4-Toluenesulfonyl chloride → 1-tert-Butyl 2-methyl (2S,4R)-4-[(4-methylbenzene-1-sulfonyl)oxy]pyrrolidine-1,2-dicarboxylate

HRID 1504324Notes

Reaction equation

HRID 1504324 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][C@H:11]([OH:13])[CH2:10][C@H:9]1[C:14]([O:16][CH3:17])=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2].CCN(C(C)C)C(C)C.[C:27]1([CH3:37])[CH:32]=[CH:31][C:30]([S:33](Cl)(=[O:35])=[O:34])=[CH:29][CH:28]=1>C(Cl)Cl.CN(C)C1C=CN=CC=1>[CH3:17][O:16][C:14]([C@@H:9]1[CH2:10][C@@H:11]([O:13][S:33]([C:30]2[CH:31]=[CH:32][C:27]([CH3:37])=[CH:28][CH:29]=2)(=[O:35])=[O:34])[CH2:12][N:8]1[C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])=[O:15]

Participants

6

Reactant 3

HCID 73974-Toluenesulfonyl chlorideHCID 81531DiisopropylethylamineHCID 2734883(2S,4R)-4-Hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

Product 1

HCID 134257721-tert-Butyl 2-methyl (2S,4R)-4-[(4-methylbenzene-1-sulfonyl)oxy]pyrrolidine-1,2-dicarboxylateYield 23%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of methyl (2S,4R)—N-tert-butoxycarbonyl-4-hydroxy-2-pyrrolidinecarboxylate (4.68 g, 19.1 mmol) in DCM (47 mL) at RT was added DIPEA (3.66 mL, 21.0 mmol) and 4-dimethylaminopyridine (233 mg, 1.91 mmol) followed by p-toluenesulfonyl chloride (3.82 g, 20.1 mmol). The reaction mixture was stirred at RT overnight, washed with 1N HCl (2 mL), saturated sodium bicarbonate (2 mL), and brine (2 mL), dried over sodium sulfate, filtered and concentrated to give a yellowish oil, which was purified by silica gel chromatography (80 g silica, 0-100% EtOAc/Hexanes). Desired fractions were combined and concentrated to give the title intermediate (1.74 g, 23% yield) as a colorless oil.

Workup

  1. washwashed with 1N HCl (2 mL), saturated sodium bicarbonate (2 mL), and brine (2 mL)
  2. dry with materialdried over sodium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customto give a yellowish oil, which
  6. customwas purified by silica gel chromatography (80 g silica, 0-100% EtOAc/Hexanes)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-c82bd4c588eb4e79b7901231688695d5
Source dataset
uspto-grants-2015_12
Patent number
US09212168B2

Reaction notes

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