Acetic Anhydride → Acetate

HRID 8908Notes

Reaction equation

HRID 8908 reaction equation
[OH:1][CH2:2][C:3]1[N:4]([CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:5]([CH2:8][OH:9])=[CH:6][N:7]=1.C(N(CC)CC)C.[C:24]([O:27]C(=O)C)(=[O:26])[CH3:25]>ClCCl>[CH3:25][C:24]([O-:27])=[O:26].[C:24]([O:1][CH2:2][C:3]1[N:4]([CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:5]([CH2:8][OH:9])=[CH:6][N:7]=1)(=[O:26])[CH3:25]

Participants

6

Reactant 3

HCID 7918Acetic AnhydrideHCID 8471TriethylamineHCID 143167542,5-bis-(hydroxymethyl)-N-benzylimidazole

Product 2

HCID 175AcetateHCID 686179892-acetoxymethyl-5-hydroxymethyl-N-benzylimidazole

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2,5-bis-(hydroxymethyl)-N-benzylimidazole (436 mg, 2.0 mmol) in dichloromethane (10 mL) was added triethylamine (0.35 mL, 2.0 mmol) and acetic anhydride (0.19 mL, 2.0 mmol). The mixture was then stirred overnight (16 h) at room temperature. The reaction was then washed with aqueous ammonium chloride and the layers separated. The aqueous layer was extracted twice with dichloromethane. The combined organic fractions were then dried over anhydrous sodium sulfate and concentrated. Purification by chromatography on silica gel (5% methanol in dichloromethane) gave the monoacetate, 2-acetoxymethyl-5-hydroxymethyl-N-benzylimidazole, as a white powder (300 mg, 58%). 1H NMR (CDCl3) δ 1.83 (s, 3H), 4.49 (s, 2H), 5.06 (s, 2H), 5.33 (s, 2H), 6.97 (m, 2H), 7.28 (m, 3H).

Workup

  1. washThe reaction was then washed with aqueous ammonium chloride
  2. customthe layers separated
  3. extractionThe aqueous layer was extracted twice with dichloromethane
  4. dry with materialThe combined organic fractions were then dried over anhydrous sodium sulfate
  5. concentrationconcentrated
  6. customPurification by chromatography on silica gel (5% methanol in dichloromethane)

Sources & evidence

ORD record
ord-ed26296c2ba1419eac674707956ad926
Source dataset
uspto-grants-2006_08
Patent number
US07091217B2

Reaction notes

Loading…