p-Toluenesulfonic acid monohydrate → Ethyl 4-{4-chloro-7-(1-ethylpropyl)-2-[(4-methyl-6-pyrrolidin-1-ylpyridin-3-yl)amino]-1H-benzimidazol-1-yl}butanoate

Participants

Reaction Steps

A mixture of ethyl 4-[2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]butanoate (Reference Example 33; 1.50 g, 4.04 mmol), 4-methyl-6-pyrrolidin-1-ylpyridin-3-amine (1.44 g, 8.09 mmol) and p-toluenesulfonic acid monohydrate (695 mg, 4.04 mmol) in 1-methyl-2-pyrrolidinone (8 mL) was irradiated by microwave at 180° C. for 110 min. After cooling, the mixture was diluted with ethyl acetate, washed with water and brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with a 20-100% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give a solid, which was recrystallized from ethyl acetate/isopropyl ether to give the title compound (745 mg, 1.46 mmol, 36%) as a colorless solid.

Provenance & Evidence