tert-Butyl acetate → tert-butyl 3-bromo-4-chloro-5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrole-2-carboxylate

HRID 1948379Notes

Reaction equation

HRID 1948379 reaction equation
[Br:1][C:2]1[C:6]([Cl:7])=[C:5]([CH3:8])[N:4]([CH2:9][O:10][CH2:11][CH2:12][Si:13]([CH3:16])([CH3:15])[CH3:14])C=1C(OCC)=O.[C:22]([O:26][C:27](=[O:29])[CH3:28])([CH3:25])([CH3:24])[CH3:23].CC(C)([O-])C.[K+]>>[Br:1][C:2]1[C:6]([Cl:7])=[C:5]([CH3:8])[N:4]([CH2:9][O:10][CH2:11][CH2:12][Si:13]([CH3:14])([CH3:16])[CH3:15])[C:28]=1[C:27]([O:26][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:29]

Participants

4

Reactant 3

HCID 10908tert-Butyl acetate2×HCID 23665647Potassium tert-butoxide2×HCID 68515032Ethyl 3-bromo-4-chloro-5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrole-2-carboxylate2×

Product 1

HCID 59406885tert-butyl 3-bromo-4-chloro-5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrole-2-carboxylateYield 80.4%

Procedure

Ethyl 3-bromo-4-chloro-5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrrole-2-carboxylate (Intermediate 266, 564 mg, 1.42 mmol), t-Butylacetate (330 mg, 2.84 mmol) and potassium t-butoxide (0.14 mmol) were mixed together and stirred at room temperature for 10 minutes, concentrated to an oil under vacuum. t-Butylacetate (330 mg, 2.84 mmol) and potassium t-butoxide (0.14 mmol) were added again into the reaction mixture, repeated the same procedure again. The resulting reaction crude was filtered through a short pass silica gel, washed with ethyl acetate, the combined filtrate was concentrated to an oil and purified by column chromatography (2% ethyl acetate in hexanses) to give the desired product as an oil (485 mg).

Workup

  1. concentrationconcentrated to an oil under vacuum
  2. customThe resulting reaction crude
  3. filtrationwas filtered through a short pass silica gel
  4. washwashed with ethyl acetate
  5. concentrationthe combined filtrate was concentrated to an oil
  6. custompurified by column chromatography (2% ethyl acetate in hexanses)

Sources & evidence

ORD record
ord-0996c6e358624c2c8e1eb14fa9c436cd
Source dataset
uspto-grants-2013_03
Patent number
US08399489B2

Reaction notes

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