p-Toluenesulfonic acid → Ethyl 4-[4-chloro-2-[(4-chloro-2-methoxy-6-methylphenyl)amino]-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]butanoate

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Reaction Steps

A mixture of ethyl 4-[2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]butanoate (Reference Example 33; 470 mg, 1.27 mmol), 4-chloro-2-methoxy-6-methylaniline (650 mg, 3.81 mmol) and p-toluenesulfonic acid (241 mg, 1.27 mmol) and xylene (5.0 mL) was irradiated by microwave at 150° C. for 4 hr. After cooling, the reaction mixture was extracted with ethyl acetate (×3). The organics were dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 10-50% ethyl acetate/n-hexane gradient mixture to give the title compound (120 mg, 0.289 mmol, 18.7%) as a brown amorphous.

Provenance & Evidence