Hydrazine hydrate (1:1) → tert-butyl N-(2-amino-3-{[(tert-butoxy)carbonyl]amino}propyl)carbamate

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence