

ORD record
ord-c65eb4a3aa1e43cfa4d65f4bf0d2aef4
Source dataset
uspto-grants-2009_02
Patent number
US07488494B2

Reaction notes

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