反应详情

温度

5 °C

Di-tert-butyl [2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-1,3-propanediyl]biscarbamate (144 g) was suspended in ethanol (1.5 L), and hydrazine monohydrate (19.8 ml) was added dropwise to the suspension under cooling on an ice-water bath. The mixture was refluxed for 5 hours, and cooled to 5° C. on an ice-water bath. The precipitate was filtered off, and the filtrate was concentrated under reduced pressure and recrystallized from hexane (500 ml)—ethyl acetate (100 ml) to give di-tert-butyl (2-amino-1,3-propanediyl)biscarbamate (44.1 g) as crystals. The mother liquor (31.3 g), which proved to be satisfactorily pure by thin layer chromatography, was also used for the next reaction.

1. temperatureunder cooling on an ice-water bath
2. temperatureThe mixture was refluxed for 5 hours
3. filtrationThe precipitate was filtered off
4. concentrationthe filtrate was concentrated under reduced pressure
5. customrecrystallized from hexane (500 ml)—ethyl acetate (100 ml)