Benzyl chloroformate → 4-Benzyl 9-tert-butyl 1-oxa-4,9-diazaspiro[5.5]undecane-4,9-dicarboxylate

HRID 1879646Notes

Reaction equation

HRID 1879646 reaction equation
[O:1]1[C:6]2([CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][CH2:7]2)[CH2:5][NH:4][CH2:3][CH2:2]1.[OH-].[Na+].Cl[C:22]([O:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)=[O:23]>O1CCOCC1>[O:1]1[C:6]2([CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][CH2:7]2)[CH2:5][N:4]([C:22]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)=[O:23])[CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 10387Benzyl chloroformateHCID 14798Sodium HydroxideHCID 53302318tert-Butyl 1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

Product 1

HCID 574826874-Benzyl 9-tert-butyl 1-oxa-4,9-diazaspiro[5.5]undecane-4,9-dicarboxylate

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a mixture of tert-butyl 1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate (5.80 g) and dioxane (100 mL), 1 M aqueous sodium hydroxide (24.9 mL) and benzyl chloroformate (3.55 mL) were added sequentially under ice cooling and stirred at room temperature for 16 hours. The reaction mixture was concentrated under reduced pressure and then extracted with ethyl acetate. The organic layer was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=9:1-1:1) to give 4-benzyl 9-tert-butyl 1-oxa-4,9-diazaspiro[5.5]undecane-4,9-dicarboxylate (8.06 g) as a colorless syrup.

Workup

  1. additionwere added sequentially under ice cooling
  2. concentrationThe reaction mixture was concentrated under reduced pressure
  3. extractionextracted with ethyl acetate
  4. concentrationThe organic layer was concentrated under reduced pressure
  5. customthe residue was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=9:1-1:1)

Sources & evidence

ORD record
ord-493446bf9cad439791337b0fdcf45e47
Source dataset
uspto-grants-2012_11
Patent number
US08318702B2

Reaction notes

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