Methyl iodide → 2H-1-Benzopyran-2-one, 7-methoxy-4,8-dimethyl-

HRID 1587051Notes

Reaction equation

HRID 1587051 reaction equation
[CH3:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:13])[C:8]([OH:12])=[CH:9][CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1.CI.[C:17](=O)([O-])[O-].[K+].[K+]>CC(C)=O.[OH-].[Na+]>[CH3:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:13])[C:8]([O:12][CH3:17])=[CH:9][CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1

Participants

6

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 53565972H-1-Benzopyran-2-one, 7-hydroxy-4,8-dimethyl-

Product 1

HCID 8795452H-1-Benzopyran-2-one, 7-methoxy-4,8-dimethyl-Yield 66%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 14798Sodium HydroxideSolvent

Procedure

A solution of 4,8-dimethyl-7-hydroxycoumarin (0.190 g, 1.00 mmol) and methyl iodide (0.180 g, 1.30 mmol) in 50 ml of dry acetone was heated at reflux in the presence of 0.5 g of potassium carbonate for 14 hours. The solution was then cooled and filtered. The filtrate was evaporated under reduced pressure to yield a beige solid. The beige solid was taken up in 20% sodium hydroxide (aqueous) and collected by vacuum filtration. The crude product was recrystallized from methanol to yield shiny white crystals, m.p. 162°-164° C., 135 mg, 66% yield. 1H-NMR: 2.27 (s, 3H, C8 --CH3), 2.4 (d, 3H, C4 --CH3, J=1.2 Hz), 3.9 (s, 3H, OCH3), 6.1 (q, 1H, C3 --H, J=1.2 Hz), 6.8-6.9 (d, 1H, C6 --H, J=8.8 Hz), 7.4- 7.5 (d, 1H, C5 --H, J=8.8 Hz).

Workup

  1. temperatureThe solution was then cooled
  2. filtrationfiltered
  3. customThe filtrate was evaporated under reduced pressure
  4. customto yield a beige solid
  5. filtrationcollected by vacuum filtration
  6. customThe crude product was recrystallized from methanol
  7. customto yield shiny white crystals, m.p. 162°-164° C., 135 mg, 66% yield

Sources & evidence

ORD record
ord-a902e2664938405dadc98e63b3ded848
Source dataset
uspto-grants-1993_06
Patent number
US05216176

Reaction notes

Loading…