Sulfuric Acid → 5-Bromo-2-chloro-4-ethoxypyridine

HRID 1050106ノート

反応式

HRID 1050106 の反応式
[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH2:9][CH3:10])[CH:5]=[CH:4][N:3]=1.OS(O)(=O)=O.C1C(=O)N([Br:23])C(=O)C1>O>[Br:23][C:5]1[C:6]([O:8][CH2:9][CH3:10])=[CH:7][C:2]([Cl:1])=[N:3][CH:4]=1

参加物

5

反応物 3

HCID 1118Sulfuric AcidHCID 67184N-bromobutanimideHCID 8172382-Chloro-4-ethoxypyridine

生成物 1

HCID 707008775-Bromo-2-chloro-4-ethoxypyridine収率 32.1%

試薬・触媒・溶媒 1

HCID 962Water溶媒

反応条件

温度
60 °C

実験手順

To a mixture of 2-chloro-4-ethoxypyridine (13 g, 82 mmol) and H2SO4 (40 mL, 750 mmol) was added NBS (17.62 g, 99 mmol). Then the mixture was stirred at 60° C. for 10 h. After cooling to rt, the mixture was poured into cold water (300 mL). The mixture was extracted with EA (200 mL×2). The combined organic layer was washed with saturated NaHCO3 solution (200 mL×2) and concentrated. The crude material was purified by silica column chromatography (PE/EA=15:1). All fractions found to contain product by TLC (PE/EA=5:1, Rf=0.6) were combined and concentrated to yield a yellow solid of 5-bromo-2-chloro-4-ethoxypyridine (8.5 g, 26.3 mmol, 32% yield): 1H NMR (400 MHz, CDCl3) δ 8.32 (s, 1H), 6.79 (s, 1H), 4.16 (q, J=6.8 Hz, 2H), 1.50 (t, J=6.8 Hz, 3H); ES-LCMS m/z 238 (M+3).

後処理

  1. temperatureAfter cooling to rt
  2. extractionThe mixture was extracted with EA (200 mL×2)
  3. washThe combined organic layer was washed with saturated NaHCO3 solution (200 mL×2)
  4. concentrationconcentrated
  5. customThe crude material was purified by silica column chromatography (PE/EA=15:1)
  6. concentrationconcentrated

出典と根拠

ORDレコード
ord-47141a4a5c8f4aa4a7d666ea356e6b1d
出典データセット
uspto-grants-2016_07
特許番号
US09382238B2

反応ノート

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