Methyl iodide → HCID 22663244, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of sodium hydride (0.55 g, 60% dispersion in mineral oil) in dimethylformamide (1 ml), cooled to 0° C., was treated with a solution of methyl 2-cyclopentyl-7-methoxy-3H-benzimidazole-4-carboxylate [3.61 g, Reference Example 3(t)]) in dimethylformamide (34 ml). The resulting mixture was stirred for 40 minutes then treated with iodomethane (0.82 ml). The reaction mixture was allowed to stand at 4° C. for 2 days then diluted with diethyl ether, then washed with brine, then dried over magnesium sulphate and then evaporated. The residue was subjected to flash chromatography on silica to give methyl 2-cyclopentyl-7-methoxy-1-methyl-1H-benzimidazole-4-carboxylate (3.18 g), [NMR (CDCl3): δ 1.70 (m,2H), 1.90(m,2H), 2.16(m,4H), 3.25(m,1H), 3.95(s,6H), 4.00(s,3H), 6.64(d,J=8 Hz,1H), 7.89(d,J=8 Hz,1H)]; and methyl 2-(cyclopentyl)-7-methoxy-3-methyl-3H-benzimidazole-4-carboxylate (0.37 g), [M+288, NMR (CDCl3): δ 1.70(m,2H), 1.90(m,2H), 2.14(m,4H), 3.25(m,1H), 3.92(s,6H), 4.02(s,3H), 6.64(d,J=8 Hz,1H), 7.75(d,J=8 Hz,1H)].

Provenance & Evidence