反应详情

A suspension of ethyl 1-(3-bromophenyl)-1,4-dihydro[1,8]naphthyridin-4-one-3-carboxylate from Step 2 (52.5 g, 140.7 mmol) in a mixture of tetrahydrofuran (400 mL), methanol (400 mL) and 1N aqueous sodium hydroxide (280 mL) was heated at ca 50° C. with stirring for 20 minutes. After cooling, the mixture was diluted with water (300 mL) and 1N aqueous HCl (325 mL) was added. After stirring for 45 minutes, the precipitate was filtered, washed well with water and dried to afford the 1-(3-bromophenyl)-1,4-dihydro[1,8]naphthyridin-4-one-3-carboxylic acid as a cream-colored solid.

1. temperaturewas heated at ca 50° C.
2. temperatureAfter cooling
3. additionwas added
4. stirringAfter stirring for 45 minutes
5. filtrationthe precipitate was filtered
6. washwashed well with water
7. customdried