HCID 68778166, compound → HCID 59853565, compound

HRID 730526Notes

Reaction equation

HRID 730526 reaction equation
FC(F)(F)C(O)=O.[CH2:8]([O:11][C:12]([CH:14]1[CH2:18][C:17](F)([F:19])[CH2:16][NH:15]1)=[O:13])[CH:9]=[CH2:10]>O1CCCC1.C(OCC)(=O)C.[O-2].[O-2].[Mn+4]>[CH2:8]([O:11][C:12]([C:14]1[NH:15][CH:16]=[C:17]([F:19])[CH:18]=1)=[O:13])[CH:9]=[CH2:10]

Participants

5

Reactant 1

HCID 68778166HCID 68778166, compound

Product 1

HCID 59853565HCID 59853565, compoundYield 88.7%

Reagents, catalysts & solvents 3

HCID 178418406HCID 178418406, compoundCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of 4,4-Difluoro-pyrrolidine-2-carboxylic acid allyl ester trifluoroacetic acid salt (Example 14d, 6.13 g, 20.08 mmol) in anhydrous tetrahydrofuran (300 mL) was added manganese(IV) dioxide and the reaction mixture was heated at 80° C. for 4 h. The mixture was filtered over Celite, and was washed with hot and then cold tetrahydrofuran. The filtrate was concentrated in vacuo to give a dark orange oil. The oil was dissolved in ethyl acetate and the organic layer was washed with saturated aqueous sodium bicarbonate solution. The solvent was removed in vacuo to give an orange oil, which was purified by flash column chromatography (Merck silica gel 60, 40-63 μm, 30% ethyl acetate in hexanes) to afford the desired product, 4-fluoro-1H-pyrrole-2-carboxylic acid allyl ester (3.01 g, 17.80 mmol, 88.7% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3) δ: 4.77 (2H, d, J=5.7 Hz), 5.29 (1H, d, J=10.2 Hz), 5.38 (1H, d, J=15.9 Hz), 5.94-6.04 (1H, m), 6.64-6.65 (1H, m), 6.72-6.74 (1H, m), 8.91 (1H, bs).

Workup

  1. filtrationThe mixture was filtered over Celite
  2. washwas washed with hot and then cold tetrahydrofuran
  3. concentrationThe filtrate was concentrated in vacuo
  4. customto give a dark orange oil
  5. washthe organic layer was washed with saturated aqueous sodium bicarbonate solution
  6. customThe solvent was removed in vacuo
  7. customto give an orange oil, which
  8. customwas purified by flash column chromatography (Merck silica gel 60, 40-63 μm, 30% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-e423a0c6f9fb4c979259c01a8173b38b
Source dataset
uspto-grants-2009_09
Patent number
US07582754B2

Reaction notes

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