Triethylamine → 2-((4-(2-Pyridinyl)-1-piperazinyl)methyl)-1H-benzimidazole

HRID 898710Notes

Reaction equation

HRID 898710 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[N:7]1[CH2:12][CH2:11][NH:10][CH2:9][CH2:8]1.Cl[CH2:14][C:15]1[NH:16][C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[N:19]=1.C(N(CC)CC)C>CN(C=O)C>[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[N:7]1[CH2:8][CH2:9][N:10]([CH2:14][C:15]2[NH:19][C:18]3[CH:20]=[CH:21][CH:22]=[CH:23][C:17]=3[N:16]=2)[CH2:11][CH2:12]1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 785712-ChloromethylbenzimidazoleHCID 944591-(2-Pyridyl)piperazine

Product 1

HCID 50257392-((4-(2-Pyridinyl)-1-piperazinyl)methyl)-1H-benzimidazoleYield 85.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a rapidly stirred solution of 1-(2-pyridyl)piperazine (5.9 g, 36 mmol) in DMF (15 mL) in a large round bottom flask in a water bath at 20° C. was added 2-chloromethylbenzimidazole powder (6 g, 36 mmol) over 2 minutes. Triethylamine (7.5 mL, 1.5 eq) was added, and the reaction was stirred for 16 hours, until TLC indicated complete consumption of starting material. The reaction was then treated with 5 mL of triethylamine followed by the slow dropwise addition of water (70 mL). After one hour, the precipitate was collected by suction filtration and washed with 400 mL of water and dried to give 9 grams of product. The solid was recrystallized twice from boiling n-butanol to give 7.6 grams (72% yield purified) of the title compound as a buff powder. mp 220-221° C. 1H NMR (d6-DMSO, 300 MHz) δ 2.55 (4H, J=4.5 Hz), 3.52 (4H, J=4.5 Hz), 3.77 (s, 2H), 6.62 (1H, J=6.6, 4.5 Hz), 6.81 (1H, J=8.7 Hz), 7.14 (2H, m), 7.41-7.58 (3H, m), 8.09 (1H, J=4.5, 1.8 Hz). MS (DCI/NH3) m/z 294 (M+H)+. Anal. Calcd for C17H19N5: C, 69.60; H, 6.53; N, 23.87. Found: C, 69.47; H, 6.58; N, 23.87.

Workup

  1. customconsumption of starting material
  2. additionThe reaction was then treated with 5 mL of triethylamine
  3. additionfollowed by the slow dropwise addition of water (70 mL)
  4. waitAfter one hour
  5. filtrationthe precipitate was collected by suction filtration
  6. washwashed with 400 mL of water
  7. customdried

Sources & evidence

ORD record
ord-46a82a57a202498ea21b61bcd360eaf1
Source dataset
uspto-grants-2008_04
Patent number
US07351828B2

Reaction notes

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