反应详情

温度

53 °C

Into a 2 liter round bottom flask equipped with an oil bath, reflux condenser, and nitrogen atmosphere sparger were charged 1,2,2,6,6-pentamethyl-4-piperidinol (51.2 g, 0.3 mole) and 1 liter of 2-butanone. Freshly distilled phosgene (35 ml, 0.45 mole) was evaporated into the reactor in a stream of nitrogen; a solid precipitate formed immediately. The resulting slurry was heated to reflux which initially was 53° C. but rose gradually over 25 minutes to 77° C. during which time the initially formed solid dissolved. After an additional 25 minutes of reflux at 77° C., the reaction mixture was cooled while being purged of excess phosgene and hydrogen chloride with a nitrogen stream. The ketone solvent was stripped from the product using an aspirator vacuum. The solid obtained was isolated and washed with 300 ml of 1,1,1-trichloroethane; then it was washed a second time with 200 ml of 1,1,1-trichloroethane. The resulting white crystalline solid was dried under high vacuum to give 76.5 g of the chloroformate hydrochloride having an assay of 99.7% (by analysis of hydrolyzable chloride: theoretical 26.24%, found 26.17%) and a corrected yield of 94.4%.

1. customInto a 2 liter round bottom flask equipped with an oil bath
2. temperaturereflux condenser
3. customa solid precipitate formed immediately
4. temperatureThe resulting slurry was heated
5. dissolutiondissolved
6. temperatureAfter an additional 25 minutes of reflux at 77° C.
7. temperaturethe reaction mixture was cooled
8. customwhile being purged of excess phosgene and hydrogen chloride with a nitrogen stream
9. customThe solid obtained
10. customwas isolated
11. washwashed with 300 ml of 1,1,1-trichloroethane
12. washthen it was washed a second time with 200 ml of 1,1,1-trichloroethane
13. customThe resulting white crystalline solid was dried under high vacuum