Acetic Acid → 4-(2,3-Dimethyl-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester

HRID 1093538Notes

Reaction equation

HRID 1093538 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].[CH3:15][C:16]1[C:22]([CH3:23])=[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+].C(=O)(O)[O-].[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]=[C:22]([CH3:23])[C:16]=2[CH3:15])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 68932,3-DimethylanilineHCID 516892Sodium BicarbonateHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylateHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 213525804-(2,3-Dimethyl-phenylamino)-piperidine-1-carboxylic acid tert-butyl esterYield 98.2%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

To a stirred solution of 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (1 g, 0.00502 mole) in dry 1,2-dichloroethane (10 mL) (under an atmosphere of nitrogen for 10 minutes) was added 2,3-dimethylaniline (0.73 g, 0.00602 mole), acetic acid (0.301 g, 0.005 mole) and sodium triacetoxyborohydride (1.596 g, 0.00753 mole) portionwise with stirring. The stirring was continued at ambient temperature for a further 16 hours. The reaction mixture was basified with sodium bicarbonate solution and the product extracted with dichloromethane. The dichloromethane layer was washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure to as afford a transparent viscous liquid which was purified by column chromatography using neutral aluminium oxide (1% ethyl acetate in hexane) to afford 1.5 g (98%) of 4-(2,3-dimethyl-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester. 1H NMR (CDCl3): δ 7.0 (t, 1H), 6.6 (m, 2H), 4.1 (m, 2H), 3.5 (m, 1H), 3.0-2.9 (t, 2H), 2.3 (s, 3H), 2.1 (m, 2H), 2.0 (s, 3H), 1.5 (s, 9H), 1.4 (m, 2H). A solution of 4-(2,3-dimethyl-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester (1.45 g, 0.00476 mole) in ethyl acetate.HCl (15 mL) was stirred at ambient temperature for 2 hours. The reaction mixture was concentrated under reduced pressure and the resulting residue was washed with ether and dried to afford 1.1 g (83) of (2,3-dimethyl-phenyl)-piperidin-4-yl-amine dihydrochloride. LCMS: 205.16 (M+1)+, 95.98%, 1H NMR (DMSO-d6): δ 9.4 (d, 1H), 9.0 (d, 1H), 7.3 (m, 3H), 3.7 (m, 2H), 3.3 (d, 2H), 3.1 (bs, 1H), 2.9 (m, 2H), 2.3 (d, 6H), 2.1 (m, 4H).

Workup

  1. extractionthe product extracted with dichloromethane
  2. washThe dichloromethane layer was washed with brine solution
  3. dry with materialdried over sodium sulfate
  4. concentrationconcentrated under reduced pressure
  5. customto as afford a transparent viscous liquid which
  6. customwas purified by column chromatography

Sources & evidence

ORD record
ord-98833b7d72604b7bb7282d0593028eb9
Source dataset
uspto-grants-2012_03
Patent number
US08129376B2

Reaction notes

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