Tetrahydrofuran → 4-tert-butoxycarbonyl-2-bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

HRID 1363302Notes

Reaction equation

HRID 1363302 reaction equation
[CH3:1][O:2][C:3]([C:5]1[N:9]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C:8]2[CH:17]=[CH:18][O:19][C:7]=2[CH:6]=1)=[O:4].CCCC[N+](CCCC)(CCCC)CCCC.[F-].C1COCC1.C1C(=O)N([Br:50])C(=O)C1>C(Cl)Cl>[CH3:1][O:2][C:3]([C:5]1[N:9]([C:10]([O:12][C:13]([CH3:16])([CH3:14])[CH3:15])=[O:11])[C:8]2[CH:17]=[C:18]([Br:50])[O:19][C:7]=2[CH:6]=1)=[O:4]

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 67184N-bromobutanimideHCID 2724141Tetrabutylammonium FluorideHCID 596486034-tert-butoxycarbonyl-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

Product 1

HCID 596486644-tert-butoxycarbonyl-2-bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl esterYield 65%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 4-tert-butoxycarbonyl-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester (100 mg, 0.38 mmol) in DCM (1 mL) was added a solution of TBAF in THF (1.0 M, 0.57 ml, 0.57 mmol) followed by the addition of NBS (87 mg, 0.49 mmol). The resulting mixture was stirred at rt overnight. The reaction mixture was diluted with DCM (10 mL), washed with 10 mL of water and then with 10 mL of brine and dried with Na2SO4. The solid was removed by filtration. The filtrate was concentrated by evaporation. The crude product was purified by chromatography (0-20% EtOAc in hexane) to give 85 mg of 4-tert-butoxycarbonyl-2-bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester (85 mg, 65%). 1H NMR (400 MHz, CDCl3) δ (ppm) 6.81 (s, 1H), 6.61 (s, 1H), 3.83 (s, 3H), 1.59 (s, 9H).

Workup

  1. washwashed with 10 mL of water
  2. dry with materialwith 10 mL of brine and dried with Na2SO4
  3. customThe solid was removed by filtration
  4. concentrationThe filtrate was concentrated by evaporation
  5. customThe crude product was purified by chromatography (0-20% EtOAc in hexane)

Sources & evidence

ORD record
ord-2f82a492ee824ad4b04d1ce826c6baba
Source dataset
uspto-grants-2011_02
Patent number
US07884124B2

Reaction notes

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