反应详情

A solution of EXAMPLE 17B (2.0 g, 11 mmol), 1,2-ethanediol (1.0 g, 16 mmol), and p-toluenesulfonic acid monohydrate (10 mg) in benzene (10 mL) was heated under reflux with a Dean-Stark apparatus for 6 hours. After cooling, the mixture was partitioned between ethyl acetate and brine and the organic phase washed with 10% sodium hydroxide solution, water and concentrated. The residue was purified by flash chromatography on silica gel (1:5 ethyl acetate/hexane) to give 2.1 g (80%) of the title compound. MS (DCI): m/z 227 (M+H)+.

1. temperatureunder reflux with a Dean-Stark apparatus for 6 hours
2. temperatureAfter cooling
3. customthe mixture was partitioned between ethyl acetate and brine
4. washthe organic phase washed with 10% sodium hydroxide solution, water
5. concentrationconcentrated
6. customThe residue was purified by flash chromatography on silica gel (1:5 ethyl acetate/hexane)