反应详情

To a stirred solution of the compound prepared in Example 421 (1.88 g) in N,N-dimethylformamide (25 mL) was added N,N-dimethylformamide dimethylacetal (1.61 mL) at room temperature. The resulting purple solution was placed in an oil bath and heating was started to 140° C. The mixture was heated for 30 minutes, cooled to room temperature, the solvent evaporated in vacuo, coevaporated from methanol and dried further under high vacuum for 2 hours. This material was triturated in 1:1 hexane-ether and collected by filtration to afford the title compound as red solids (2.2 g) with the following physical data.

1. customThe resulting purple solution was placed in an oil bath
2. temperatureheating
3. customwas started to 140° C
4. temperatureThe mixture was heated for 30 minutes
5. customthe solvent evaporated in vacuo
6. customdried further under high vacuum for 2 hours
7. customThis material was triturated in 1:1 hexane-ether
8. filtrationcollected by filtration