Dicyclohexylcarbodiimide → Boc-Asp(OtBu)-OSu

HRID 426963Notes

Reaction equation

HRID 426963 reaction equation
[CH3:1][C:2]([O:5][C:6]([CH2:8][C@H:9]([NH:13][C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C:10]([OH:12])=[O:11])=[O:7])([CH3:4])[CH3:3].O[N:22]1[C:26](=[O:27])[CH2:25][CH2:24][C:23]1=[O:28].C1CCC(N=C=NC2CCCCC2)CC1>O1CCOCC1>[CH3:4][C:2]([O:5][C:6]([CH2:8][C@H:9]([NH:13][C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C:10]([O:12][N:22]1[C:26](=[O:27])[CH2:25][CH2:24][C:23]1=[O:28])=[O:11])=[O:7])([CH3:1])[CH3:3]

Participants

5

Reactant 3

HCID 10868DicyclohexylcarbodiimideHCID 80170N-HydroxysuccinimideHCID 70106364-(1,1-Dimethylethyl) hydrogen N-[(1,1-dimethylethoxy)carbonyl]-L-aspartate

Product 1

HCID 13178396Boc-Asp(OtBu)-OSu

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

The resulting 11.45 g (39.7 mmoles) of oily BOC--Asp(OtBu)--OH and 4.6 g (40 mmoles) of N-hydroxy-succinimide are dissolved in 100 ml of dry dioxane. The solution is cooled until freezing, and then 8.25 g (40 mmoles) of DCC are added. The reaction mixture is stirred at room temperature overnight, the separated DCU is filtered off, and the filtrate is evaporated. The oily residue is solidified with a mixture of n-hexane and diisopropyl ether. The resulting crude product, weighing 13.8 and melting at 98°-102° C., is recrystallized from a threefold amount of isopropanol. 12.1 g (78.3%) of white, crystalline BOC--Asp (OtBu)--OSu are obtained; m.p.: 103°-105° C., [α]D : -25.6° (c: 1.0, in dioxane).

Workup

  1. temperatureThe solution is cooled
  2. filtrationthe separated DCU is filtered off
  3. customthe filtrate is evaporated
  4. additionThe oily residue is solidified with a mixture of n-hexane and diisopropyl ether
  5. customis recrystallized from a threefold amount of isopropanol

Sources & evidence

ORD record
ord-f6c50e0635f44b7abef2dbbed21fc389
Source dataset
uspto-grants-1979_10
Patent number
US04172130

Reaction notes

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