Ethylene Glycol → 5-(1,3-Dioxolan-2-YL)-2-fluoropyridine

HRID 1811820

反応式

HRID 1811820 の反応式
[F:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[CH:4][N:3]=1.[CH2:10](O)[CH2:11][OH:12].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1.C(=O)(O)[O-].[Na+].O.CCOC(C)=O>[O:7]1[CH2:10][CH2:11][O:12][CH:6]1[C:5]1[CH:8]=[CH:9][C:2]([F:1])=[N:3][CH:4]=1

参加物

8

反応物 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 164142462-Fluoro-5-formylpyridine

生成物 1

HCID 601557925-(1,3-Dioxolan-2-YL)-2-fluoropyridine収率 94%

試薬・触媒・溶媒 4

HCID 962Water溶媒HCID 1140Toluene溶媒HCID 8857Ethyl Acetate溶媒HCID 516892Sodium Bicarbonate溶媒

反応条件

温度
120 °C

実験手順

6-Fluoronicotinaldehyde (Asymchem Laboratories, Inc., Morrisville, N.C., 3.035 g, 24.26 mmol) was suspended in toluene (80 mL) and ethylene glycol (1.40 mL, 25.1 mmol) and p-toluenesulfonic acid (Acros Organics, Geel, Belgium, 12% in acetic acid, 0.15 mL) was added. The flask was fitted with a reflux condenser and placed in a preheated oil bath (120° C.) and stirred under nitrogen for 20 minutes. At this time, the reflux condenser was replaced with a Dean-Stark trap, and stirring was continued at 120° C. for 25 minutes. Then, the reaction was cooled and diluted with saturated sodium bicarbonate solution (20 mL) (before it had cooled to room temperature). The reaction was then diluted with water (20 mL) and EtOAc (30 mL). The layers were separated, and the aqueous phase was extracted with EtOAc. The organic extracts were combined, dried over sodium sulfate, filtered, concentrated, and purified on a silica gel filter (about 3 inches, 40:1 DCM/MeOH to 30:1 DCM/MeOH) to afford 5-(1,3-dioxolan-2-yl)-2-fluoropyridine (3.858 g), which was taken on to the next step. MS (ESI pos. ion) m/z 170 (M+H)+.

後処理

  1. customThe flask was fitted with a reflux condenser
  2. customplaced in a preheated oil bath
  3. stirringstirring
  4. waitwas continued at 120° C. for 25 minutes
  5. temperatureThen, the reaction was cooled
  6. customThe layers were separated
  7. extractionthe aqueous phase was extracted with EtOAc
  8. dry with materialdried over sodium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated
  11. custompurified on a silica gel
  12. filtrationfilter (about 3 inches, 40:1 DCM/MeOH to 30:1 DCM/MeOH)

出典と根拠

ORDレコード
ord-a3c9c18067484cc596e5df2ac0185fe6
出典データセット
uspto-grants-2013_01
特許番号
US08362241B2

関連ノート

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