Phosphorus oxychloride → 2-Chloro-4-methoxypyridine

HRID 2251748ノート

反応式

HRID 2251748 の反応式
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][NH:6][C:5](=O)[CH:4]=1.O=P(Cl)(Cl)[Cl:12]>>[Cl:12][C:5]1[CH:4]=[C:3]([O:2][CH3:1])[CH:8]=[CH:7][N:6]=1

参加物

3

反応物 2

HCID 24813Phosphorus oxychlorideHCID 8177154-Methoxypyridin-2(1H)-one

生成物 1

HCID 19911282-Chloro-4-methoxypyridine収率 63%

実験手順

4-Methoxy-2-pyridone (10) (0.805 g, 6.43 mmol) and freshly distilled POCl3 (8 mL) were heated at reflux for 15 h. Excess POCl3 was removed in vacuo and the resultant viscous oil was cooled in ice and carefully neutralised with saturated NaHCO3 solution. The mixture was extracted with EtOAc (×3) and the extracts were worked up in the standard manner to give a brown oil. This material was partially purified by vacuum distillation in a Kugelrohr apparatus (100° C., 0.07 mm Hg). The distillate was triturated with petroleum ether and a white precipitate was filtered off. The filtrate was concentrated and final purification by flash chromatography on silica gel using 30% EtOAc/hexanes as the eluant gave 2-chloro-4-methoxypyridine (11) as a colourless oil (0.586 g, 63%).

後処理

  1. temperatureat reflux for 15 h
  2. customExcess POCl3 was removed in vacuo
  3. temperaturethe resultant viscous oil was cooled in ice
  4. extractionThe mixture was extracted with EtOAc (×3)
  5. customto give a brown oil
  6. distillationThis material was partially purified by vacuum distillation in a Kugelrohr apparatus (100° C., 0.07 mm Hg)
  7. distillationThe distillate was triturated with petroleum ether
  8. filtrationa white precipitate was filtered off
  9. concentrationThe filtrate was concentrated
  10. customfinal purification by flash chromatography on silica gel using 30% EtOAc/hexanes as the eluant

出典と根拠

ORDレコード
ord-8863f36082f744609816e1fc81ebd4a5
出典データセット
uspto-grants-2008_01
特許番号
US07320981B2

反応ノート

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