Water → 1-Benzyl-2-chlorobenzimidazole

HRID 1030506Notes

Reaction equation

HRID 1030506 reaction equation
[Cl:1][C:2]1[NH:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.[H-].[Na+].[CH2:13](Br)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.O>CN(C)C=O>[CH2:13]([N:3]1[C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=[C:2]1[Cl:1])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 785722-Chlorobenzimidazole

Product 1

HCID 38219871-Benzyl-2-chlorobenzimidazole

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A solution of 2-chlorobenzimidazole (100 g, 0.65 mol) in 500 ml of dimethylformamide (DMF) was added dropwise to a stirred suspension of 60% sodium hydride-mineral oil dispersion (28 g, 0.70 mol) in 500 ml of DMF. Mild intermittent cooling was required. After the addition was completed the mixture was stirred an additional 15 min and benzylbromide (82.6 g, 0.49 mol) was added dropwise with mild intermittent cooling. The reaction mixture was stirred an additional 1.5 h and 1 L of water was added. The mixture was extracted with benzene. The extract was dried (Na2SO4), concentrated and the residue crystallized from isopropyl ether to obtain 110 g (93%), mp 102°-105° C.

Workup

  1. temperatureMild intermittent cooling
  2. additionAfter the addition
  3. stirringThe reaction mixture was stirred an additional 1.5 h
  4. extractionThe mixture was extracted with benzene
  5. dry with materialThe extract was dried (Na2SO4)
  6. concentrationconcentrated
  7. customthe residue crystallized from isopropyl ether
  8. customto obtain 110 g (93%), mp 102°-105° C.

Sources & evidence

ORD record
ord-b913f8cf02f04b009cfcce06ca99d9ff
Source dataset
uspto-grants-1992_04
Patent number
US05106857

Reaction notes

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