O-Xylene → 4-Bromo-4-chloroaniline

Participants

Reaction Conditions

Reaction Steps

A mixture of isopropyl [2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]acetate (Reference Example 10; 1.33 g, 3.72 mmol), 4-bromo-2-chloroaniline (1.92 g, 9.31 mmol), p-toluenesulfonic acid monohydrate (707.6 mg, 3.98 mmol) and xylene (10.0 mL) was stirred at 150° C. for 2 hr. After cooling, the reaction mixture was diluted with water and extracted with ethyl acetate (×3). The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 0-15% ethyl acetate/n-hexane gradient mixture to give isopropyl {2-[(4-bromo-2-chlorophenyl)amino-4-chloro]-7-(1-ethylpropyl)-1H-benzimidazol-1-yl}acetate and 4-bromo-4-chloroaniline. The mixture was used for the next step without further purification.

Provenance & Evidence