反应详情

温度

130 °C

A mixture of the product from step (f) (1.6 g), diethyl carbonate (0.71 g) and potassium carbonate (0.08 g) was heated at 130° C. for 5 hours. The mixture was cooled, taken up in methanol and the insoluble potassium carbonate filtered off. The filtrate was evaporated in vacuo and the residue eluted through a silica column using DCM/EtOH/NH4OH (30:8:1) as eluant to give a colourless foam which was crystallised from isopropanol/ether to give the desired product as a colourless crystalline solid (1.1 g), mp 191°-192° C. 1H NMR and microanalysis as for product of Synthetic Example 4.

1. temperatureThe mixture was cooled
2. filtrationthe insoluble potassium carbonate filtered off
3. customThe filtrate was evaporated in vacuo
4. washthe residue eluted through a silica column
5. customto give a colourless foam which
6. customwas crystallised from isopropanol/ether