反应详情

A mixture of 6-bromo-pyridine-3-carbaldehyde (8.0 g, 43 mmol) described in Manufacturing Example 210-1-1, ethylene glycol (5.3 g, 86 mmol), p-toluenesulfonic acid (820 mg, 4.3 mmol), and toluene (110 mL) was stirred for 40 minutes under reflux. (The water produced in this reaction was removed with a Dean-Stark trap.) The reaction solution was concentrated under a reduced pressure, and the residue was partitioned into ethyl acetate and water. The organic layer was separated and passed through a glass filter provided with NH silica gel (eluted with ethyl acetate). The eluate was concentrated under a reduced pressure, and the residue was purified by silica gel column chromatography (heptane:ethyl acetate=8:1) to obtain the title compound (5.8 g, 59%).

1. temperatureunder reflux
2. customwas removed with a Dean-Stark trap
3. concentration) The reaction solution was concentrated under a reduced pressure
4. customthe residue was partitioned into ethyl acetate and water
5. customThe organic layer was separated
6. filtrationfilter
7. customprovided with NH silica gel (eluted with ethyl acetate)
8. concentrationThe eluate was concentrated under a reduced pressure
9. customthe residue was purified by silica gel column chromatography (heptane:ethyl acetate=8:1)