Potassium Permanganate → Tert-butyl 4-oxo-3,4-dihydro-2H-spiro[naphthalene-1,4'-piperidine]-1'-carboxylate

HRID 1009815Notes

Reaction equation

HRID 1009815 reaction equation
[N:1]1([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:6][CH2:5][C:4]2([C:15]3[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=3)[CH2:9][CH2:8][CH2:7]2)[CH2:3][CH2:2]1.[Mn]([O-])(=O)(=O)=[O:24].[K+]>C(#N)C>[O:24]=[C:9]1[C:10]2[C:15](=[CH:14][CH:13]=[CH:12][CH:11]=2)[C:4]2([CH2:5][CH2:6][N:1]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:2][CH2:3]2)[CH2:7][CH2:8]1

Participants

4

Reactant 2

HCID 516875Potassium Permanganate2×HCID 58966615tert-Butyl 3,4-dihydro-1'H,2H-spiro[naphthalene-1,4'-piperidine]-1'-carboxylate

Product 1

HCID 49760950Tert-butyl 4-oxo-3,4-dihydro-2H-spiro[naphthalene-1,4'-piperidine]-1'-carboxylate

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of the Boc-piperidine (602 mg, 2 mmol) in acetonitrile (10 ml) was added potassium permanganate (KMnO4, 950 mg, 6 mmol). The reaction mixture was stirred at 70° C. for 15 hours, filtered through Celite, and the filter cake was washed with dichloromethane. The filtrate and washings were concentrated and the residue was dissolved in acetonitrile (10 ml) and reacted with KMnO4 (950 mg, 6 mmol) at 70° C. for another 24 hours. After filtration, washing and concentrating, the residue was purified by flash column chromatography (CH2Cl2/CH3CN: 1:0 to 9:1) to provide tert-butyl 4-oxo-3,4-dihydro-2H-spiro[naphthalene-1,4′-piperidine]-1′-carboxylate (A4). LC-MS: m/e=260.0 (M+H−tBu). Rt=3.46 min. 1H-NMR (500 MHz, CDCl3): 8.07 (dd, J=1.5, 7.8, 1H), 7.60-7.57 (td, J=7.9, 1.2, 1H), 7.50 (d, J=7.9, 1H), 7.36 (t, J=7.6, 1.0, 1H), 4.10 (br.d, J=13.2, 2H), 3.08 (t, J=13.8, 2H), 2.71 (t, J=6.7, 2H), 2.27 (t, J=6.9, 2H), 2.05 (td, J=13.4, 4.7, 2H), 1.73 (br.d, J=13.2, 2H), 1.52 (s, 9H).

Workup

  1. filtrationfiltered through Celite
  2. washthe filter cake was washed with dichloromethane
  3. concentrationThe filtrate and washings were concentrated
  4. dissolutionthe residue was dissolved in acetonitrile (10 ml)
  5. filtrationAfter filtration
  6. washwashing
  7. concentrationconcentrating
  8. customthe residue was purified by flash column chromatography (CH2Cl2/CH3CN: 1:0 to 9:1)

Sources & evidence

ORD record
ord-384218883d0e48f499635ef589aa295f
Source dataset
uspto-grants-2011_07
Patent number
US07973162B2

Reaction notes

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