Phosphorus oxychloride → 3,5-Dichloro-2-ethylquinoxaline

HRID 75372ノート

反応式

HRID 75372 の反応式
[Cl:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:11]=1[NH:10][C:9](=O)[C:8]([CH2:13][CH3:14])=[N:7]2.O=P(Cl)(Cl)[Cl:17]>>[Cl:17][C:9]1[C:8]([CH2:13][CH3:14])=[N:7][C:6]2[C:11]([N:10]=1)=[C:2]([Cl:1])[CH:3]=[CH:4][CH:5]=2

参加物

3

反応物 2

HCID 24813Phosphorus oxychlorideHCID 866985098-chloro-3-ethylquinoxalin-2(1H)-one

生成物 1

HCID 866985103,5-Dichloro-2-ethylquinoxaline収率 77.2%

実験手順

A thick slurry of 8-chloro-3-ethylquinoxalin-2(1H)-one (1.00 Kg, 4.79 mol) in POCl3 (2.68 L, 28.8 mol) was stirred at 100° C. for 2 h. At this time LC-MS analysis showed that the reaction was complete. After the removal of most of the POCl3 under reduced pressure, the residue was poured carefully into ice-water and neutralized with a combination of 2M aq. NaOH and saturated aq. NaHCO3. The resulting suspension was extracted with DCM (3×4 L). The organic phase was washed with brine, dried over anhydrous Na2SO4, filtered, and evaporated under reduced pressure. The crude was purified by flash column chromatography eluting with hexane/EtOAc (30/1) to give 3,5-dichloro-2-ethylquinoxaline (840 g) as a white solid. 1H NMR (DMSO-d6) δ ppm 8.01-8.08 (m, 2H), 7.84 (t, J=8.0 Hz, 1H), 3.10-3.17 (d, J=7.3 Hz, 2H), 1.36 (t, J=7.3 Hz, 3H). Mass Spectrum (ESI) m/z=227.1 (M+1).

後処理

  1. customAfter the removal of most of the POCl3 under reduced pressure
  2. additionthe residue was poured carefully into ice-water
  3. extractionThe resulting suspension was extracted with DCM (3×4 L)
  4. washThe organic phase was washed with brine
  5. dry with materialdried over anhydrous Na2SO4
  6. filtrationfiltered
  7. customevaporated under reduced pressure
  8. customThe crude was purified by flash column chromatography
  9. washeluting with hexane/EtOAc (30/1)

出典と根拠

ORDレコード
ord-a70d8cb72b914c408c956c122fe403d9
出典データセット
uspto-grants-2014_09
特許番号
US08835432B2

反応ノート

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