Methanol → Methyl 4-bromo-1H-pyrrole-2-carboxylate

HRID 406907Notes

Reaction equation

HRID 406907 reaction equation
[Br:1][C:2]1[CH:3]=[C:4](C(=O)C(Cl)(Cl)Cl)[NH:5][CH:6]=1.[CH3:13][O-:14].[Na+].[CH3:16][OH:17]>O>[Br:1][C:2]1[CH:3]=[C:4]([C:13]([O:17][CH3:16])=[O:14])[NH:5][CH:6]=1

Participants

5

Reactant 3

HCID 887MethanolHCID 27981401-(4-bromo-1H-pyrrol-2-yl)-2,2,2-trichloroethanoneHCID 10942334Sodium Methoxide

Product 1

HCID 2763594Methyl 4-bromo-1H-pyrrole-2-carboxylateYield 85%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a solution of Example 1B (20 g, 68 mmol) in methanol (100 mL), a solution of NaOMe (1M in MeOH, 34 mL, 34 mmol) was added slowly. This mixture was then stirred at ambient temperature for 1 h after which it was diluted with water (300 mL) and the organic layer was separated. The aqueous phase was extracted with CH2Cl2 and the combined organic layer and extracts were washed with water (2×50 mL), dried (MgSO4) and evaporated under reduced pressure. Recrystallization of the residue from hexane gave 4-Bromo-2-methoxycarbonylpyrrole (Example 1C, 12 g, 85%) as a white solid. LC-MS, [M−H]+=203. 1H NMR (DMSO-d6, 400 MHz): δ 12.31 (brs, 1H), 7.16 (s, 1H), 6.81 (s, 1H), 3.75 (s, 3H).

Workup

  1. customthe organic layer was separated
  2. extractionThe aqueous phase was extracted with CH2Cl2
  3. washthe combined organic layer and extracts were washed with water (2×50 mL)
  4. dry with materialdried (MgSO4)
  5. customevaporated under reduced pressure
  6. customRecrystallization of the residue from hexane

Sources & evidence

ORD record
ord-38f16d2f412f41de92f11abaf517e1fd
Source dataset
uspto-grants-2014_06
Patent number
US08754211B2

Reaction notes

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