2,2-Difluoro-2-(fluorosulfonyl)acetic acid → 4-Difluoromethoxymethyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

HRID 71987

Reaction equation

HRID 71987 reaction equation
[CH3:1][O:2][C:3]([CH:5]1[CH2:9][CH:8]([CH2:10][OH:11])[CH2:7][N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4].[F:19][C:20]([F:28])(S(F)(=O)=O)C(O)=O>CC#N.[Cu]I>[CH3:1][O:2][C:3]([CH:5]1[CH2:9][CH:8]([CH2:10][O:11][CH:20]([F:28])[F:19])[CH2:7][N:6]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:4]

Participants

5

Conditions

Temperature
45 °C

Procedure

4-Hydroxymethyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (584 mg, 2.25 mmol) and CuI (86 mg, 0.45 mmol) were suspended in MeCN (10 mL). The reaction mixture was heated to 45° C. and difluoro-fluorosulfonyl-acetic acid (0.465 mL, 4.5 mmol) was added dropwise over the course of 30 min. Stirring was continued for another 3 h, after which the reaction mixture was cooled to RT and concentrated. The residue was taken up in EtOAc and washed with saturated aqueous NaHCO3 and brine then dried over MgSO4, filtered and concentrated. The crude residue was purified by silica column chromatography (19% to 40% EtOAc/Hex) to afford the title compound (394 mg, 57%).

Workup

  1. temperatureafter which the reaction mixture was cooled to RT
  2. concentrationconcentrated
  3. washwashed with saturated aqueous NaHCO3 and brine
  4. dry with materialthen dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe crude residue was purified by silica column chromatography (19% to 40% EtOAc/Hex)

Sources & evidence

ORD record
ord-4cfea0ab1ee74bcf8c1179e6864cb549
Source dataset
uspto-grants-2014_09
Patent number
US08822430B2

Linked notes

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