반응 #1532719
ord-7a16e7b31bad44ecb2154a18c0c8c7c6
반응 방정식
반응물
시약
반응 조건
후처리
- 1기타The reaction mixture thinned to form a pale green, nearly clear solution
- 2기타to form a pale yellow suspension
- 3온도the reaction mixture was heated
- 4온도at gentle reflux for 3.5 hours
- 5온도After cooling
- 6기타a precipitate of white solid was removed by filtration
- 7추출Concentration of the acetonitrile mother liquor and then dilution with water (400 mL) was followed by extraction three times with ethyl ether (700 mL total)
- 8농축The ethyl ether phase was concentrated to a reduced volume (75 mL) from which
- 9기타precipitated an-off white solid (3.75 g), which
- 10여과was collected by filtration
- 11농축The ether mother liquor was further concentrated
실험 절차
To a suspension of ethyl 1-(3-chloro-2-pyridinyl)-3-pyrazolidinone-5-carboxylate (i.e. the product of 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. Concentration of the acetonitrile mother liquor and then dilution with water (400 mL) was followed by extraction three times with ethyl ether (700 mL total). The ethyl ether phase was concentrated to a reduced volume (75 mL) from which precipitated 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 collected by filtration. Further precipitation of an off-white solid (4.5 g) from the aqueous phase yielded a combined total of 12.45 g of the title compound.