Acetic Anhydride → 1-Acetyl-4-methylimidazole

HRID 2372805Notes

Reaction equation

HRID 2372805 reaction equation
[CH3:1][C:2]1[N:3]=[CH:4][NH:5][CH:6]=1.[C:7](OC(=O)C)(=[O:9])[CH3:8]>>[C:7]([N:5]1[CH:6]=[C:2]([CH3:1])[N:3]=[CH:4]1)(=[O:9])[CH3:8]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 178418800HCID 178418800, compound

Product 1

HCID 109534921-Acetyl-4-methylimidazoleYield 68.9%

Procedure

The 1-Acetyl-4-methylimidazole intermediate was prepared by making a mixture of 4-methylimidazole (82.1 g, 1.0 mol)) and acetic anhydride (190 mL, 2.0 mol) and refluxing for 15 min after which time 150 mL of solvent was removed by distillation at atmospheric pressure (head temperature 125° C.) over a 1 h period. The remaining acetic anhydride was removed at 50° C./0.5 mm and the residual liquid was crystallized from ether (150 mL) at -20° C. to give 85.5 g of 1-acetyl-4-methylimidazole product, m.p. 49°-51° C.

Workup

  1. customThe 1-Acetyl-4-methylimidazole intermediate was prepared
  2. customwas removed by distillation at atmospheric pressure (head temperature 125° C.) over a 1 h period
  3. customThe remaining acetic anhydride was removed at 50° C./0.5 mm
  4. customthe residual liquid was crystallized from ether (150 mL) at -20° C.

Sources & evidence

ORD record
ord-ea9ec46cac0b406688e4ee3afe086f75
Source dataset
uspto-grants-1992_03
Patent number
US05100909

Reaction notes

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