Boron trifluoride etherate → 1-Benzyl 4-ethyl 5-oxoazepane-1,4-dicarboxylate

HRID 2361701Notes

Reaction equation

HRID 2361701 reaction equation
[CH2:1]1[N:7]([C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:9])[CH2:6][CH2:5][N+](=O)[CH2:2]1.[N+](=[CH:20][C:21]([O:23][CH2:24][CH3:25])=[O:22])=[N-].B(F)(F)F.C[CH2:31][O:32]CC.C([O-])([O-])=O.[K+].[K+]>C(OCC)C>[O:32]=[C:31]1[CH2:5][CH2:6][N:7]([C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:9])[CH2:1][CH2:2][CH:20]1[C:21]([O:23][CH2:24][CH3:25])=[O:22]

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 11430Potassium CarbonateHCID 12192Ethyl diazoacetateHCID 53420650Benzyl 4-oxo-1-piperazinecarboxylate

Product 1

HCID 146001211-Benzyl 4-ethyl 5-oxoazepane-1,4-dicarboxylateYield 102.7%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a suspension of benzyl 4-oxo-1-piperazinecarboxylate (11.7 g, 50.3 mmol) in diethyl ether (100 ml) at −78° C. was added ethyl diazoacetate (6.84 ml, 65.3 mmol) followed by BF3.OEt2 (6.30 ml, 50.3 mmol). After 1 hour the reaction was raised to room temperature giving a clear yellow solution. A saturated aqueous solution of K2CO3 was added dropwise until no further gas evolution was observed. The organic layer was separated and washed with saturated aqueous K2CO3 (2×50 ml), dried (MgSO4), filtered and concentrated giving the title product as yellow oil (16.5 g, quant. yield). The product was used without further purification.

Workup

  1. customgiving a clear yellow solution
  2. customThe organic layer was separated
  3. washwashed with saturated aqueous K2CO3 (2×50 ml)
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-115fe4e87ae345a6a9ec5db70be2743f
Source dataset
uspto-grants-2014_04
Patent number
US08691804B2

Reaction notes

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