Nitrogen → Z-Thr(tBu)-OtBu

HRID 2260762Notes

Reaction equation

HRID 2260762 reaction equation
[NH:1]([C:9]([O:11][CH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:10])[C@H:2]([C:6]([OH:8])=[O:7])[C@@H:3]([CH3:5])[OH:4].S(=O)(=O)(O)O.[CH2:24]=[C:25]([CH3:27])[CH3:26].N#N>ClCCl.C(Cl)(Cl)Cl.CCCCCC>[NH:1]([C:9]([O:11][CH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:10])[C@H:2]([C:6]([O:8][C:13]([CH3:18])([CH3:14])[CH3:12])=[O:7])[C@@H:3]([CH3:5])[O:4][C:25]([CH3:27])([CH3:26])[CH3:24]

Participants

8

Reactant 4

HCID 947NitrogenHCID 1118Sulfuric AcidHCID 8255IsobutyleneHCID 88217N-((Benzyloxy)carbonyl)-L-threonine

Product 1

HCID 72698559Z-Thr(tBu)-OtBu

Reagents, catalysts & solvents 3

HCID 6212ChloroformSolventHCID 6344DichloromethaneSolventHCID 8058HexaneSolvent

Conditions

Temperature
20 °C

Procedure

Z-Thr-OH (25.3 g, 0. 1 mol, Peptide Research Laboratories, Japan) was suspended in dichloromethane (250 ml), to which was added conc. sulfuric acid (1 ml). The mixture was cooled on a dry ice-acetone bath, to which was blown isobutene (the volume increased by 200 ml). The vessel was closed tightly, and the mixture was stirred for 2 days at 20° C. The vessel was opened, into which was blown N2 at 20° C. to purge isobutene, followed by addition of water. The mixture was neutralized with a 10% (W/V) aqueous solution of sodium hydrogencarbonate, which was subjected to extraction twice with dichloromethane. The dichloromethane layer was dried over anhydrous sodium sulfate, then the solvent was distilled off. The residue was purified by means of a silica gel column chromatography (n-hexane:chloroform =1:2) to give an oily product. The yield was 26.6 g (72.7%). Rf: 0.21 (n-hexane:chloroform =1:2) FAB-MS (M+H+)=366 (Theoretical value =366)

Workup

  1. temperatureThe mixture was cooled on a dry ice-acetone bath, to which
  2. temperatureincreased by 200 ml)
  3. customThe vessel was closed tightly
  4. customat 20° C.
  5. customto purge isobutene
  6. additionfollowed by addition of water
  7. extractionwas subjected to extraction twice with dichloromethane
  8. dry with materialThe dichloromethane layer was dried over anhydrous sodium sulfate
  9. distillationthe solvent was distilled off
  10. customThe residue was purified by means of a silica gel column chromatography (n-hexane:chloroform =1:2)
  11. customto give an oily product

Sources & evidence

ORD record
ord-91fb7d45e2dd4becbc4f2147baef1240
Source dataset
uspto-grants-1995_12
Patent number
US05478809

Reaction notes

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