反应详情

温度

175 °C

To a solution of ethyl 6-bromo-1-ethyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate (Intermediate 15, 470 mg, 1.44 mmol) dissolved in ethanol (30 mL) was added 10% potassium hydroxide (2.9 mL, 2.89 mmol) and the mixture was heated to 175° C. for 1 h. The solvent was evaporated under reduced pressure to a residue. Water (20 mL) was added to the residue and the pH was adjusted to 3 with dilute hydrochloric acid (2N) to give solid precipitate which was filtered and dried to afford 340 mg (80%) of 6-bromo-1-ethyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid.

1. customThe solvent was evaporated under reduced pressure to a residue
2. additionWater (20 mL) was added to the residue
3. customto give solid precipitate which
4. filtrationwas filtered
5. customdried