Potassium Iodide → 1-(2,4-Dichlorobenzyl)-4-ethoxycarbonyl-2-methylbenzimidazole

HRID 1699634Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[C:14]2[NH:13][C:12]([CH3:15])=[N:11][C:10]=2[CH:9]=[CH:8][CH:7]=1)=[O:5])[CH3:2].[Cl:16][C:17]1[CH:24]=[C:23]([Cl:25])[CH:22]=[CH:21][C:18]=1[CH2:19]Cl.[I-].[K+].C(=O)([O-])[O-].[K+].[K+]>O.C(Cl)(Cl)Cl.CN(C)C=O>[Cl:16][C:17]1[CH:24]=[C:23]([Cl:25])[CH:22]=[CH:21][C:18]=1[CH2:19][N:11]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[C:14]=2[N:13]=[C:12]1[CH3:15]

Participants

Conditions

Temperature: 80 °C

Procedure

A mixture of 4-ethoxycarbonyl-2-methylbenzimidazole (1.61 g), 2,4-dichlorobenzyl chloride (3.08 g), potassium iodide (1.51 g), potassium carbonate (1.05 g) and N,N-dimethylformamide (4 ml) is stirred for 16 hours at 80° C. Chloroform and water are added and extraction is performed. The chloroform layer is washed with water, dried, and concentrated. The residue is purified using silica gel column chromatography (eluate: hexane/ethyl acetate=2/8) and thus, 1-(2,4-dichlorobenzyl)-4-ethoxycarbonyl-2-methylbenzimidazole (0.730 g) is obtained. 1H-NMR (CDCl3, δ): 1.47 (3H, t, J=7.1 Hz), 2.63 (3H, s), 4.52 (2H, q, J=7.1 Hz), 5.39 (2H, s), 6.30 (1H, d, J=7.06 (1H, dd, J=2.1 and 8.4 Hz), 7.25 (1H, t, J=7.9 Hz), 7.32 (1H, dd, J=1.0 and 7.9 Hz), 7.48 (1H, d, J=2.0 Hz), 7.93 (1H, dd, J=1.0 and 7.7 Hz).

Workup

extractionextraction
washThe chloroform layer is washed with water
customdried
concentrationconcentrated
customThe residue is purified

Sources & evidence

ORD record: ord-46deed2186c94324bfd7cab6406f7d65
Source dataset: uspto-grants-2002_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06348032B1

Reaction notes

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