1-Phenethylamine, (-)- → (S)-tert-butyl 4-(1-phenylethylimino)-3,4-dihydro-2H-spiro[naphthalene-1,4'-piperidine]-1'-carboxylate

HRID 1873659Notes

Reaction equation

HRID 1873659 reaction equation
O=[C:2]1[C:23]2[C:18](=[CH:19][CH:20]=[CH:21][CH:22]=2)[C:5]2([CH2:10][CH2:9][N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:7][CH2:6]2)[CH2:4][CH2:3]1.[C:24]1([C@@H:30]([NH2:32])[CH3:31])[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.[B-](F)(F)(F)[O+](C)C>C1(C)C=CC=CC=1>[C:24]1([C@@H:30]([N:32]=[C:2]2[C:23]3[C:18](=[CH:19][CH:20]=[CH:21][CH:22]=3)[C:5]3([CH2:10][CH2:9][N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:7][CH2:6]3)[CH2:4][CH2:3]2)[CH3:31])[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

5

Procedure

A solution of tert-butyl 4-oxo-3,4-dihydro-2H-spiro[naphthalene-1,4′-piperidine]-1′-carboxylate (A4) (5.0 g, 15.8 mmol), (S)-1-phenylethanamine (3.0 ml, 23.8 mmol) and boron trifluoride dimethyl etherate (0.5 ml, 5 mmol) in dry toluene (150 ml) was heated at 140° C. under a Dean-Stark trap for 24 hours. The solvent was distilled and the residue was cooled with an ice bath, dissolved in ethyl acetate, washed with saturated NaHCO3, and water. The organic phase was dried over Na2SO4, filtered and concentrated to give (S)-tert-butyl 4-(1-phenylethylimino)-3,4-dihydro-2H-spiro[naphthalene-1,4′-piperidine]-1′-carboxylate (B1) as a gum. LC-MS analysis of the crude indicated that there is trace of starting material (A4). LC-MS: m/e=419.37 (M+H). Rt=2.24 min.

Workup

  1. distillationThe solvent was distilled
  2. temperaturethe residue was cooled with an ice bath
  3. dissolutiondissolved in ethyl acetate
  4. washwashed with saturated NaHCO3, and water
  5. dry with materialThe organic phase was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-83cea678454f4d92ad036baf1d884ec7
Source dataset
uspto-grants-2012_11
Patent number
US08304423B2

Reaction notes

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