Sodium hydride → 2,4,5,6,7-Pentachloro-1-(2-benzyloxyethoxymethyl)benzimidazole

HRID 1900128Notes

Reaction equation

HRID 1900128 reaction equation
[H-].[Na+].[Cl:3][C:4]1[NH:5][C:6]2[C:12]([Cl:13])=[C:11]([Cl:14])[C:10]([Cl:15])=[C:9]([Cl:16])[C:7]=2[N:8]=1.[CH2:17]([O:24][CH2:25][CH2:26][O:27][CH2:28]Cl)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>CC#N>[Cl:3][C:4]1[N:5]([CH2:28][O:27][CH2:26][CH2:25][O:24][CH2:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C:6]2[C:12]([Cl:13])=[C:11]([Cl:14])[C:10]([Cl:15])=[C:9]([Cl:16])[C:7]=2[N:8]=1

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 10998043BenzyloxyethoxymethylchlorideHCID 232739742,4,5,6,7-pentachloro-1H-benzimidazole

Product 1

HCID 186975622,4,5,6,7-Pentachloro-1-(2-benzyloxyethoxymethyl)benzimidazoleYield 38.4%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent2×

Procedure

NaH (0.033 g, 1.52 mmole, 90% oil dispersion) was added to a stirred suspension of 2,4,5,6,7-pentachlorobenzimidazole (14) (0.3 g, 1.03 mmole) in dry CH3CN (35 mL) under a N2 atmosphere. The solution was stirred until H2 evolution had ceased and a clear solution was obtained (20 min.). (2-Benzyloxyethoxy)methylchloride (0.31 g, 1.54 mmole) in CH3CN (10 mL) was then added dropwise. The reaction mixture was stirred for an additional 15 hr. The resulting mixture was concentrated under reduced pressure, diluted with H2O (50 mL), extracted with EtOAc (100 mL), washed with H2O (100 mL), dried (anhyd. Na2SO4) and the solvent was removed under reduced pressure to yield an oil. The resulting oil was purified by flash column chromatography (2×24 cm) (230-400 mesh). Elution of the column with hexane:EtOAc (6:4, v/v) and evaporation of the appropriate fractions followed by crystallization from hexane:EtOAc afforded 0.18 g (38.4%) of blocked product: m.p. 95° C.; 1H NMR (CDCl3): d 7.22-7.34 (m, 5H, C6H5), 5.93 (s, 2H, C-1'), 4.47 (s, 2H, CH2C6H5), 3.70-3.73 (m, 2H, C-3'), 3.45-3.57 (m, 2H, C-4'), 1.83 (s, 3H, Ac). Anal. Calcd. for C17H13NCl5O2 : C, 44.88; H, 2.86; N, 6.16. Found: C, 44.95; H, 2.59; N, 6.05.

Workup

  1. customa clear solution was obtained (20 min.)
  2. stirringThe reaction mixture was stirred for an additional 15 hr
  3. concentrationThe resulting mixture was concentrated under reduced pressure
  4. additiondiluted with H2O (50 mL)
  5. extractionextracted with EtOAc (100 mL)
  6. washwashed with H2O (100 mL)
  7. dry with materialdried (anhyd. Na2SO4)
  8. customthe solvent was removed under reduced pressure
  9. customto yield an oil
  10. customThe resulting oil was purified by flash column chromatography (2×24 cm) (230-400 mesh)
  11. washElution of the column
  12. customwith hexane:EtOAc (6:4, v/v) and evaporation of the appropriate fractions
  13. customfollowed by crystallization from hexane

Sources & evidence

ORD record
ord-40f0cf5fb0704908950f77729d8755bf
Source dataset
uspto-grants-1996_11
Patent number
US05574058

Reaction notes

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