Hydrazine hydrate (1:1) → HCID 18657915, compound

Participants

Reaction Steps

Hydrazine monohydrate (0.61 ml, 12.6 mmol) was dropwise added to a solution of 3-[(2S,4S)-N-allyloxycarbonyl-4-tritylthiopyrrolidin-2-yl]acrylic acid ethyl ester (1.53 g, 2.9 mmol) in ethanol (7.5 ml) under cooling with ice, and the mixture was stirred at the same temperature for 1.5 hours. The reaction solution was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (Wakogel™ C-300, 2% methanol-chloroform) to obtain (2S,4S)-N-allyloxycarbonyl-2-(3-pyrazolidinon-5-yl)-4-tritylthiopyrrolidine (830 mg, yield: 51.1%). This compound was immediately dissolved in methylene chloride (10 ml). Then, triethylamine (0.24 ml, 1.7 mmol) and allyl chloroformate (0.18 ml 1.7 mmol) were dropwise added thereto under cooling with ice, and the mixture was stirred at the same temperature for 1 hour. The reaction solution was concentrated under reduced pressure, and the residue was extracted with ethyl acetate (50 ml). The organic layer was washed with water and a saturated sodium chloride aqueous solution, then dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (Wakogel™ C-300, 1% methanol-chloroform) to obtain (2S,4S)-N-allyloxycarbonyl-2-(1-allyloxycarbonyl-3-pyrazolidinon-5-yl)-4-tritylthiopyrrolidine (592 mg, yield: 62%).

Provenance & Evidence