Acetaldehyde → Tert-butyl 8-ethyl-9-phenyl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate

HRID 712978Notes

Reaction equation

HRID 712978 reaction equation
[C:1]1([CH:7]2[CH2:24][O:23][C:10]3([CH2:15][CH2:14][N:13]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:12][CH2:11]3)[CH2:9][NH:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH:25](=O)[CH3:26].C([BH3-])#N.[Na+]>C(O)C>[CH2:25]([N:8]1[CH:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[CH2:24][O:23][C:10]2([CH2:11][CH2:12][N:13]([C:16]([O:18][C:19]([CH3:20])([CH3:21])[CH3:22])=[O:17])[CH2:14][CH2:15]2)[CH2:9]1)[CH3:26]

Participants

5

Reactant 3

HCID 177AcetaldehydeHCID 5003444Sodium cyanoborohydrideHCID 70872587Tert-butyl 9-phenyl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate

Product 1

HCID 70872962Tert-butyl 8-ethyl-9-phenyl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylateYield 82%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of tert-butyl 9-phenyl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate (336 mg, 1.01 mmol) in ethanol (3 mL) was added acetaldehyde (62 μL, 1.11 mmol) then sodium cyanoborohydride (89 mg, 1.42 mmol) and the reaction mixture was stirred for 2 hours. The reaction mixture was concentrated in vacuo, partitioned between DCM (50 mL) and 1:1 aq. sat. NaHCO3/25% NaOH (10 mL), and the aqueous layer was further extracted with DCM (2×25 mL). The combined organics were dried with MgSO4 and concentrated in vacuo to give tert-butyl 8-ethyl-9-phenyl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate (298 mg, 82%). ESI-MS m/z calc. 360.5. found 361.7 (M+1)+; Retention time: 1.30 minutes (3 min run).

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. custompartitioned between DCM (50 mL) and 1:1 aq. sat. NaHCO3/25% NaOH (10 mL)
  3. extractionthe aqueous layer was further extracted with DCM (2×25 mL)
  4. dry with materialThe combined organics were dried with MgSO4
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-dea460eedce341788726e0912b912090
Source dataset
uspto-grants-2015_11
Patent number
US09181273B2

Reaction notes

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