Diisopropylethylamine → 2-Pyridyl-pyrrolidin-1-yl-benzoxazole

Participants

Reaction Steps

The crude pyrrolidine (5.9 g, 0.025M) was dissolved in 100 mL 1,4-dioxane containing N,N-diisopropylethylamine (435 mL, 0.025M). Then 2,5-dichlorobenzoxazole (4.7 g, 0.025M) was added and the resulting yellow solution was heated at reflux for 2 hours, cooled to room temperature and diluted with 250 mL ethyl acetate. The reaction mixture was washed with 200 mL portions of water and saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated to obtain a yellow oil. Chromatography on silica gel with methylene chloride-methanol resulted in 4.6 g (47%) of the desired cis-+/--5-chloro-3-(4-fluorophenyl)-2-(2-pyridyl-pyrrolidin- 1-yl-benzoxazole, mp 149°-150° C.

Provenance & Evidence