Triethylamine → Ethyl 6-bromo-1-{2-[(methylsulfonyl)oxy]ethyl}-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate

Participants

Reaction Steps

A solution of ethyl 6-bromo-1-(2-hydroxyethyl)-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate (Intermediate 17, 800 mg, 2.34 mmol) and triethylamine (473 mg, 4.69 mmol) in dichloromethane (50 mL) was cooled to 0° C. and methane sulphonyl chloride (400 mg, 3.50 mmol) was added drop wise. The mixture was allowed to stir at room temperature for 3 h. The reaction mixture was washed with water and the organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford 700 mg, (71%) of ethyl 6-bromo-1-{2-[(methylsulfonyl)oxy]ethyl}-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate, which was taken without further purification to next step.

Provenance & Evidence