Acetic Acid → 3-[(4-Chloro-benzyl)-isobutyl-amino]-pyrrolidine-1-carboxylic acid tert-butyl ester

HRID 457191Notes

Reaction equation

HRID 457191 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH:10]([NH:13][CH2:14][C:15]2[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][CH:16]=2)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH:22](=O)[CH:23]([CH3:25])[CH3:24].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(O)(=O)C>ClC(Cl)C>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH:10]([N:13]([CH2:14][C:15]2[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][CH:16]=2)[CH2:22][CH:23]([CH3:25])[CH3:24])[CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

6

Procedure

To a solution of 3-(4-chloro-benzylamino)-pyrrolidine-1-carboxylic acid tert-butyl ester (0.4 g, 1.28 mmol) and isobutyraldehyde (0.14 g, 1.92 mmol) in dichloroethane was added sodium triacetoxy borohydride (0.81 g, 3.85 mmol) and catalytic acetic acid. The resulting reaction mixture was stirred at room temperature overnight. The reaction mixture was concentrated, dissolved in dichloromethane and washed with saturated aqueous sodium bicarbonate. The combined organics were washed with brine and dried over sodium sulfate. The crude product was purified on silica using gradient elution from hexane/ethyl acetate (10%) to hexane/ethyl acetate (50%). 1H-NMR (CDCl3) δ: 0.80 (6H, 2×d), 1.45 (9H, s), 1.60–1.90 (2H, m), 2.20 (2H, d), 3.00–3.70 (7H, m), 7.20 (4H,s). ESI-MS m/z: 367 (M+1), UV retention time: 1.89 min.

Workup

  1. customThe resulting reaction mixture
  2. concentrationThe reaction mixture was concentrated
  3. dissolutiondissolved in dichloromethane
  4. washwashed with saturated aqueous sodium bicarbonate
  5. washThe combined organics were washed with brine
  6. dry with materialdried over sodium sulfate
  7. customThe crude product was purified on silica using gradient elution from hexane/ethyl acetate (10%) to hexane/ethyl acetate (50%)

Sources & evidence

ORD record
ord-735ef3c0e81b4febb7058e9076677c09
Source dataset
uspto-grants-2007_03
Patent number
US07186729B2

Reaction notes

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