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

HRID 1873658Notes

Reaction equation

HRID 1873658 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-f6fd901c7de340d7a5b122684ae1f83c
Source dataset
uspto-grants-2012_11
Patent number
US08304423B2

Reaction notes

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