Diisopropylethylamine → Methyl(1RS,2SR)-2-(6-bromo-1-methyl-1H-benzimidazol-2-yl)cyclopropanecarboxylate

Participants

Reaction Steps

O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (554 mg) was added to a solution of 4-bromo-N2-methylbenzene-1,2-diamine (279 mg), diisopropylethylamine (0.727 mL) and (1RS,2SR)-2-(methoxycarbonyl)cyclopropanecarboxylic acid (200 mg) in DMF (5 mL) at room temperature. The mixture was stirred for 1 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with water and brine, dried over magnesium sulfate and concentrated in vacuo. The obtained residue was dissolved in acetic acid (5 mL), and the mixture was stirred at 80° C. for 1 hr. After concentration of the reaction mixture, saturated sodium hydrogen carbonate was added to the residue, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with water and brine, dried over magnesium sulfate and concentrated in vacuo. The obtained residue was purified by silica gel column chromatography (methanol/ethyl acetate) to give the title compound (80 mg) as a pale brown solid.

Provenance & Evidence