3,4-dihydro-2H-pyran → 5-bromo-4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole

HRID 475092Notes

Reaction equation

HRID 475092 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:9]=[CH:8][NH:7][C:6]=2[C:10]=1[O:11][CH3:12].[O:13]1[CH:18]=[CH:17][CH2:16][CH2:15][CH2:14]1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>CCOC(C)=O>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:9]([CH:14]3[CH2:15][CH2:16][CH2:17][CH2:18][O:13]3)[CH:8]=[N:7][C:6]=2[C:10]=1[O:11][CH3:12]

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 1784863775-bromo-4-methoxy-1H-benzimidazole

Product 1

HCID 712726975-bromo-4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazoleYield 60.3%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
90 °C

Procedure

A 500 ml tube was charged with 6-bromo-7-methoxy-1H-benzoimidazole (36 g, 0.16 mol, 1.0 equiv.), dihydropyran (40.01 g, 0.48 mol, 3.0 equiv.) and pyridinium-p-toluenesulfonate (7.96 g, 0.032 mol, 0.2 equiv.) in EtOAc (400 mL), sealed and the reaction mixture was heated at 90° C. overnight. The reaction mixture was concentrated in vacuo and the crude product was purified by SiO2 chromatography eluting with an EtOAc/hexane gradient (30-40% EtOAc) to afford 5-bromo-4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole (30 g, 60% yield) as a brown solid.

Workup

  1. customsealed
  2. concentrationThe reaction mixture was concentrated in vacuo
  3. customthe crude product was purified by SiO2 chromatography
  4. washeluting with an EtOAc/hexane gradient (30-40% EtOAc)

Sources & evidence

ORD record
ord-670a662313c846e4a66dca91aeb5c095
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

Loading…