Acetic Acid → tert-Butyl 4-((2-bromophenyl)amino)piperidine-1-carboxylate

HRID 1093532Notes

Reaction equation

HRID 1093532 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11](=O)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Br:15][C:16]1[CH:22]=[CH:21][CH:20]=[CH:19][C:17]=1[NH2:18].C(O)(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>ClCCCl>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][CH:11]([NH:18][C:17]2[CH:19]=[CH:20][CH:21]=[CH:22][C:16]=2[Br:15])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 119922-BromoanilineHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylateHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 43652150tert-Butyl 4-((2-bromophenyl)amino)piperidine-1-carboxylateYield 36%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

To a stirred solution of 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (0.5 g, 0.0025 mole) in dry 1,2-dichloroethane (5 mL) under an atmosphere of nitrogen was added 2-bromoaniline (0.474 g, 0.00276 mole), acetic acid (0.18 g, 0.00301 mole) and sodium triacetoxyborohydride (0.638 g, 0.00301 mole). Stirring was continued at ambient temperature for 14 hours. The reaction mixture was quenched in cold aqueous 1N NaOH solution and the product extracted with ether. The organic layer was washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure to afford the crude product as transparent viscous liquid. Purification by column chromatography using silica gel 60-120 mesh (2% ethyl acetate in hexane) afforded 0.320 g (35%) of desired 4-(2-bromo-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester. 1H NMR (DMSO-d6): δ 7.44-7.38 (m, 1H), 7.2-7.12 (m, 1H), 6.84-6.78 (m, 1H), 6.58-6.48 (m, 1H), 4.65 (d, 1H), 3.9 (m, 2H), 3.5 (m, 1H), 3.0-2.8 (m, 2H), 2.0-1.8 (m, 2H), 1.4 (s, 9H). To a cooled solution (0° C.) of 4-(2-bromo-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester (0.31 g, 0.00087 mole) in dioxane (0.5 mL) was added dioxane.HCl (2.5 mL). The mixture was stirred at the same temperature for 10 minutes, then gradually brought to ambient temperature with continued stirring for a further 15 minutes. The reaction mixture was evaporated under reduced pressure to afford a residue which was washed with dry ether to afford 0.106 g (42%) of 2-bromo-phenyl)-piperidin-4-yl-amine dihydrochloride.

Workup

  1. customThe reaction mixture was quenched in cold aqueous 1N NaOH solution
  2. extractionthe product extracted with ether
  3. washThe organic layer was washed with brine solution
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customto afford the crude product as transparent viscous liquid
  7. customPurification by column chromatography

Sources & evidence

ORD record
ord-4ff9d5716b8b4b4094a9295e48d02f2b
Source dataset
uspto-grants-2012_03
Patent number
US08129376B2

Reaction notes

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