Hydrogen Bromide → 5-Bromo-7-fluoro-2,3-dihydrobenzo[b][1,4]dioxine

HRID 1054446노트

반응식

HRID 1054446 반응식
N([O-])=O.[Na+].[F:5][C:6]1[CH:7]=[C:8](N)[C:9]2[O:14][CH2:13][CH2:12][O:11][C:10]=2[CH:15]=1.[BrH:17]>O>[Br:17][C:8]1[C:9]2[O:14][CH2:13][CH2:12][O:11][C:10]=2[CH:15]=[C:6]([F:5])[CH:7]=1

참가 물질

5

실험 절차

NaNO2 (2.69 g, 39.9 mmol) in water (20 mL) was added slowly at 0° C. to a solution of 7-fluoro-2,3-dihydrobenzo[b][1,4]dioxin-5-amine (4.5 g, 26 mmol) in aq. 47% HBr (20 mL) and continued stirring at same temperature for 30 min. The above diazonium salt solution was added slowly to a solution of CuBr (5.7 g, 39.9 mmol) in aq. 47% HBr (25 mL) at 0° C. and stirred at 25° C. for 30 min. Reaction mixture was quenched with ice water, extracted with ethyl acetate (3×50 mL), washed it with water followed by brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude. The crude was purified by column purification (using silica gel and 0-5% ethyl acetate in Hexane as eluent) to afford 5-bromo-7-fluoro-2,3-dihydrobenzo[b][1,4]dioxine (Int-28) (5.9 g). 1H NMR (300 MHz, CDCl3) δ 6.9-6.84 (1H, dd), 6.6-6.5 (1H, dd), 4.3-4.3 (4H, m) ppm.

후처리

  1. stirringstirred at 25° C. for 30 min
  2. customReaction mixture
  3. customwas quenched with ice water
  4. extractionextracted with ethyl acetate (3×50 mL)
  5. washwashed it with water
  6. dry with materialdried over anhydrous sodium sulphate
  7. concentrationconcentrated under reduced pressure
  8. customto afford crude
  9. customThe crude was purified by column purification (using silica gel and 0-5% ethyl acetate in Hexane as eluent)

출처 및 근거

ORD 기록
ord-cdfa4b24b41041958c6c4102f335dc2f
출처 데이터셋
uspto-grants-2016_07
특허 번호
US09394305B2

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