Imidazole → Triphenylphosphine Oxide

HRID 278136Notes

Reaction equation

HRID 278136 reaction equation
N1C=CN=C1.[C:6]1([P:12]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.II.CC[O:29]CC>C(Cl)Cl>[C:19]1([P:12](=[O:29])([C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=1

Participants

6

Reactant 4

HCID 795ImidazoleHCID 807IodineHCID 3283Diethyl EtherHCID 11776Triphenylphosphine

Product 1

HCID 13097Triphenylphosphine Oxide

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-2 °C

Procedure

A 12-L, three-neck, round-bottom flask equipped with a mechanical stirrer, thermocouple, nitrogen bubbler, and an additional funnel, was charged with imidazole (204 g, 2.99 mol, 6.0 equivalents), triphenylphosphine (300 g, 1.14 mol, 2.3 equivalents), and methylene chloride (2.5 L). The resulting solution was cooled to −2° C. and to this was added iodine (290 g, 1.14 mol, 2.3 equivalents). The resulting mixture was allowed to stir for 15 minutes, and then a solution of (12) (274 g, 0.50 mol) in methylene chloride (1.3 L) was added slowly, over 35 minutes. The resulting orange mixture was allowed to warm to room temperature where it was stirred for three hours. The reaction mixture was filtered, and the filtrate was washed successively with 2% aqueous sodium sulfite solution (1×2 L), 0.1 N aqueous hydrochloric acid solution (1×1.5 L), and saturated aqueous sodium chloride solution (1×1.5 L). The organics were then dried over anhydrous magnesium sulfate and filtered. The solvent was removed in vacuo to afford a yellow residue which was dissolved in ether (4 L) producing a white precipitate (triphenylphosphine oxide). The solution was filtered and the filtrate was evaporated in vacuo to afford 320 g of (13) as a yellow oil contaminated with triphenylphosphine oxide. This material was used in the next step without purification.

Workup

  1. temperatureto warm to room temperature where it
  2. stirringwas stirred for three hours
  3. filtrationThe reaction mixture was filtered
  4. washthe filtrate was washed successively with 2% aqueous sodium sulfite solution (1×2 L), 0.1 N aqueous hydrochloric acid solution (1×1.5 L), and saturated aqueous sodium chloride solution (1×1.5 L)
  5. dry with materialThe organics were then dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customThe solvent was removed in vacuo
  8. customto afford a yellow residue which

Sources & evidence

ORD record
ord-584ef058110e4e49985fd810c0dbc368
Source dataset
uspto-grants-2002_03
Patent number
US06359012B1

Reaction notes

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