反应详情

A suspension of the product of step i) (18 g), paraformaldehyde (14 g) and zinc dichloride (14 g) in dichloromethane (700 mL) was stirred at room temperature. Hydrogen chloride gas was bubbled through the reaction for 30 minutes. The reaction was stirred at room temperature under a blanket of nitrogen for a further 18 hours. Water (150 mL) was added and the phases separated. The organic phase was dried using magnesium sulfate and concentrated in vacuo to give a green oil which was purified (SiO2 eluting with 30% i-hexane in dichloromethane) to give the sub-title compound (12 g).

1. customHydrogen chloride gas was bubbled through the reaction for 30 minutes
2. stirringThe reaction was stirred at room temperature under a blanket of nitrogen for a further 18 hours
3. additionWater (150 mL) was added
4. customthe phases separated
5. customThe organic phase was dried
6. concentrationconcentrated in vacuo
7. customto give a green oil which
8. customwas purified (SiO2 eluting with 30% i-hexane in dichloromethane)