Triethylamine → ethyl 1-benzyl-1H-imidazole-2-carboxylate

HRID 2074065Notes

Reaction equation

HRID 2074065 reaction equation
[CH2:1]([N:8]1[CH:12]=[CH:11][N:10]=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.Cl[C:21]([O:23][CH2:24][CH3:25])=[O:22]>C(#N)C>[CH2:1]([N:8]1[CH:12]=[CH:11][N:10]=[C:9]1[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 10928Ethyl chloroformateHCID 779181-Benzylimidazole

Product 1

HCID 39869052ethyl 1-benzyl-1H-imidazole-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
-20 °C

Procedure

148 g (936 mmol) of 1-benzyl-1H-imidazole are suspended in 480 ml of acetonitrile and, at −20° C., 120 ml (87.1 g; 860 mmol) of triethylamine are added. Over a period of 15 minutes, 211.2 ml (239 g; 2208 mmol) of ethyl chloroformate are then added dropwise. The reaction mixture is stirred at −20° C. for 10 minutes. After warming to 15 to 20° C., the reaction mixture is stirred for 18 h and then concentrated in vacuo. Water, a saturated sodium chloride solution and a saturated sodium bicarbonate solution are added to the residue, and the mixture is extracted three times with ethyl acetate. The combined organic phases are washed with a saturated sodium chloride solution and, after drying with magnesium sulfate, concentrated in vacuo. The residue is subjected to a fractional distillation under high vacuum (boiling point=173 to 181° C., pressure=1.7 to 1.2 mbar).

Workup

  1. temperatureAfter warming to 15 to 20° C.
  2. stirringthe reaction mixture is stirred for 18 h
  3. concentrationconcentrated in vacuo
  4. additionWater, a saturated sodium chloride solution and a saturated sodium bicarbonate solution are added to the residue
  5. extractionthe mixture is extracted three times with ethyl acetate
  6. washThe combined organic phases are washed with a saturated sodium chloride solution
  7. dry with materialafter drying with magnesium sulfate
  8. concentrationconcentrated in vacuo
  9. distillationThe residue is subjected to a fractional distillation under high vacuum (boiling point=173 to 181° C., pressure=1.7 to 1.2 mbar)

Sources & evidence

ORD record
ord-271f70d6d38b412b852fdbb898c72a35
Source dataset
uspto-grants-2011_04
Patent number
US07919489B2

Reaction notes

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