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

HRID 1350696Notes

Reaction equation

HRID 1350696 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-7ec08e57fc5b47a582eed32bd3685808
Source dataset
uspto-grants-2007_05
Patent number
US07214802B2

Reaction notes

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