Ethanol → (R)-ethyl 2-amino-5-(benzyloxycarbonylamino)pentanoate

HRID 2403250Notes

Reaction equation

HRID 2403250 reaction equation
[NH:1](C(OC(C)(C)C)=O)[C@H:2]([C:17]([OH:19])=[O:18])[CH2:3][CH2:4][CH2:5][NH:6][C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:8].O=S(Cl)Cl.[CH3:31][CH2:32]O>>[NH2:1][C@H:2]([CH2:3][CH2:4][CH2:5][NH:6][C:7]([O:9][CH2:10][C:11]1[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=1)=[O:8])[C:17]([O:19][CH2:31][CH3:32])=[O:18]

Participants

4

Reactant 3

HCID 702EthanolHCID 24386Thionyl ChlorideHCID 7269338(2S)-5-{[(benzyloxy)carbonyl]amino}-2-{[(tert-butoxy)carbonyl]amino}pentanoic acid

Product 1

HCID 86584445(R)-ethyl 2-amino-5-(benzyloxycarbonylamino)pentanoateYield 55%

Conditions

Temperature
-10 °C

Procedure

Boc-Orn(Z)—OH (1 equivalent, 0.4 g, 1.1 mmol) was dissolved in EtOH (4 mL). The reaction mixture was cooled at −10° C., and SOCl2 (1.5 equivalent, 119 μl, 1.65 mmol) was added dropwise. The mixture was allowed to warm to room temperature, then heated at 40° C. for 20 h (TLC control). The reaction mixture was concentrated and the crude was purified by flash chromatography (CH2Cl2/MeOH) to afford the compound 188 (178 mg, 55%) as a white solid Rf=0.23 (CH2Cl2/MeOH 90/10). 1H NMR (300 MHz, CDCl3): δ 7.37-7.27 (m, 5H), 5.54 (broad s, 1H), 5.05 (s, 2H), 4.17 (q, J=6.9 Hz, 2H), 3.95 (broad s, 1H), 3.30-3.13 (m, 2H), 2.10-1.85 (m, 2H), 1.85-1.55 (m, 2H), 1.22 (t, J=7.1 Hz, 3H).

Workup

  1. temperatureto warm to room temperature
  2. temperatureheated at 40° C. for 20 h (TLC control)
  3. concentrationThe reaction mixture was concentrated
  4. customthe crude was purified by flash chromatography (CH2Cl2/MeOH)

Sources & evidence

ORD record
ord-e3d06960b9e744689796a48f668869b2
Source dataset
uspto-grants-2014_08
Patent number
US08802666B2

Reaction notes

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