Ethanol → HCID 69538822, compound

HRID 2186491Notes

Reaction equation

HRID 2186491 reaction equation
[CH2:1]([O:8][C:9]([NH:11][CH2:12][C@@H:13]([OH:20])[CH2:14]C(OCC)=O)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.[NH2:22][NH2:23].[CH2:24]([OH:26])C>>[CH2:1]([O:8][C:9]([NH:11][C@@H:12]([CH:13]([OH:20])[CH3:14])[C:24]([NH:22][NH2:23])=[O:26])=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 3

HCID 702Ethanol2×HCID 24654Hydrazine hydrate (1:1)HCID 11822048HCID 11822048, compound

Product 1

HCID 69538822HCID 69538822, compoundYield 52%

Conditions

Temperature
5 °C

Procedure

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.

Workup

  1. temperatureby heating
  2. temperatureunder reflux for 20 hours
  3. customwas evaporated under reduced pressure
  4. additionTo the residue was added 30 ml of methanol
  5. temperatureheat-refluxed
  6. dissolutionto dissolve the crude crystals
  7. filtrationthe precipitated crystals were collected by filtration
  8. washwashed with 10 ml of diethyl ether

Sources & evidence

ORD record
ord-13d2f5c40bec493c99501219a07131bb
Source dataset
uspto-grants-2002_06
Patent number
US06403804B1

Reaction notes

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