反応 #792174
ord-6e206051077f4a788d0f3e7729061cd6
反応方程式
反応物
試薬
反応条件
後処理
- 1その他The reaction mixture thinned to form a pale green, nearly clear solution
- 2その他to form a pale yellow suspension
- 3温度the reaction mixture was heated
- 4温度at gentle reflux for 3.5 hours
- 5温度After cooling
- 6その他a precipitate of white solid was removed by filtration
- 7workup.ADDITIONThe filtrate was diluted with water (400 mL)
- 8抽出extracted three times with ethyl ether (700 mL total)
- 9その他precipitation of an off-white solid (3.75 g), which
- 10ろ過was collected by filtration
- 11濃縮The ether mother liquor was further concentrated
実験手順
To a suspension of ethyl 2-(3-chloro-2-pyridinyl)-5-oxo-3-pyrazolidinecarboxylate (i.e. product of Example 12, Step A) (27 g, 100 mmol) stirred in dry acetonitrile (200 mL) was added sulfuric acid (20 g, 200 mmol) in one portion. The reaction mixture thinned to form a pale green, nearly clear solution before thickening again to form a pale yellow suspension. Potassium persulfate (33 g, 120 mmol) was added in one portion, and then the reaction mixture was heated at gentle reflux for 3.5 hours. After cooling using an ice bath, a precipitate of white solid was removed by filtration and discarded. The filtrate was diluted with water (400 mL) and then extracted three times with ethyl ether (700 mL total). Concentration of the combined ether extracts to a reduced volume (75 mL) caused precipitation of an off-white solid (3.75 g), which was collected by filtration. The ether mother liquor was further concentrated to yield a second crop of an off-white precipitate (4.2 g), which was also collected by filtration. An off-white solid also precipitated from the aqueous phase; this solid (4.5 g) was collected by filtration to provide a combined total of 12.45 g of the title compound.