Methyl propiolate → Methyl 2-methyl-1H-imidazole-5-carboxylate

HRID 931345Notes

Reaction equation

HRID 931345 reaction equation
O[N:2]=[C:3]([NH2:5])[CH3:4].[C:6]([O:10][CH3:11])(=[O:9])[C:7]#[CH:8]>CO>[CH3:4][C:3]1[NH:5][C:7]([C:6]([O:10][CH3:11])=[O:9])=[CH:8][N:2]=1

Participants

4

Reactant 2

HCID 13536Methyl propiolateHCID 30926N-Hydroxyacetamidine

Product 1

HCID 13432302Methyl 2-methyl-1H-imidazole-5-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of N′-hydroxyethanimidamide (65 g, 880 mmol) in anhydrous methanol (2 L) was treated with methyl propiolate (100 g, 1.19 mol), and the reaction was heated at reflux for 4 hours. The reaction mixture was concentrated in vacuo, and the residue was diluted with diphenyl ether (1 L) and heated at reflux for 4 hours. The hot solution was filtered, and the filtrate was cooled to room temperature and diluted with hexanes (2 L). The resulting solid was washed with diethyl ether (1 L), to afford the product as a brown solid. Yield: 60 g, 430 mmol, 49%.

Workup

  1. temperaturethe reaction was heated
  2. temperatureat reflux for 4 hours
  3. concentrationThe reaction mixture was concentrated in vacuo
  4. additionthe residue was diluted with diphenyl ether (1 L)
  5. temperatureheated
  6. temperatureat reflux for 4 hours
  7. filtrationThe hot solution was filtered
  8. additiondiluted with hexanes (2 L)
  9. washThe resulting solid was washed with diethyl ether (1 L)

Sources & evidence

ORD record
ord-e16061c9c0d340a596addc0648099cde
Source dataset
uspto-grants-2016_03
Patent number
US09296761B2

Reaction notes

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