Acetic Acid → (S)-tert-butyl 2-(5-(4-bromophenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate

Participants

Reaction Steps

To the solution of (S)-tert-butyl 2-(2-(4-bromophenyl)-2-oxoethylcarbamoyl)pyrrolidine-1-carboxylate (compound 18a, 5.0 g, 12.2 mmol) in xylene (75 ml) were added ammonium acetate (23.4 g, 304 mmol) and acetic acid (5 ml) at room temperature. The reaction mixture was placed in an oil bath and heated to 160° C. with water being azeotroped into a Dean-Stark trap. After 3 hours, the resulting mixture was cooled to room temperature and then extracted with ethyl acetate and distillated water. The organic layer was dried over MgSO4, filtered, and concentrated under reduced pressure to give a crude product, which was purified with column chromatography (100% ethyl acetate) to yield the pure product 19a (4.4 g).

Provenance & Evidence