Hydrochloric Acid → 1-{3-[4-(4-fluorobenzoyl)-1-piperidinyl]propyl}-1,3-dihydro-6-methyl-2H-benzimidazol-2-one

HRID 258860Notes

Reaction equation

HRID 258860 reaction equation
[F:1][C:2]1[CH:32]=[CH:31][C:5]([C:6]([CH:8]2[CH2:13][CH2:12][N:11]([CH2:14][CH2:15][CH2:16][N:17]3[C:21]4[CH:22]=[C:23]([CH3:26])[CH:24]=[CH:25][C:20]=4[N:19](C(C)=C)[C:18]3=[O:30])[CH2:10][CH2:9]2)=[O:7])=[CH:4][CH:3]=1.Cl.C(O)C>O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([CH:8]2[CH2:13][CH2:12][N:11]([CH2:14][CH2:15][CH2:16][N:17]3[C:21]4[CH:22]=[C:23]([CH3:26])[CH:24]=[CH:25][C:20]=4[NH:19][C:18]3=[O:30])[CH2:10][CH2:9]2)=[O:7])=[CH:31][CH:32]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 702EthanolHCID 214248083-{3-[4-(4-fluorobenzoyl)-1-piperidinyl]propyl}-1,3-dihydro-5-methyl-1-(1-methylethenyl)-2H-benzimidazol-2-one

Product 1

HCID 214248311-{3-[4-(4-fluorobenzoyl)-1-piperidinyl]propyl}-1,3-dihydro-6-methyl-2H-benzimidazol-2-oneYield 25%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 4.5 parts of 3-{3-[4-(4-fluorobenzoyl)-1-piperidinyl]propyl}-1,3-dihydro-5-methyl-1-(1-methylethenyl)-2H-benzimidazol-2one, 24 parts of a concentrated hydrochloric acid solution, 80 parts of ethanol and 50 parts of water is stirred for 2 hours at room temperature. The reaction mixture is evaporated and the residue is stirred in water. The whole is alkalized with ammonium hydroxide. The product is extracted with trichloromethane. The extract is dried, filtered and evaporated. The oily residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions are collected and the eluent is evaporated. The residue is crystallized from 4-methyl-2-pentanone, yielding 1 part (25%) of 1-{3-[4-(4-fluorobenzoyl)-1-piperidinyl]propyl}-1,3-dihydro-6-methyl-2H-benzimidazol-2-one; mp. 149.7° C

Workup

  1. customThe reaction mixture is evaporated
  2. stirringthe residue is stirred in water
  3. extractionThe product is extracted with trichloromethane
  4. customThe extract is dried
  5. filtrationfiltered
  6. customevaporated
  7. customThe oily residue is purified by column-chromatography over silica gel using
  8. additiona mixture of trichloromethane and methanol (95:5 by volume) as eluent
  9. customThe pure fractions are collected
  10. customthe eluent is evaporated
  11. customThe residue is crystallized from 4-methyl-2-pentanone

Sources & evidence

ORD record
ord-5b58f190be924044a2c34867843efe5e
Source dataset
uspto-grants-1977_07
Patent number
US04035369

Reaction notes

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