Aniline → 1-Phenoxy-2,2,6,6-tetramethylpiperidine

HRID 1760315Notes

Reaction equation

HRID 1760315 reaction equation
[CH3:1][C:2]1([CH3:11])[N:7]([O])[C:6]([CH3:10])([CH3:9])[CH2:5][CH2:4][CH2:3]1.[C:12]([O:16]N=O)(C)([CH3:14])[CH3:13].N[C:20]1[CH:25]=CC=C[CH:21]=1>N1C=CC=CC=1.[Fe]>[O:16]([N:7]1[C:2]([CH3:11])([CH3:1])[CH2:3][CH2:4][CH2:5][C:6]1([CH3:10])[CH3:9])[C:12]1[CH:14]=[CH:25][CH:20]=[CH:21][CH:13]=1

Participants

6

Reactant 3

HCID 6115Aniline2×HCID 10906Tert-Butyl nitriteHCID 2724126Tempo

Product 1

HCID 132131751-Phenoxy-2,2,6,6-tetramethylpiperidineYield 72.2%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 1049PyridineSolvent2×

Procedure

To a suspension of 1.95 g (12.5 mmol) of 2,2,6,6-tetramethylpiperidine-1-oxyl, 3.09 g (30.0 mmol) of tert-butylnitrite and 378 mg (˜0.125 mmol) of iron polyoxometallate (K7PFeW11O39•H2O) in 100 mL of pyridine at 70° C. under a nitrogen atmosphere is added dropwise over 5 minutes 2.32 g (25 mmol) of aniline in 5 mL of pyridine. Evolution of gas is observed during the addition of aniline. The dark red reaction mixture is kept at 70° C. until evolution of gas subsided. Upon cooling to ambient temperature, the reaction mixture is then concentrated to an thick oil. The residue is purified by vacuum flash chromatography (heptane) to give 2.10 g of a colorless oil in 72.2% yield: 1H NMR (CDCL3) (300.08 MHz) d 1.42, 1.29, 1.12 (overlapping m, CH2, 6 H), 1.16 (s, CH3, 6 H), 1.017 (s, CH3, 6 H), 7.25 (d, CH, 2H, 3JHH′=8.2 Hz), 7.12 (dd, CH, 2H, 3JHH′=8.3 Hz, 3JHH′=8.2 Hz), 6.78 (tt, CH, 1 H, 3JHH′=7.2 Hz, 4JHH″=1.2 Hz); MS [M+1]234.

Workup

  1. customThe dark red reaction mixture
  2. customis kept at 70° C. until evolution of gas
  3. concentrationthe reaction mixture is then concentrated to an thick oil
  4. customThe residue is purified by vacuum flash chromatography (heptane)

Sources & evidence

ORD record
ord-bfbc5ab64d0f47198110d6525898dabc
Source dataset
uspto-grants-2005_01
Patent number
US06841668B2

Reaction notes

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