Hydrogen Bromide → 5-(4-bromo-but-1-enyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester

HRID 2191496Notes

Reaction equation

HRID 2191496 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:7]([CH3:23])=[C:8]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[NH:9][C:10]=1[CH:11]([CH:13]1[CH2:15][CH2:14]1)O)=[O:5])[CH3:2].[BrH:24]>C(O)C>[CH2:1]([O:3][C:4]([C:6]1[C:7]([CH3:23])=[C:8]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[NH:9][C:10]=1[CH:11]=[CH:13][CH2:14][CH2:15][Br:24])=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 498403972-O-tert-butyl 4-O-ethyl 5-[cyclopropyl(hydroxy)methyl]-3-methyl-1H-pyrrole-2,4-dicarboxylate

Product 1

HCID 685244215-(4-bromo-but-1-enyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl esterYield 89.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

5-(Cyclopropyl-hydroxy-methyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 60a (323 mg, 1 mmol) was dissolved in 4 ml of ethanol under stirring, and added with hydrobromic acid (2.8 ml, 40%) to the solution and stirred for 30 minutes at room temperature. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was extracted with ethyl acetate (10 ml×5). The combined organic extracts were washed with saturated brine (15 ml), dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound 5-(4-bromo-but-1-enyl)-3-methyl-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 60b (345 mg, yield 89.5%) as a white solid.

Workup

  1. stirringstirred for 30 minutes at room temperature
  2. extractionthe reaction mixture was extracted with ethyl acetate (10 ml×5)
  3. washThe combined organic extracts were washed with saturated brine (15 ml)
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. customto remove the drying agent
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-5a2b2e14abb74f61bc0ec0a3e11c4b3d
Source dataset
uspto-grants-2012_12
Patent number
US08329682B2

Reaction notes

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