Acetic Anhydride → HCID 86690075, compound

HRID 520353Notes

Reaction equation

HRID 520353 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([C:20]([CH3:24])([CH3:23])[CH2:21][OH:22])[C:10]([O:12][CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:25](OC(=O)C)(=[O:27])[CH3:26]>C(Cl)Cl.CN(C1C=CN=CC=1)C.CCOC(C)=O>[C:25]([O:22][CH2:21][C:20]([CH3:24])([CH3:23])[C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[C:10]([O:12][CH2:13][C:14]1[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1)=[O:11])(=[O:27])[CH3:26]

Participants

6

Reactant 2

HCID 7918Acetic AnhydrideHCID 67407089(S)-benzyl 2-(tert-butoxycarbonylamino)-4-hydroxy-3,3-dimethylbutanoate

Product 1

HCID 86690075HCID 86690075, compoundYield 91.9%

Reagents, catalysts & solvents 3

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of (S)-benzyl 2-(tert-butoxycarbonylamino)-4-hydroxy-3,3-dimethylbutanoate (0.3 g) in DCM (3 mL) was added DMAP (0.109 g, 0.889 mmol) and acetic anhydride (0.084 mL, 0.889 mmol). The reaction mixture was stirred at rt for 16 hrs, then diluted with EtOAc, washed with sat. NaHCO3, water, sat. NaCl, dried over anhydrous Na2SO4, filtered and concentrated to yield an oil. The crude product was purified by silica gel chromatography (0-100% EtOAc in hexane) to yield (S)-benzyl 4-acetoxy-2-(tert-butoxycarbonylamino)-3,3-dimethylbutanoate (0.31 g). LC/MS (Cond. N-1): [M+Na]+ 402.22, RT=3.821 min.

Workup

  1. washwashed with sat. NaHCO3, water, sat. NaCl
  2. dry with materialdried over anhydrous Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customto yield an oil
  6. customThe crude product was purified by silica gel chromatography (0-100% EtOAc in hexane)

Sources & evidence

ORD record
ord-bf90622f6b574d34b9ad3d7570b48c43
Source dataset
uspto-grants-2016_05
Patent number
US09326973B2

Reaction notes

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