反应详情

Into a 250 ml 3-neck flask was added 20.0 grams (0.069 mole) of phenyl 1,2,2,6,6-pentamethyl-4-piperidinyl carbonate and 100 mls of methanol. The flask was equipped with a magnetic stirrer, thermometer, reflux condenser and dropping funnel containing 3.8 grams (0.076 mole) of 64% aqueous hydrazine. The hydrazine was added slowly to the stirring methanol solution at room temperature. There was a slight exotherm. The reaction mixture was stirred for 5 hours at room temperature at which point liquid chromatography indicated the reaction was complete. The methanol was stripped off on a rotating evaporator under reduced pressure and the residue was dissolved in 150 ml MtBE. The MtBE solution was washed 3 times with 25 ml portions of 5% NaOH saturated with sodium chloride to remove the phenol that was generated. The MtBE layer was dried over anhydrous MgSO4, filtered and the MtBE stripped off on a rotating evaporator under reduced pressure. The residue was a white solid (m.p. 90°-94° C.) weighing 14.3 grams (90.5% crude yield). Liquid chromatography indicated the product was one component. The infrared spectrum contained a strong carbonyl peak at 1710 cm-1 and a moderate peak at 1625 cm-1.

1. customThe flask was equipped with a magnetic stirrer
2. temperaturethermometer, reflux condenser
3. customThe methanol was stripped off on a rotating evaporator under reduced pressure
4. dissolutionthe residue was dissolved in 150 ml MtBE
5. washThe MtBE solution was washed 3 times with 25 ml portions of 5% NaOH saturated with sodium chloride
6. customto remove the phenol that
7. dry with materialThe MtBE layer was dried over anhydrous MgSO4
8. filtrationfiltered
9. customthe MtBE stripped off on a rotating evaporator under reduced pressure