2-(1-Benzylpiperidin-4-yl)pyridine → 2-(Piperidin-4-yl)pyridine

HRID 278916Notes

Reaction equation

HRID 278916 reaction equation
C([N:8]1[CH2:13][CH2:12][CH:11]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=2)[CH2:10][CH2:9]1)C1C=CC=CC=1>CO.[OH-].[Pd+2].[OH-]>[N:15]1[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=1[CH:11]1[CH2:12][CH2:13][NH:8][CH2:9][CH2:10]1

Participants

4

Reactant 1

HCID 151233362-(1-Benzylpiperidin-4-yl)pyridine

Product 1

HCID 103747502-(Piperidin-4-yl)pyridineYield 100.3%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 887MethanolSolvent

Procedure

To 1-benzyl-4-(2-pyridyl)-piperidine (3.26 g, 12.9 mmol) in dry methanol (25 mL), 10% palladium hydroxide (1.9 g) was added and the solution was hydrogenated at 200 psi for 24 hours. The solution was filtered over celite, concentrated to give 2.1 g (99%) of 4-(2-pyridyl)-piperidine which was used as such for the subsequent step. A mixture of 3-bromopropylamine hydrobromide (20 g, 91.3 mmol), potassium carbonate (37.85 g, 273.9 mmol) and di-tert-butyldicarbonate (21.90 g, 100 mmol) in methanol was stirred at room temperature for 24 hours. The reaction mixture was concentrated and partitioned between 250 mL EtOAc and 50 mL water, dried over sodium sulfate, filtered and concentrated. Purification of the crude product by column chromatography (hexane: EtOAc, 4.5:0.5) gave 17.5 g (80%) of the product as a pale yellow oil. To a stirred solution of the 4-(2-pyridyl)-piperidine (1.86 g, 11.4 mmol) in dioxane (20 mL), N-(tert-butoxycarbonyl)-3-bromopropylamine (2.82 g, 11.4 mmol) and potassium carbonate (3.16 g, 22.9 mmol) were added and the solution was refluxed for 24 hours. The reaction mixture was cooled to room temperature, concentrated and partitioned between 40 mL chloroform and 5 mL water. The organic layer was dried over sodium sulfate, filtered and concentrated. The crude product was purified by column chromatography (ethyl acetate: methanol, 4:1) to yield 1.86 g (49%) of the required product as a colorless oil; 1H-NMR (CDCl3): δ1.45 (s, 9 H), 1.54-1.69 (m, 8 H), 2.21-2.68 (m, 2 H), 2.74-2.80 (m, 1 H), 3.02-3.22 (m, 4 H), 5.41 ( s, 1 H), 7.13-7.17 (m, 1 H), 7.33 (d, J=7.93 Hz, 1 H), 7.63 (t, J=7.6 Hz, 1 H), 8.54 (d, J=4.6 Hz, 1 H). To N-(tert-butoxycarbonyl)-3-[4-(2-pyridyl)-piperidin-1-yl]propylamine (0.15 g, 0.45 mmol) in 5 mL of dichloromethane, 1 mL of trifluoroacetic acid was added and the solution was stirred at room temperature for 1 hour. The solution was concentrated, neutralized with 10% KOH solution and extracted into 25 mL of dichloromethane. The organic layer was dried over sodium sulfate, filtered, and concentrated to give 0.098 g (100%) of 3-[4-2-pyridyl)-piperidin-1-yl]propylamine which was used as such for the subsequent step.

Workup

  1. filtrationThe solution was filtered over celite
  2. concentrationconcentrated

Sources & evidence

ORD record
ord-5053b66beea7490db3abca8cfd299720
Source dataset
uspto-grants-2002_03
Patent number
US06362182B1

Reaction notes

Loading…