1-Bromo-3-chloropropane → 1-(3-Chloropropyl)-1,3-dihydro-3-(1-methylvinyl)-2H-benzimidazol-2-one

HRID 1833633Notes

Reaction equation

HRID 1833633 reaction equation
[CH3:1][C:2]([N:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[NH:6][C:5]1=[O:13])=[CH2:3].[H-].[Na+].Br[CH2:17][CH2:18][CH2:19][Cl:20]>CN(C)C=O>[Cl:20][CH2:19][CH2:18][CH2:17][N:6]1[C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=2[N:4]([C:2]([CH3:1])=[CH2:3])[C:5]1=[O:13]

Participants

5

Reactant 3

HCID 80061-Bromo-3-chloropropaneHCID 24758Sodium hydrideHCID 1002781,3-Dihydro-1-(1-methylvinyl)-2H-benzimidazol-2-one

Product 1

HCID 30173591-(3-Chloropropyl)-1,3-dihydro-3-(1-methylvinyl)-2H-benzimidazol-2-oneYield 44%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a stirred solution of 8.5 parts of 1,3-dihydro-1-(1-methylethenyl)-2H-benzimidazol-2-one in 45 parts of N,N-dimethylformamide are added portionwise 1.7 parts of a sodium hydride dispersion 78%. After stirring for 1 hour at room temperature, the whole is cooled to 0-5° C and 8.65 parts of 1-bromo-3-chloropropane are added dropwise (slowly). Upon completion, stirring is continued for 3 hours at room temperature. The reaction mixture is poured into crushed ice and the product is extracted with methylbenzene. The extract is washed with water, dried, filtered and evaporated. The residue is crystallized from 2-propanol, yielding 5.5 parts (44%) of 1-(3-chloropropyl)-1,3-dihydro-3-(1-methylethenyl)2H-benzimidazol-2-one; mp. 115° C.

Workup

  1. temperaturethe whole is cooled to 0-5° C
  2. stirringUpon completion, stirring
  3. waitis continued for 3 hours at room temperature
  4. additionThe reaction mixture is poured
  5. custominto crushed ice
  6. extractionthe product is extracted with methylbenzene
  7. washThe extract is washed with water
  8. customdried
  9. filtrationfiltered
  10. customevaporated
  11. customThe residue is crystallized from 2-propanol

Sources & evidence

ORD record
ord-ed311bf913c148fb8a69cc9d037941b1
Source dataset
uspto-grants-1978_01
Patent number
US04066772

Reaction notes

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