Acetic Acid → TERT-BUTYL 4-(INDOLIN-1-YL)PIPERIDINE-1-CARBOXYLATE

HRID 1922470Notes

Reaction equation

HRID 1922470 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][CH2:2]1.O=[C:11]1[CH2:16][CH2:15][N:14]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:13][CH2:12]1.C(O)(=O)C.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+].[OH-].[Na+]>ClCCCl>[N:1]1([CH:11]2[CH2:16][CH2:15][N:14]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:13][CH2:12]2)[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][CH2:2]1

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 10328IndolineHCID 14798Sodium HydroxideHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylateHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 11449513TERT-BUTYL 4-(INDOLIN-1-YL)PIPERIDINE-1-CARBOXYLATEYield 99%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

A solution of indoline 1 (2.0 g, 16.78 mmol), tert-butyl 4-oxopiperidine-1-carboxylate (3.68 g, 18.46 mmol) in dry 1,2-dichloroethane (30 mL) was treated with acetic acid (2.4 mL, 42.00 mmol) followed by NaBH(OAc)3 (5.34 g, 25.2 mmol) at 0° C. The resulting mixture was brought to room temperature and stirred for 3 h. The reaction was basified with 1 N NaOH solution (50 mL) and product was extracted into ethyl acetate (2×50 mL). The combined ethyl acetate layer was washed with brine (25 mL) and dried (Na2SO4). The solvent was evaporated and crude was purified by column chromatography (ethyl acetate:hexanes, 1:4) to obtain compound 2 (5.0 g, 99%) as a syrup. 1H NMR (CDCl3) δ 7.05 (t, 2H, J=7.8 Hz), 6.62 (t, 1H, J=7.2 Hz), 6.43 (d, 11, J=7.5 Hz), 4.25-4.20 (m, 2H), 3.55-3.46 (m, 2H), 3.35 (t, 2H, J=8.4 Hz), 2.95 (t, 2H, J=8.4 Hz), 2.77 (t, 2H, J=12.3 Hz), 1.81-1.77 (m, 2H), 1.63-1.51 (m, 2H), 1.47 (s, 9H); ESI-MS (m/z, %) 303 (MH+, 5), 247 (100).

Workup

  1. customwas brought to room temperature
  2. extractionwas extracted into ethyl acetate (2×50 mL)
  3. washThe combined ethyl acetate layer was washed with brine (25 mL)
  4. dry with materialdried (Na2SO4)
  5. customThe solvent was evaporated
  6. customcrude was purified by column chromatography (ethyl acetate:hexanes, 1:4)

Sources & evidence

ORD record
ord-6e8edecee5c64d529ebc1db34234fa0b
Source dataset
uspto-grants-2012_05
Patent number
US08173813B2

Reaction notes

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