Trimethylsilylacetylene → 1-methyl-5-trimethylsilanylethynyl-1H-imidazole-2-carboxylic acid ethyl ester

HRID 2109201Notes

Reaction equation

HRID 2109201 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[N:7]([CH3:12])[C:8](Br)=[CH:9][N:10]=1)=[O:5])[CH3:2].[CH3:13][Si:14]([C:17]#[CH:18])([CH3:16])[CH3:15]>CCN(CC)CC.C1COCC1.[Cu]I.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:1]([O:3][C:4]([C:6]1[N:7]([CH3:12])[C:8]([C:18]#[C:17][Si:14]([CH3:16])([CH3:15])[CH3:13])=[CH:9][N:10]=1)=[O:5])[CH3:2]

Participants

7

Reactant 2

HCID 66111TrimethylsilylacetyleneHCID 58861475Ethyl 5-bromo-1-methyl-1H-imidazole-2-carboxylate

Product 1

HCID 588614711-methyl-5-trimethylsilanylethynyl-1H-imidazole-2-carboxylic acid ethyl esterYield 24.1%

Reagents, catalysts & solvents 4

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolventHCID 8471TriethylamineSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of 800 mg (3.43 mmol) of 5-bromo-1-methyl-1H-imidazole-2-carboxylic acid ethyl ester in Et3N (10 mL) and THF (10 mL) was added 33 mg (0.17 mmol) of CuI and 120 mg (0.10 mmol) of Pd(PPh3)4. Trimethylsilylacetylene (0.48 mL, 3.4 mmol) was then added and the reaction was heated at 70° C. under N2. After 12 h, the mixture was cooled and filtered though a pad of celite, and then concentrated and chromatographed (0-50% EtOAc in hexanes) to give 1-methyl-5-trimethylsilanylethynyl-1H-imidazole-2-carboxylic acid ethyl ester as a brown oil (205 mg).

Workup

  1. temperaturethe mixture was cooled
  2. filtrationfiltered though a pad of celite
  3. concentrationconcentrated
  4. customchromatographed (0-50% EtOAc in hexanes)

Sources & evidence

ORD record
ord-a8821904fc924aff9410bae47f10b2c8
Source dataset
uspto-grants-2009_04
Patent number
US07514458B2

Reaction notes

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