反应详情

The starting material is prepared as follows: A mixture of 6-hydroxy-2H-1-benzopyran-3-carboxaldehyde (4.0 g, 22.7 mmol) and potassium carbonate (6.26 g, 45.3 mmol) in 80 ml of DMF is treated with n-hexyl bromide (4.5 g, 27.2 mmol). The mixture is stirred overnight at room temperature. Additional potassium carbonate (3.1 g, 22.4 mmol) and n-hexyl bromide (1.0 g, 6.1 mmol) are added and, after another overnight reaction, no more starting material is detected in the reaction mixture. The reaction mixture is diluted with water and extracted three times with dichloromethane. The combined organic phases are dried (MgSO4) and evaporated. Purification by silica gel chromatography (10% ethyl acetate/hexane) yields 6-(n-hexyloxy)-2H-1-benzopyran-3-carboxaldehyde, m.p. 36°-38° C., which is converted as described above to 3-(N-hydroxyaminomethyl)-6-(n-hexyloxy)-2H-1-benzopyran.

1. customThe starting material is prepared
2. customreaction
3. extractionextracted three times with dichloromethane
4. dry with materialThe combined organic phases are dried (MgSO4)
5. customevaporated
6. customPurification by silica gel chromatography (10% ethyl acetate/hexane)