Cesium carbonate → 7-chloro-6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-3-methyl-1,2-benzoxazole-5-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 3-chloro-2-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-4-fluoro-5-[N-hydroxyethanimidoyl]benzoate (Intermediate 171, 700 mg, 1.94 mmol) in DMF (4 mL) was added Cs2CO3 (1.9 g, 5.84 mmol) and the mixture was heated to 130° C. for 14 hours. The reaction mixture was cooled to room temperature and filtered through a celite bed. The solvent was removed under vacuum and the residue was purified by silica gel chromatography column using ethyl acetate-pet. ether gradient to obtain product. Yield: 250 mg, (41%).

Provenance & Evidence