Fumaric Acid → 1-Ethyl-N-(1-methyl-3-pyrrolidinyl)-1H-benzimidazol-2-amine

HRID 1030505Notes

Reaction equation

HRID 1030505 reaction equation
Cl[C:2]1[N:6]([CH2:7][CH3:8])[C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[N:3]=1.[NH2:13][CH:14]1[CH2:18][CH2:17][N:16]([CH3:19])[CH2:15]1.C(O)(=O)/C=C/C(O)=O>C(O)CCC.C(O)(C)C.O>[CH2:7]([N:6]1[C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[N:3]=[C:2]1[NH:13][CH:14]1[CH2:18][CH2:17][N:16]([CH3:19])[CH2:15]1)[CH3:8]

Participants

7

Reactant 3

HCID 444972Fumaric AcidHCID 37447962-chloro-1-ethyl-1H-1,3-benzodiazoleHCID 189403961-Methylpyrrolidin-3-amine

Product 1

HCID 198206601-Ethyl-N-(1-methyl-3-pyrrolidinyl)-1H-benzimidazol-2-amineYield 63%

Reagents, catalysts & solvents 3

HCID 2631-ButanolSolventHCID 962WaterSolventHCID 3776IsopropanolSolvent

Procedure

A solution of 38.6 g (0.21 mol) of 2-chloro-1-ethylbenzimidazole and 24 g (0.24 mol) of 3-amino-1-methylpyrrolidine in 150 mL of n-butanol was heated to reflux for 72 h and concentrated on the rotary evaporator (70° C./30 mm). The residue was partitioned between CHCl3 and dilute NaOH. The CHCl3 solution was dried (Na2SO4) and concentrated. For purification the material obtained was converted to the difumarate salt. The residue (68 g) was treated with a boiling solution of 64 g of fumaric acid in 600 mL of isopropyl alcohol and 100 mL of H2O. The resulting salt weighted 48 g (63% yield). A sample was recrystallized from ethanol-H2O, mp 204°-212° C. (dec).

Workup

  1. temperatureto reflux for 72 h
  2. concentrationconcentrated on the rotary evaporator (70° C./30 mm)
  3. customThe residue was partitioned between CHCl3 and dilute NaOH
  4. dry with materialThe CHCl3 solution was dried (Na2SO4)
  5. concentrationconcentrated
  6. customFor purification the material
  7. customobtained
  8. customA sample was recrystallized from ethanol-H2O, mp 204°-212° C. (dec)

Sources & evidence

ORD record
ord-ea5da389261548618cadabe2b7e03535
Source dataset
uspto-grants-1992_04
Patent number
US05106857

Reaction notes

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