Acetic Acid → 2-Aminobenzimidazole

HRID 893689

Reaction equation

HRID 893689 reaction equation
FC1C=CC(C[N:9]2[C:13]3[CH:14]=[CH:15][CH:16]=[CH:17][C:12]=3[N:11]=[C:10]2[NH:18]C2CCNCC2)=CC=1.C(O)(=O)C.CC1N=C2C=CC=CN2C=1.[OH-].[Na+]>O>[NH:9]1[C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][C:12]=2[N:11]=[C:10]1[NH2:18]

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 14798Sodium HydroxideHCID 123618TecastemizoleHCID 1367422-Methylimidazo[1,2-a]pyridineHCID 178486302HCID 178486302, compound

Product 1

HCID 136242-Aminobenzimidazole

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

To a stirred and cooled (0° C.) mixture of 3.8 parts of poly(oxymethylene) 37%, 15.5 parts of 1-[(4-fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-amine and 7 parts of glacial acetic acid were added 6.5 parts of 2-methylimidazo[1,2-a]pyridine under nitrogen atmosphere. The whole was heated slowly to 50° C. and stirring was continued at 50° C. for 2 hours. After stirring was continued overnight at room temperature, the reaction mixture was poured into water and the whole was made alkaline with sodium hydroxide. The product was extracted with dichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol, saturated with ammonia, (96:4 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from acetonitrile. The product was filtered off and dried, yielding 6.7 parts (30%) of 1-[(4-fluorophenyl)methyl]-N-[(2-methylimidazo[1,2-a]pyridin-3-yl)methyl]-4-piperidinyl]-1H-benzimidazol-2-amine; mp. 198.1° C. (compound 106).

Workup

  1. temperaturecooled
  2. stirringstirring
  3. stirringAfter stirring
  4. waitwas continued overnight at room temperature
  5. extractionThe product was extracted with dichloromethane
  6. customThe extract was dried
  7. filtrationfiltered
  8. customevaporated
  9. customThe residue was purified by column chromatography over silica gel using
  10. additiona mixture of trichloromethane and methanol
  11. customThe pure fractions were collected
  12. customthe eluent was evaporated
  13. customThe residue was crystallized from acetonitrile
  14. filtrationThe product was filtered off
  15. customdried

Sources & evidence

ORD record
ord-75dc6652050743c8a61d2ed24b2ba07f
Source dataset
uspto-grants-1992_06
Patent number
US05126339

Linked notes

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