Dimethyl Sulfate → 6-Benzoyl-1-methyl-2-(2-pyridylsulfinylmethyl)benzimidazole

HRID 414191Notes

Reaction equation

HRID 414191 reaction equation
[C:1]([C:9]1[CH:26]=[CH:25][C:12]2[N:13]=[C:14]([CH2:16][S:17]([C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][N:20]=3)=[O:18])[NH:15][C:11]=2[CH:10]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[Na+].S(OC)(O[CH3:33])(=O)=O>C(O)C.O>[C:1]([C:9]1[CH:26]=[CH:25][C:12]2[N:13]([CH3:33])[C:14]([CH2:16][S:17]([C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][N:20]=3)=[O:18])=[N:15][C:11]=2[CH:10]=1)(=[O:8])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1.[C:1]([C:9]1[CH:26]=[CH:25][C:12]2[N:13]=[C:14]([CH2:16][S:17]([C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][N:20]=3)=[O:18])[N:15]([CH3:33])[C:11]=2[CH:10]=1)(=[O:8])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

7

Reactant 3

HCID 6497Dimethyl SulfateHCID 14798Sodium HydroxideHCID 139611705-Benzoyl-2-(2-pyridylsulfinylmethyl)benzimidazole

Product 2

HCID 139611875-Benzoyl-1-methyl-2-(2-pyridylsulfinylmethyl)benzimidazoleYield 12.5%HCID 139611886-Benzoyl-1-methyl-2-(2-pyridylsulfinylmethyl)benzimidazoleYield 40%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A mixture of 3.61 g of 5-benzoyl-2-(2-pyridylsulfinylmethyl)benzimidazole (0.01 mole), 0.40 g of sodium hydroxide (0.01 mole) and 2 ml of dimethyl sulfate (0.02 mole) in 50 ml of ethanol and 5 ml of water is maintained under reflux for 3 hours. The ethanol is evaporated off and the residue diluted with water and extracted with chloroform. The organic phase is washed with water, dried and evaporated. The residue is chromatographed with silica gel, using chloroform/methanol (99:1) and subsequently chloroform/methanol (95:5) as eluant. On fractional crystallization of the final fraction in ethyl acetate, 0.47 g (12.5%) of 5-benzoyl-1-methyl-2-(2-pyridylsulfinylmethyl)benzimidazole, melting point 174°-177° C., and 1.5 g (40%) of 6-benzoyl-1-methyl-2-(2-pyridylsulfinylmethyl)benzimidazole, melting point 181°-183° C., are obtained.

Workup

  1. temperatureis maintained
  2. temperatureunder reflux for 3 hours
  3. customThe ethanol is evaporated off
  4. additionthe residue diluted with water
  5. extractionextracted with chloroform
  6. washThe organic phase is washed with water
  7. customdried
  8. customevaporated
  9. customThe residue is chromatographed with silica gel
  10. customOn fractional crystallization of the final fraction in ethyl acetate

Sources & evidence

ORD record
ord-b6f700a299384ce38dc192de4a8234d1
Source dataset
uspto-grants-1988_12
Patent number
US04791114

Reaction notes

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