反应详情

温度

121 °C

First, 11.2 g (107 mmol) of 2-chloro-2-butenal and 8.35 g (50.0 mmol) of benzenesulfonyl cyanide were introduced to the same reaction vessel as in Example 1. Toluene (15 ml) as the solvent and butanol (1.5 ml) were added, and 1.30 g (5.65 mmol) of tributyl borate was added. Then the mixture was heated under reflux for 7 hours while agitating at an internal temperature of 121° C. in a nitrogen atmosphere, separating and removing water that was produced. After this solution was cooled to room temperature, the low-boiling components, such as solvent, etc., were removed under reduced pressure and the resulting concentrate was cooled in an ice bath to precipitate crystals. The crystals were filtered with a glass filter and washed with 10 ml toluene that had been cooled to 5° C. or lower. Then the crystals were dried for 2 hours in vacuo to give 8.87 g of 2-benzenesulfonyl-5-chloropyridine with the following properties as colorless crystals (purity of 98%, yield of 69% based on benzenesulfonyl cyanide).

1. temperatureThen the mixture was heated
2. temperatureunder reflux for 7 hours
3. customseparating
4. customremoving water that
5. customwas produced
6. temperatureAfter this solution was cooled to room temperature
7. customthe low-boiling components, such as solvent, etc., were removed under reduced pressure
8. concentrationthe resulting concentrate
9. temperaturewas cooled in an ice bath
10. customto precipitate crystals
11. filtrationThe crystals were filtered with a glass
12. filtrationfilter
13. washwashed with 10 ml toluene that
14. temperaturehad been cooled to 5° C.
15. customThen the crystals were dried for 2 hours in vacuo