Sulfuric Acid → 5-Benzoyl-1-isopropyl-2-methylimidazole

HRID 2267188Notes

Reaction equation

HRID 2267188 reaction equation
[CH:1]([NH:4][C:5](=[NH:7])[CH3:6])([CH3:3])[CH3:2].Br[C:9](=[CH:18]OC)[C:10]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:11].C(N(CC)CC)C.S(=O)(=O)(O)O>C(O)(C)C>[C:10]([C:9]1[N:4]([CH:1]([CH3:3])[CH3:2])[C:5]([CH3:6])=[N:7][CH:18]=1)(=[O:11])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 8471TriethylamineHCID 866370402-Bromo-3-methoxy-1-phenyl-2-propen-1-oneHCID 178465597HCID 178465597, compound

Product 1

HCID 160398465-Benzoyl-1-isopropyl-2-methylimidazoleYield 10%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Conditions

Temperature
80 °C

Procedure

In a 300 mL-volume glass vessel equipped with a stirrer, a thermometer and a dropping funnel, the isopropyl alcohol solution containing 16.2 g (0.162 mol) of N-isopropylacetamidine (which was prepared in the same manner as in Reference Example 1), 26.0 g (0.108 mol) of 2-bromo-3-methoxy-1-phenyl-2-propen-1-one and 16.4 g (0.162 mol) of triethylamine were placed. The mixture was heated to 80° C. under stirring for 8 hours for carrying out reaction. After the reaction was complete, 80 mL of sulfuric acid (2 mol/L) was added to the reaction mixture, and the mixture was concentrated under reduced pressure. The concentrate was washed with methyl isobutyl ketone, and the aqueous portion was taken out. The aqueous portion was made basic by adding an aqueous 48% sodium hydroxide, while the mixture was kept at a temperature of not higher than 40° C. The aqueous basic portion was subjected to extraction with methyl isobutyl ketone, and the extracted portion was concentrated under reduced pressure. The concentrate was purified by silica gel column chromatography (eluant: hexane/ethyl acetate=2/1) to give 2.47 g (yield: 10%) of 5-benzoyl-1-isopropyl-2-methylimidazole as pale yellow liquid.

Workup

  1. customIn a 300 mL-volume glass vessel equipped with a stirrer
  2. customreaction
  3. concentrationthe mixture was concentrated under reduced pressure
  4. washThe concentrate was washed with methyl isobutyl ketone
  5. additionby adding an aqueous 48% sodium hydroxide
  6. customhigher than 40° C
  7. extractionThe aqueous basic portion was subjected to extraction with methyl isobutyl ketone
  8. concentrationthe extracted portion was concentrated under reduced pressure
  9. customThe concentrate was purified by silica gel column chromatography (eluant: hexane/ethyl acetate=2/1)

Sources & evidence

ORD record
ord-a1c8368a0cba4009b270323bda0b7a9f
Source dataset
uspto-grants-2010_12
Patent number
US07858807B2

Reaction notes

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