反应详情

Methyl iodide (145 g; 64.2 ml) in dry ether (50 ml) was added dropwise with stirring to magnesium turnings (22 g) in dry ether (730 ml). After the initial reaction had ceased the reaction mixture was refluxed for 1/2 hour, cooled and 2,3-dihydro-7-methoxy-4-oxo-4H-1-benzopyran, (77.9 g) in dry ether (440 ml) was added dropwise with stirring. After addition the reaction mixture was refluxed for 1 hour, cooled and the complex was decomposed by the addition of ammonium chloride solution. The ethereal layer was separated, washed with water and dried. Evaporation of the solvent left 76 g of the title compound as an oil (89%). MS and NMR analysis were correct for the required compound.

1. customAfter the initial reaction
2. temperaturewas refluxed for 1/2 hour
3. temperaturecooled
4. additionAfter addition the reaction mixture
5. temperaturewas refluxed for 1 hour
6. temperaturecooled
7. customThe ethereal layer was separated
8. washwashed with water
9. customdried
10. customEvaporation of the solvent
11. waitleft 76 g of the title compound as an oil (89%)