Triethylamine → methyl 4-chloro-2-[(2,4-dichloro-6-methylphenyl)amino]-1-(3-hydroxypropyl)-1H-benzimidazole-7-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 4-chloro-3-{[(2,4-dichloro-6-methylphenyl)carbamothioyl]amino}-2-[(3-hydroxypropyl)amino]benzoate (Reference example 118, 2.17 g, 4.55 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (872 mg, 4.55 mmol) and triethylamine (0.70 mL) in tetrahydrofuran (20 mL) was stirred at 50° C. for 12 hr. The mixture was diluted with saturated aqueous sodium hydrogen carbonate, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 10-60% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give methyl 4-chloro-2-[(2,4-dichloro-6-methylphenyl)amino]-1-(3-hydroxypropyl)-1H-benzimidazole-7-carboxylate as a brown wax (1.67 g).

Provenance & Evidence