反应详情

Thionyl chloride (6.54 g, 54.9 mmol) in dichloromethane (7 mL) was added dropwise over 30 minutes to a mixture of 1-methyl hydrogen bromobutanedioate (i.e. the product of Step A) (10 g, 47.4 mmol) and N,N-dimethylformamide (5 drops) in dichloromethane (20 mL) heated at reflux. The mixture was heated at reflux for an additional 60 minutes and then allowed to cool to room temperature. The solvent was removed under reduced pressure to leave the title product as an oil (11 g, about 100% yield).

1. temperatureheated
2. temperatureat reflux
3. temperatureThe mixture was heated
4. temperatureat reflux for an additional 60 minutes
5. customThe solvent was removed under reduced pressure