Sulfuric Acid → Ethyl 6-bromoimidazo[1,2-a]pyridine-3-carboxylate

HRID 1045408ノート

反応式

HRID 1045408 の反応式
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([NH2:8])=[N:6][CH:7]=1.[K].Cl[C:11](=[CH:17]O)[C:12]([O:14][CH2:15][CH3:16])=[O:13].S(=O)(=O)(O)O>CCO>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[CH:17][N:8]=2)[CH:7]=1

参加物

5

反応物 3

HCID 1118Sulfuric AcidHCID 706222-Amino-5-bromopyridineHCID 86677443Ethyl 2-chloro-3-hydroxyacrylate potassium salt

生成物 1

HCID 22031055Ethyl 6-bromoimidazo[1,2-a]pyridine-3-carboxylate

試薬・触媒・溶媒 1

HCID 702Ethanol溶媒

反応条件

温度
78 °C

実験手順

To a stirring suspension of 5-bromopyridin-2-amine (1.2 g, 7.05 mmol) and ethyl 2-chloro-3-hydroxyacrylate potassium salt (6.6 g, 28.19 mmol) (prepared in a similar manner as 22) in EtOH (100 mL) at room temperature was added sulfuric acid (751 μL, 14.10 mmol) dropwise. The reaction mixture was heated at 78° C. overnight. The reaction was cooled to room temperature and the solvent was concentrated. The residue was taken in water and the pH was adjusted between 6-8 with saturated sodium bicarbonate. The crude product was extracted with ethyl acetate. The organic was washed with brine and dried over anhydrous sodium sulfate. The crude product was purified by silica chromatography to yield ethyl 6-bromoimidazo[1,2-a]pyridine-3-carboxylate (24s). MS m/z 270.2 (M+1)+.

後処理

  1. temperatureThe reaction was cooled to room temperature
  2. concentrationthe solvent was concentrated
  3. extractionThe crude product was extracted with ethyl acetate
  4. washThe organic was washed with brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. customThe crude product was purified by silica chromatography

出典と根拠

ORDレコード
ord-85b1635426cf432a93361adf2b5213e2
出典データセット
uspto-grants-2013_10
特許番号
US08569283B2

反応ノート

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