Acetic Acid → p-Nitrobenzyl 2-(4-tert-butylthio-2-oxo-1-azetidinyl)-4,4-dimethyl-3-oxopentanoate

HRID 2371893Notes

Reaction equation

HRID 2371893 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[C:11]([S:15][CH:16]1[N:19]([CH2:20][C:21]([O:23][CH2:24][C:25]2[CH:30]=[CH:29][C:28]([N+:31]([O-:33])=[O:32])=[CH:27][CH:26]=2)=[O:22])[C:18](=[O:34])[CH2:17]1)([CH3:14])([CH3:13])[CH3:12].[C:35](Cl)(=[O:40])[C:36]([CH3:39])([CH3:38])[CH3:37].C(O)(=O)C>C1COCC1.C1(C)C=CC=CC=1>[C:11]([S:15][CH:16]1[N:19]([CH:20]([C:35](=[O:40])[C:36]([CH3:39])([CH3:38])[CH3:37])[C:21]([O:23][CH2:24][C:25]2[CH:26]=[CH:27][C:28]([N+:31]([O-:33])=[O:32])=[CH:29][CH:30]=2)=[O:22])[C:18](=[O:34])[CH2:17]1)([CH3:14])([CH3:12])[CH3:13]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 62493Pivaloyl chlorideHCID 2733832Lithium HexamethyldisilazideHCID 14460289p-Nitrobenzyl (4-tert-butylthio-2-oxo-1-azetidinyl)acetate

Product 1

HCID 14460290p-Nitrobenzyl 2-(4-tert-butylthio-2-oxo-1-azetidinyl)-4,4-dimethyl-3-oxopentanoateYield 60.7%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent3×

Procedure

6 ml of a freshly prepared 1M solution of lithium bis-trimethysilylamide in THF are added dropwise to a solution of 1059 mg (3 mmol) of p-nitrobenzyl (4-tert-butylthio-2-oxo-1-azetidinyl)acetate in 7 ml of dry THF at -70° C., and a solution of 382 mg of pivaloyl chloride in 1 ml of THF is subsequently added dropwise at -70° C., and the reaction mixture is then stirred for 30 minutes at the same temperature. The mixture is diluted with 200 ml of toluene and a little aqueous acetic acid is added. The organic phase is washed with 100 ml of 2N aqueous hydrochloric acid and twice with saturated sodium chloride solution (100 ml), the organic phase is dried using MgSO4, and the solvent is evaporated in vacuo to give a dark red oil. Purification of the crude product over 40 g of silica gel using toluene: ethyl acetate (9:1) gives 795 mg of a non-crystalline solid. IR spectrum in methylene chloride: 2970, 1770, 1760, 1715, 1610, 1530, 1370, 1350, 1315, 1180, 995, 845 cm-1.

Workup

  1. washThe organic phase is washed with 100 ml of 2N aqueous hydrochloric acid and twice with saturated sodium chloride solution (100 ml)
  2. customthe organic phase is dried
  3. customthe solvent is evaporated in vacuo
  4. customto give a dark red oil
  5. customPurification of the crude product over 40 g of silica gel

Sources & evidence

ORD record
ord-905ed67966644f07adbc84389e4c4439
Source dataset
uspto-grants-1992_03
Patent number
US05096899

Reaction notes

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