N-bromobutanimide → 6-Bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

HRID 1363300Notes

Reaction equation

HRID 1363300 reaction equation
[O:1]1[C:8]2[CH:7]=[C:6]([C:9]([O:11][CH3:12])=[O:10])[NH:5][C:4]=2[CH:3]=[CH:2]1.CCCC[N+](CCCC)(CCCC)CCCC.[F-].C1C(=O)N([Br:38])C(=O)C1>C(Cl)Cl>[Br:38][C:7]1[C:8]2[O:1][CH:2]=[CH:3][C:4]=2[NH:5][C:6]=1[C:9]([O:11][CH3:12])=[O:10]

Participants

5

Reactant 3

HCID 67184N-bromobutanimideHCID 2724141Tetrabutylammonium FluorideHCID 5082263methyl 4H-furo[3,2-b]pyrrole-5-carboxylate

Product 1

HCID 596486446-Bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a cold solution (ice-water bath) of methyl 4H-furo[3,2-b]pyrrole-5-carboxylate (1.0 g, 6.05 mmol) in DCM (10 mL) was added TBAF (1.0 M in THF, 9.0 mL, 9.0 mmol) and NBS (1.5 g, 7.9 mmol). The resulting dark colored solution was stirred from 0° C. to rt overnight. The reaction mixture was diluted with 50 mL of CH2Cl2 and washed with water (100 mL) and brine (100 mL) and dried (Na2SO4). After filtration, the filtrate was concentrated by evaporation and the crude product was purified by silica gel chromatography (0-5% EtOAc/hexane) to afford a white solid. 1H NMR (400 MHz, CDCl3) δ (ppm) 8.84 (broad, 1H, NH), 7.54 (d, J=2.2 Hz, 1H), 6.48 (d, J=1.83 Hz, 1H), 3.92 (s, 3H) ppm; m+/z 244 (100%), 246 (100%).

Workup

  1. washwashed with water (100 mL) and brine (100 mL)
  2. dry with materialdried (Na2SO4)
  3. filtrationAfter filtration
  4. concentrationthe filtrate was concentrated by evaporation
  5. customthe crude product was purified by silica gel chromatography (0-5% EtOAc/hexane)
  6. customto afford a white solid

Sources & evidence

ORD record
ord-05c46f1a29ae460fbb5ba364793e2caf
Source dataset
uspto-grants-2011_02
Patent number
US07884124B2

Reaction notes

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