Ethylene Glycol → HCID 178526574, compound

HRID 843232Notes

Reaction equation

HRID 843232 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[C:10]1[NH:11][C:12]2[C:18]([CH:19]=[O:20])=[CH:17][CH:16]=[CH:15][C:13]=2[N:14]=1)([O-:3])=[O:2].[CH2:21](O)[CH2:22][OH:23].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH2:22]1[O:23][CH:19]([C:18]2[C:12]3[NH:11][C:10]([C:5]4[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=4[N+:1]([O-:3])=[O:2])=[N:14][C:13]=3[CH:15]=[CH:16][CH:17]=2)[O:20][CH2:21]1

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 521998p-Toluenesulfonic acid monohydrateHCID 178519437HCID 178519437, compound

Product 1

HCID 178526574HCID 178526574, compoundYield 62.2%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

2-(2-Nitrophenyl)-benzimidazole-4-carboxaldehyde 4 (6.27 g, 23.5 mmol) was dissolved in benzene (150 mL), and mixed with ethylene glycol (6.5 mL, 118 mmol) and p-toluenesulfonic acid monohydrate (0.450 g, 2.35 mmol). The mixture was heated to reflux overnight and the water was removed by azeotropic distillation. The resulting solution was allowed to cool to room temperature, and was then neutralized with saturated NaHCO3, washed with water and brine and dried over Na2SO4. The compound was purified by column chromatography on silica gel using hexane/ethyl acetate (1:2) as the eluent to give 2-(2-nitrophenyl)-benzimidazole-4-carboxaldehyde ethylene acetal (4.552 g, 62.2%) as a yellow solid. Rf=0.24 (hexane/ethyl acetate=1:2); 1H NMR (200 MHz, CDCl3) δ 4.11 (m, 2H), 4.20 (m, 2H), 6.15 (s, 1H), 7.30 (m, 2H), 7.57-7.83 (m, 3H), 7.93 (d, J1=7.8 Hz, J2=1.3 Hz, 1H), 8.13 (d, J1=7.7 Hz, J2=1.5 Hz, 1H), 10.48 (broad s, 1H). HRMS: Calcd. for C16H13N3O4 311.0906, found 311.0915.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux overnight
  3. customthe water was removed by azeotropic distillation
  4. washwashed with water and brine
  5. dry with materialdried over Na2SO4
  6. customThe compound was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-7e3290761e1c4a779c65d4965ccfba65
Source dataset
uspto-grants-2002_04
Patent number
US06376664B1

Reaction notes

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