反应详情

A mixture of methyl 5-hydroxybenzofuran-2-carboxylate (4.14 g), potassium carbonate (5.95 g) and allyl bromide (3.73 ml) in dry acetone (100 ml) was refluxed and stirred for 16 hours. The solvent was evaporated and the residue was partitioned between water and ether. The ether was washed with water, dried and evaporated to give methyl 5-(prop-2-enyloxy)benzofuran-2-carboxylate (4.7 g) as a solid, characterised by NMR and mass spectral data. This ester (3.74 g) in N-methylpyrrolidinone (30 ml) was refluxed under nitrogen for 2 hr, cooled, and partitioned between water and ethyl acetate. The organic phase was washed with water, dried and evaporated to give the title ester (3.5 g), mp 114°-119°.

1. temperaturecooled
2. custompartitioned between water and ethyl acetate
3. washThe organic phase was washed with water
4. customdried
5. customevaporated