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

HRID 2064639Notes

Reaction equation

HRID 2064639 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-2c031dae5d8a457082afe7de448a6b4c
Source dataset
uspto-grants-2012_10
Patent number
US08288425B2

Reaction notes

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