Phosphorus oxychloride → 2-Chloro-6-fluoroquinoxaline

HRID 1852285ノート

反応式

HRID 1852285 の反応式
[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7](=O)[CH:6]=[N:5]2.[F:13][C:14]1[CH:23]=[C:22]2[C:17]([N:18]=[CH:19][C:20](=O)[NH:21]2)=[CH:16][CH:15]=1.O=P(Cl)(Cl)[Cl:27]>>[Cl:27][C:7]1[CH:6]=[N:5][C:4]2[C:9](=[CH:10][CH:11]=[C:2]([F:1])[CH:3]=2)[N:8]=1.[Cl:27][C:20]1[CH:19]=[N:18][C:17]2[C:22](=[CH:23][C:14]([F:13])=[CH:15][CH:16]=2)[N:21]=1

参加物

5

反応物 3

HCID 24813Phosphorus oxychlorideHCID 126863866-Fluoro-1,2-dihydroquinoxalin-2-oneHCID 217275347-fluoroquinoxalin-2(1H)-one

生成物 2

HCID 126864072-Chloro-6-fluoroquinoxaline収率 44%HCID 714639612-Chloro-7-fluoroquinoxaline収率 38%

実験手順

A solution of 6-fluoroquinoxalin-2(1H)-one & 7-fluoroquinoxalin-2(1H)-one (3 g, 18.28 mmol) in POCl3 (20 ml) was refluxed for 3 h. The solvent was evaporated under reduced pressure and the residue was diluted with cold water. The aqueous solution was basified by solid sodium carbonate and extracted with ethyl acetate. The combine organic layer was dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure to get crude compound. The crude compound was purified by silica gel chromatography (20% ethyl acetate in pet ether) to afford regioisomers as a mixture. The above mixture was separated by SFC purification to afford 2-chloro-6-fluoroquinoxaline (0.75 g, 44%) and 2-chloro-7-fluoroquinoxaline (0.65 g, 38%) as white solid.

後処理

  1. customThe solvent was evaporated under reduced pressure
  2. additionthe residue was diluted with cold water
  3. extractionextracted with ethyl acetate
  4. dry with materialThe combine organic layer was dried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. customevaporated under reduced pressure
  7. customto get crude compound
  8. customThe crude compound was purified by silica gel chromatography (20% ethyl acetate in pet ether)
  9. customto afford regioisomers as a mixture
  10. customThe above mixture was separated by SFC purification

出典と根拠

ORDレコード
ord-4126f29d182e41c5b04d03d581f02992
出典データセット
uspto-grants-2015_02
特許番号
US08957203B2

反応ノート

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