Tert-butyl 4-(4-bromo-3-fluorophenyl)-4-oxobutylcarbamate → 5-(4-bromo-3-fluorophenyl)-3,4-dihydro-2H-pyrrole

HRID 415151Notes

Reaction equation

HRID 415151 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=O)[CH2:9][CH2:10][CH2:11][NH:12]C(=O)OC(C)(C)C)=[CH:4][C:3]=1[F:21]>C(O)=O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:9][CH2:10][CH2:11][N:12]=2)=[CH:4][C:3]=1[F:21]

Participants

3

Reactant 1

HCID 66621053Tert-butyl 4-(4-bromo-3-fluorophenyl)-4-oxobutylcarbamate

Product 1

HCID 666213385-(4-bromo-3-fluorophenyl)-3,4-dihydro-2H-pyrroleYield 82%

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Procedure

A solution of tert-butyl 4-(4-bromo-3-fluorophenyl)-4-oxobutylcarbamate (23 g, 64.07 mmol) in formic acid (290 mL) was heated at 40° C. for 5 hours. The reaction mixture was cooled, concentrated and the residue was partitioned between ethyl acetate and aqueous sodium hydroxide. The organic phase was washed with water, dried over magnesium sulfate, filtered and concentrated. The residue was purified by flash chromatography on silica gel, using a gradient of 20-60% ethyl acetate in petroleum ether to give 5-(4-bromo-3-fluorophenyl)-3,4-dihydro-2H-pyrrole (12.7 g, yield 82%). LC-MS (ESI) m/z: 242 (M+1)+.

Workup

  1. temperatureThe reaction mixture was cooled
  2. concentrationconcentrated
  3. customthe residue was partitioned between ethyl acetate and aqueous sodium hydroxide
  4. washThe organic phase was washed with water
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by flash chromatography on silica gel

Sources & evidence

ORD record
ord-d2f98781a1b446188fafc15dca759851
Source dataset
uspto-grants-2012_01
Patent number
US08088760B2

Reaction notes

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