反应详情

A mixture of 6-hydroxy-2H-1-benzopyran-3-carboxaldehyde (25.0 g, 0.14 mol) and potassium carbonate (39.2 g, 0.28 mol) in 500 ml of DMF is treated with benzyl bromide (26.7 g, 0.16 mol). The mixture is stirred overnight at room temperature. Water is added and three extractions with dichloromethane are carried out. The extract is dried (MgSO4) and evaporated to dryness. The residue is crystallized from hot ethyl acetate to give 6-benzyloxy-2H-1-benzopyran-3-carboxaldehyde, m.p. 112°-114° C.

1. extractionthree extractions with dichloromethane
2. dry with materialThe extract is dried (MgSO4)
3. customevaporated to dryness
4. customThe residue is crystallized from hot ethyl acetate