Piperazin-2-one → 1-Boc-3-(3-oxo-1-piperazinyl)azetidine

HRID 473594

Reaction equation

HRID 473594 reaction equation
[O:1]=[C:2]1[NH:7][CH2:6][CH2:5][NH:4][CH2:3]1.[C:8]([N:15]1[CH2:18][C:17](=O)[CH2:16]1)([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9].[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+]>ClCCCl.CC(O)=O>[C:11]([O:10][C:8]([N:15]1[CH2:18][CH:17]([N:4]2[CH2:5][CH2:6][NH:7][C:2](=[O:1])[CH2:3]2)[CH2:16]1)=[O:9])([CH3:14])([CH3:12])[CH3:13]

Participants

6

Reactant 3

HCID 231360Piperazin-2-oneHCID 15194043-Oxo-azetidine-1-carboxylic acid tert-butyl ester2×HCID 5049666Sodium triacetoxyborohydride2×

Product 1

HCID 596054391-Boc-3-(3-oxo-1-piperazinyl)azetidineYield 68.9%

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 176Acetic AcidSolvent

Procedure

To a mixture of 3-oxopiperazine 4a (490 mg, 4.89 mmol) and N-Boc-azetidin-3-one 1a (922 mg, 5.38 mmol) in 1,2-dichloroethane (10 mL) and HOAc (0.5 mL) was added Na(OAc)3BH (1141, 5.38 mmol). The reaction was stirred at room temperature overnight. Additional 1a (335 mg, 1.96 mmol) and Na(OAc)3BH (415 mg, 1.96 mmol) was added. The reaction was stirred for another 24 h before it was quenched with aq. NaHCO3. The resulting mixture was extracted with CH2Cl2. The organic solution was dried over Na2SO4 and concentrated. Purification by column chromatography (silica gel, 4% MeOH/CH2Cl2) gave intermediate 4b as white solid (860 mg).

Workup

  1. stirringThe reaction was stirred for another 24 h before it
  2. customwas quenched with aq. NaHCO3
  3. extractionThe resulting mixture was extracted with CH2Cl2
  4. dry with materialThe organic solution was dried over Na2SO4
  5. concentrationconcentrated
  6. customPurification by column chromatography (silica gel, 4% MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-6c6a32182fe444da9fcb8db27933f73c
Source dataset
uspto-grants-2014_01
Patent number
US08637498B2

Linked notes

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