1-(2-Trimethylsilylethoxymethyl)-2-hydroxymethylbenzimidazole → 1-(2-Trimethylsilylethoxymethyl)-2-formyl-benzimidazole

HRID 1624228Notes

Reaction equation

HRID 1624228 reaction equation
[CH3:1][Si:2]([CH3:19])([CH3:18])[CH2:3][CH2:4][O:5][CH2:6][N:7]1[C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[N:9]=[C:8]1[CH2:16][OH:17]>C(Cl)Cl.O=[Mn]=O>[CH3:1][Si:2]([CH3:19])([CH3:18])[CH2:3][CH2:4][O:5][CH2:6][N:7]1[C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[N:9]=[C:8]1[CH:16]=[O:17]

Participants

4

Reactant 1

HCID 226099341-(2-Trimethylsilylethoxymethyl)-2-hydroxymethylbenzimidazole

Product 1

HCID 120171281-(2-Trimethylsilylethoxymethyl)-2-formyl-benzimidazoleYield 55%

Reagents, catalysts & solvents 2

HCID 14801Manganese dioxideCatalystHCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of the alcohol from above (26.58 g, 0.096 mol) in dry CH2Cl2 (450 mL) was added activated MnO2 (<5 micron, ˜85%, 93 g, 0.91 mol) and the suspension stirred at room temperature overnight. The mixture was filtered through Celite© (175 g) and the cake was washed with CH2Cl2. The solvent was removed from the eluent under reduced pressure and the resultant residue purified by column chromatography on silica gel (3% MeOH/CH2Cl2) to provide the title aldehyde (14.41 g, 55%) as a pale yellow oil. 1H NMR (CDCl3) δ −0.07 (s, 9H), 0.90 (t, 2H, J=9 Hz), 3.56 (t, 2H, J=9 Hz), 6.04 (s, 2H), 7.43-7.51 (m, 2H), 7.66 (d, 1H, J=9 Hz), 7.95 (d, 1H, J=9 Hz), 10.13 (s, 1H); 13C NMR (CD3OD) δ −1.19, 17.94, 66.62, 73.30, 112.22, 122.51, 124.64, 127.43, 136.62, 143.11, 146.39, 185.10; ES-MS m/z (M+H);

Workup

  1. filtrationThe mixture was filtered through Celite© (175 g)
  2. washthe cake was washed with CH2Cl2
  3. customThe solvent was removed from the eluent under reduced pressure
  4. customthe resultant residue purified by column chromatography on silica gel (3% MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-f29db05be7d443a3a9ee7ebdc55000ce
Source dataset
uspto-grants-2014_07
Patent number
US08778967B2

Reaction notes

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