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

Participants

Reaction Conditions

Reaction Steps

A solution of methyl 3-amino-4-chloro-2-[(2-hydroxyethyl)amino]benzoate (290 mg, 1.19 mmol) and 2,4-dichloro-6-methylphenylisothiocyanate (284.4 mg, 1.3 mmol) in tetrahydrofuran (12 mL) was stirred at 45° C. for 62 hr. The mixture was warmed to 60° C. and stirred at, 60° C. for 24 hr. 2,4-Dichloro-6-methylphenylisothiocyanate (104 mg, 0.48 mmol) was added to the reaction mixture and the mixture was stirred at 60° C. for 26 hr. Water was added to the reaction mixture at room temperature and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on NH-silica gel eluting with a 50-100% ethyl acetate/n-hexane gradient mixture give a red amorphous (261.4 mg). To a mixture of the amorphous (261.4 mg) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (119 mg, 0.62 mmol) in tetrahydrofuran (11.2 mL) was added triethylamine (0.0866 mL, 0.62 mmol) at room temperature. The mixture was stirred at 50° C. for 16 hr. Water was added to the reaction mixture at room temperature and the mixture was extracted with ethyl acetate. The organic layer was washed with water and brine, dried over anhydrous magnesium sulfate and concentrated in vacuo to give the title compound (156.3 mg, 0.36 mmol, 30%) as a pale yellow solid.

Provenance & Evidence