p-Toluenesulfonic acid → 2-Acetyl-1-(tetrahydropyran-2-yl)-benzoimidazole

HRID 2182385Notes

Reaction equation

HRID 2182385 reaction equation
[O:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.[C:7]([C:10]1[NH:11][C:12]2[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=2[N:14]=1)(=[O:9])[CH3:8].C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl>[C:7]([C:10]1[N:11]([CH:6]2[CH2:5][CH2:4][CH2:3][CH2:2][O:1]2)[C:12]2[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=2[N:14]=1)(=[O:9])[CH3:8]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 703221-(1H-Benzimidazol-2-yl)ethanone

Product 1

HCID 224780482-Acetyl-1-(tetrahydropyran-2-yl)-benzoimidazole

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Dihydropyran (20.5 mL) as added dropwise to a solution of 2-acetylbenzoimidazole (32 g) and p-toluenesulfonic acid (2 g) in dichloromethane (280 mL) at reflux. The reaction mixture was stirred at this temperature for 24 hours, then cooled and the insoluble materials were filtered off. The filtrate was concentrated to give 2-acetyl-1-(tetrahydropyran-2-yl)-benzoimidazole as an amber oil (51.8 g). TLC: dichloromethane:methanol, 97:3) RF=0.80.

Workup

  1. temperatureat reflux
  2. temperaturecooled
  3. filtrationthe insoluble materials were filtered off
  4. concentrationThe filtrate was concentrated

Sources & evidence

ORD record
ord-849ae94215db4f2a9a972fed8cca19ba
Source dataset
uspto-grants-2005_05
Patent number
US06897208B2

Reaction notes

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