Dimethylformamide → HCID 18681168, compound

Participants

Reaction Conditions

Reaction Steps

N,N-dimethylformamide (15 ml), 2-nitrobenzyl bromide (1.59 g) and sodium bicarbonate (1.23 g) are added to 5-ethoxycarbonyl-2-methylbenzimidazole (1.00 g) and the solution is heated for one hour at 60° C. After adding ethyl acetate (70 ml) and water (70 ml) and separating the solution, the organic layer is washed with water three times and extraction is performed on the aqueous layer using ethyl acetate three times. By concentrating the obtained organic layer under reduced pressure, a mixture of 6-ethoxycarbonyl-2-methyl-1-(2-nitrobenzyl)benzimidazole and 5-ethoxycarbonyl-2-methyl-1-(2-nitrobenzyl)benzimidazole is obtained. Purification using medium pressure silica gel column chromatography (eluate: hexane/etlhyl acetate=1/4˜0/100) produced 6-ethoxycarbonyl-2-methyl-1-(2-nitrobenzyl)benzimidazole (83) (0.614 g) and 5-ethoxycarbonyl-2-methyl-1-(2-nitrobenzyl)benzimidazole (84) (0.259 g). 1H-NMR CDCl3, δ): 1.38 (3H, t, J=7.2 Hz), 2.56 (3H, s), 4.37 (2H, q, J=7.1 Hz), 5.84 (2H, s), 6.41 (1H, d, J=6.8 Hz), 7.44-7.53 (2H, m), 7.78 (1H, d, J=8.6 Hz), 7.88 (1H, s), 8.02 (1H, dd, J=8.3 and 1.5 Hz), 8.30 (1H, dd, J=7.9 and 1.5 Hz).

Provenance & Evidence