Hydrogen Bromide → 3-Bromo-5-(methoxycarbonyl)benzoic acid

HRID 42540

反応式

HRID 42540 の反応式
N[C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([C:11]([O:13][CH3:14])=[O:12])[CH:10]=1)[C:5]([OH:7])=[O:6].N([O-])=O.[Na+].[BrH:19]>>[Br:19][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([C:11]([O:13][CH3:14])=[O:12])[CH:10]=1)[C:5]([OH:7])=[O:6]

参加物

4

反応物 3

HCID 260Hydrogen Bromide2 回HCID 135576433-Amino-5-(methoxycarbonyl)benzoic acidHCID 23668193Sodium Nitrite

生成物 1

HCID 225936413-Bromo-5-(methoxycarbonyl)benzoic acid収率 68%

反応条件

温度
0 °C

実験手順

3-Amino-5-(methoxycarbonyl)benzoic acid (1.0 g, 5.12 mmol, 1 eq.) was dissolved in 15% HBr (22.5 mL) at RT, then cooled to 0° C. with stirring. A 2.5 M aqueous solution of NaNO2 (2.3 mL, 5.64 mmol, 1.1 eq.) was added slowly via an addition funnel to generate the diazonium salt. In a separate flask, CuBr was partially dissolved in 15% HBr (9 mL) and cooled to 0° C. with stirring, to which the diazonium salt solution was subsequently added. A slight exotherm was observed. The reaction was stirred at RT for 30 minutes then carefully heated at 70° C. for 1 hour. The reaction was worked up by filtering off insoluble material as crude product. The solids were dissolved in water/EtOAc and the layers separated. The aqueous layer was extracted again with EtOAc. The organic layers were combined, dried over sodium sulfate and concentrated to give an off-white solid. The product was purified over silica gel in 1:1 hexanes/EtOAc to 100% EtOAc to 4:1 methylene chloride/MeOH to yield 3-bromo-5-(methoxycarbonyl)benzoic acid (0.90 g, 3.47 mmol, 68% yield) as a white solid. MS found: (M−H)+=257/259.

後処理

  1. temperaturecooled to 0° C.
  2. additionwas subsequently added
  3. stirringThe reaction was stirred at RT for 30 minutes
  4. temperaturethen carefully heated at 70° C. for 1 hour
  5. filtrationby filtering off insoluble material as crude product
  6. dissolutionThe solids were dissolved in water/EtOAc
  7. customthe layers separated
  8. extractionThe aqueous layer was extracted again with EtOAc
  9. dry with materialdried over sodium sulfate
  10. concentrationconcentrated
  11. customto give an off-white solid
  12. customThe product was purified over silica gel in 1:1 hexanes/EtOAc to 100% EtOAc to 4:1 methylene chloride/MeOH

出典と根拠

ORDレコード
ord-3e613da65351428bb2c345652ac97ce7
出典データセット
uspto-grants-2013_09
特許番号
US08536198B2

関連ノート

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