Ethanol → HCID 69538822, compound

Participants

Reaction Conditions

Reaction Steps

In a 100 ml flask were charged 2.70 g (9.60 mmol) of the ethyl (S)-4-benzyloxycarbonylamino-3-hydroxybutyrate (optical purity: 94%e.e.) prepared in Reference Example 3, 40 ml of ethanol, and 2.40 g (48.0 mmol) of hydrazine monohydrate in a nitrogen stream, followed by heating under reflux for 20 hours. The reaction mixture was cooled to room temperature (22 to 24° C.), and ethanol was evaporated under reduced pressure. To the residue was added 30 ml of methanol and heat-refluxed to dissolve the crude crystals, followed by cooling to 5° C. After stirring for 1 hour for crystallization, the precipitated crystals were collected by filtration and washed with 10 ml of diethyl ether to afford 1.42 g (52%) of the title compound. Melting point: 135.4° C. Optical purity: >99.9%e.e.

Provenance & Evidence