Hydrazine hydrate (1:1) → HCID 9882575, compound

Participants

Reaction Steps

To a solution of (2S,4S)-6-fluoro-2',5'-dioxospiro[chroman-4,4'-imidazolidine]-2-carboxylic acid n-propyl ester (30.0 g, 93.1 mmol) in 600 ml of ethanol was added hydrazine hydrate (46.6 g, 0.931 mol). After refluxing the mixture under an argon atmosphere for 2 hours, the reaction mixture was evaporated in vacuo to dryness. To the residue was added 100 ml of saturated aqueous sodium chloride and the aqueous layer was extracted with ethyl acetate (300 ml×5). The combined ethyl acetate layers were washed with water, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to give 17.3 g (Yield: 63.1%) of crude crystals. The crystals were recrystallized from ethanol to give colorless needles of the desired compound (12.8 g, 46.7%).

Provenance & Evidence