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

HRID 747374

Reaction equation

HRID 747374 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][CH:2]=1.C(N(CC)C(C)C)(C)C.[CH3:19][Si:20]([CH3:27])([CH3:26])[CH2:21][CH2:22][O:23][CH2:24]Cl.CN([CH:31]=[O:32])C>>[CH3:19][Si:20]([CH3:27])([CH3:26])[CH2:21][CH2:22][O:23][CH2:24][N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[C:2]1[CH:31]=[O:32]

Participants

5

Reactant 4

HCID 5798BenzimidazoleHCID 6228DimethylformamideHCID 81531DiisopropylethylamineHCID 27242712-Chloromethyl 2-(trimethylsilyl)ethyl ether

Product 1

HCID 120171281-(2-Trimethylsilylethoxymethyl)-2-formyl-benzimidazoleYield 76%

Procedure

To a stirred solution of benzimidazole (2.00 g, 16.9 mmol) in anhydrous DMF (25 mL) was added N,N-diisopropylethylamine (7.3 mL, 42.2 mmol) followed by 2-(trimethylsilyl)ethoxymethyl chloride (3.3 mL, 18.6 mmol) and the resultant solution was heated to 80 □C for 4 hours. Purification of the crude brown oil through a plug of silica gel (CH2Cl2/MeOH, 19:1) provided the 1-(2-trimethylsilylethoxymethyl)-benzimidazole (3.19 g, 76%) as an orange oil. 1H NMR (CDCl3) −0.05 (s, 9H), 0.90 (t, 2H, J=9 Hz), 3.51 (t, 2H, J=9 Hz), 5.55 (s, 2H), 7.32-7.37 (m, 2H), 7.55 (br d, 1H, J=6 Hz), 7.83 (br d, 1H, J=6 Hz), 7.98 (s, 1H).

Workup

  1. customPurification of the crude brown oil through a plug of silica gel (CH2Cl2/MeOH, 19:1)

Sources & evidence

ORD record
ord-3c5501a70bf84039b42eed984cea7248
Source dataset
uspto-grants-2008_07
Patent number
US07396840B2

Linked notes

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