Sulfuric Acid → Z-Asn(trt)-OH

HRID 649729Notes

Reaction equation

HRID 649729 reaction equation
OS(O)(=O)=O.[NH:6]([C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16])[C@H:7]([C:12]([OH:14])=[O:13])[CH2:8][C:9](=[O:11])[NH2:10].[C:25](O)([C:38]1[CH:43]=[CH:42][CH:41]=[CH:40][CH:39]=1)([C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1.C(OC(=O)C)(=O)C>C(O)(=O)C.O>[NH:6]([C:15]([O:17][CH2:18][C:19]1[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=1)=[O:16])[C@H:7]([C:12]([OH:14])=[O:13])[CH2:8][C:9](=[O:11])[NH:10][C:25]([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)([C:38]1[CH:39]=[CH:40][CH:41]=[CH:42][CH:43]=1)[C:32]1[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=1

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 6457TriphenylcarbinolHCID 7918Acetic AnhydrideHCID 75314Benzyloxycarbonyl-asparagine

Product 1

HCID 15138256Z-Asn(trt)-OHYield 68%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

Concentrated H2SO4 (0.2 ml) was added to a solution of Cbz-Asn-OH (10 g, 37.6 mmol), trityl alcohol (20 g, 75.2 mmol), and acetic anhydride (7.1 ml, 75.2 mmol) in acetic acid (114 ml) and the reaction was stirred for 1 hour at 50° C. The solution was cooled and slowly added to 1.0 L of cold H2O. The white precipitate was filtered, dissolved in EthOAc (250 ml), washed with H2O, dried over Na2SO4 and filtered. The resulting white solid was crystallized from EthOAc/hexane to give 13 g (68%) of a white solid.

Workup

  1. temperatureThe solution was cooled
  2. filtrationThe white precipitate was filtered
  3. dissolutiondissolved in EthOAc (250 ml)
  4. washwashed with H2O
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. customThe resulting white solid was crystallized from EthOAc/hexane

Sources & evidence

ORD record
ord-56765076c0cc41aaa922f19fc43393f4
Source dataset
uspto-grants-2001_08
Patent number
US06270957B1

Reaction notes

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