Trifluoroacetic acid → H-Asn-Leu-Ser-Thr-OBzl.TFA

HRID 971582Notes

Reaction equation

HRID 971582 reaction equation
[NH:1](C(OC(C)(C)C)=O)[C@H:2]([C:7]([NH:9][C@H:10]([C:15]([NH:17][C@H:18]([C:21]([NH:23][C@H:24]([C:28]([O:30][CH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)=[O:29])[C@@H:25]([CH3:27])[OH:26])=[O:22])[CH2:19][OH:20])=[O:16])[CH2:11][CH:12]([CH3:14])[CH3:13])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5].[F:45][C:46]([F:51])([F:50])[C:47]([OH:49])=[O:48]>>[NH2:1][C@H:2]([C:7]([NH:9][C@H:10]([C:15]([NH:17][C@H:18]([C:21]([NH:23][C@H:24]([C:28]([O:30][CH2:31][C:32]1[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=1)=[O:29])[C@@H:25]([CH3:27])[OH:26])=[O:22])[CH2:19][OH:20])=[O:16])[CH2:11][CH:12]([CH3:14])[CH3:13])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5].[F:45][C:46]([C:47]([OH:49])=[O:48])([F:51])[F:50]

Participants

3

Reactant 2

HCID 6422Trifluoroacetic acidHCID 131710002BOC-Asn-Leu-Ser-Thr-OBzl

Product 1

HCID 131710006H-Asn-Leu-Ser-Thr-OBzl.TFA

Conditions

Temperature
-10 °C

Procedure

32 g of BOC-Asn-Leu-Ser-Thr-OBzl are dissolved in 192 ml of 90% strength trifluoroacetic acid and the solution left for 45 minutes at 20° C. Thereafter the solution is concentrated to about 40ml, mixed with 400 ml of ether whilst stirring and stirred for about 20 minutes at 35° C. under reflux. The crystal suspension is then cooled to -10° C. and is left to stand overnight at -10° C. The precipitate is filtered off, washed three times with ether and dried in vacuo over sodium hydroxide. Melting point 125°- 127° C.; Rf4 = 0.33 (on silica gel).

Workup

  1. concentrationThereafter the solution is concentrated to about 40ml
  2. additionmixed with 400 ml of ether
  3. stirringstirred for about 20 minutes at 35° C.
  4. temperatureunder reflux
  5. waitis left
  6. waitto stand overnight at -10° C
  7. filtrationThe precipitate is filtered off
  8. washwashed three times with ether
  9. dry with materialdried in vacuo over sodium hydroxide

Sources & evidence

ORD record
ord-7491d57c7d994840bdae46419ef16a91
Source dataset
uspto-grants-1979_07
Patent number
US04159981

Reaction notes

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