Pyridine → 3-(4-Methoxyphenyl)-4-oxo-4H-1-benzopyran-7-yl acetate

HRID 603267Notes

Reaction equation

HRID 603267 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:20])[CH:7]([C:12]3[CH:17]=[CH:16][C:15]([O:18][CH3:19])=[CH:14][CH:13]=3)[CH2:8][O:9]2)=[CH:4][CH:3]=1.[C:21](OC(=O)C)(=[O:23])[CH3:22].N1C=CC=CC=1>O>[C:21]([O:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:20])[C:7]([C:12]3[CH:17]=[CH:16][C:15]([O:18][CH3:19])=[CH:14][CH:13]=3)=[CH:8][O:9]2)=[CH:4][CH:3]=1)(=[O:23])[CH3:22]

Participants

5

Reactant 3

HCID 1049PyridineHCID 7918Acetic AnhydrideHCID 147307962,3-Dihydro-7-hydroxy-3-(4-methoxyphenyl)-4H-1-benzopyran-4-one

Product 1

HCID 9088273-(4-Methoxyphenyl)-4-oxo-4H-1-benzopyran-7-yl acetateYield 91%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 7-hydroxy-4′-methoxyisoflavanone (2.0 g, 7.5 mmol), acetic anhydride (10 ml) and pyridine (2 ml) was heated on an oil bath at 105-110 C. for 1 hour. After cooling the mixture to room temperature, it was poured into water (100 ml), stirred for 2 hours and then extracted with dichloromethane (3×50 ml). The dichloromethane layer was washed with water, dried over anhydrous sodium sulfate and evaporated. The white residue was crystallised from methanol to yield 7-acetoxy-4′-methoxyisoflavone as colourless prisms (2.1 g, 91%). 1H NMR (CDCl3): δ 2.36 (s, 3H, OCOCH3), 3.84 (s, 3H, OCH3), 6.98 (d, 2H, J 8.7 Hz, ArH), 7.16 (dd, 1H, J 1.9 Hz 8.6 Hz, H6), 7.30 (d, 1H, J 1.9 Hz H8), 7.50 (d, 2H, J 8.7 Hz, ArH), 8.00 (s, 1H, H2), 8.32 (d, 1H, J 8.6 Hz, H5).

Workup

  1. temperaturewas heated on an oil bath at 105-110 C
  2. extractionextracted with dichloromethane (3×50 ml)
  3. washThe dichloromethane layer was washed with water
  4. dry with materialdried over anhydrous sodium sulfate
  5. customevaporated
  6. customThe white residue was crystallised from methanol

Sources & evidence

ORD record
ord-63b32716636945beb7694baf0e9d7b9f
Source dataset
uspto-grants-2011_03
Patent number
US07906660B2

Reaction notes

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