L-Valine → N-(tert-Butoxycarbonyl)-L-valyl-L-valine

HRID 1764778Notes

Reaction equation

HRID 1764778 reaction equation
[NH:1]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[C@H:2]([C:6]([O:8]N1C(=O)CCC1=O)=O)[CH:3]([CH3:5])[CH3:4].[NH2:23][C@H:24]([C:28]([OH:30])=[O:29])[CH:25]([CH3:27])[CH3:26].CCN(CC)CC>CN(C=O)C>[NH:1]([C:16]([O:18][C:19]([CH3:20])([CH3:21])[CH3:22])=[O:17])[C@H:2]([C:6]([NH:23][C@H:24]([C:28]([OH:30])=[O:29])[CH:25]([CH3:27])[CH3:26])=[O:8])[CH:3]([CH3:4])[CH3:5]

Participants

5

Reactant 3

HCID 6287L-ValineHCID 8471Triethylamine2×HCID 98768Boc-Val-osu

Product 1

HCID 7019900N-(tert-Butoxycarbonyl)-L-valyl-L-valine

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

Boc-Val-OSu (12.6 g, 40 mmol) and H-Val-OH (4.68 g, 40 mmol) were condensed in DMF (250 ml) for 96 hours in the presence of 2 ml Et3N. More Et3N was added when needed to maintain the reaction slightly basic. The remaining insoluble material was filtered off and the filtrate evaporated to dryness (45°). The residue was partitioned between ether and dilute H2SO4 (~1%) and the organic layer washed with water (3×), dried over Na2SO4 and evaporated to a foamy glass. The product was crystallized from ether and petroleum ether: Yield, 12.2 g (96.4 %); mp 155°-158°; [α]D25 = +1.10° (c 1, DMF.

Workup

  1. temperatureto maintain
  2. customthe reaction slightly basic
  3. filtrationThe remaining insoluble material was filtered off
  4. customthe filtrate evaporated to dryness (45°)
  5. customThe residue was partitioned between ether and dilute H2SO4 (~1%)
  6. washthe organic layer washed with water (3×)
  7. dry with materialdried over Na2SO4
  8. customevaporated to a foamy glass
  9. customThe product was crystallized from ether and petroleum ether
  10. customYield

Sources & evidence

ORD record
ord-fa32e6e9812246cd8cd57146dd36d529
Source dataset
uspto-grants-1978_09
Patent number
US04116951

Reaction notes

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