Hydrogen Bromide → 5-Bromo-2-(carboxymethyl)benzoic acid

HRID 1680498ノート

反応式

HRID 1680498 の反応式
[C:1]([C:4]1[CH:9]=[C:8]([N+]([O-])=O)[CH:7]=[CH:6][C:5]=1[CH2:13][C:14]([OH:16])=[O:15])([OH:3])=[O:2].N([O-])=O.[Na+].[BrH:21]>[Pd].O>[Br:21][C:8]1[CH:7]=[CH:6][C:5]([CH2:13][C:14]([OH:16])=[O:15])=[C:4]([C:1]([OH:3])=[O:2])[CH:9]=1

参加物

6

反応物 3

HCID 260Hydrogen BromideHCID 123034522-(Carboxymethyl)-5-nitrobenzoic acidHCID 23668193Sodium Nitrite

生成物 1

HCID 106349875-Bromo-2-(carboxymethyl)benzoic acid

試薬・触媒・溶媒 2

HCID 23938Palladium触媒HCID 962Water溶媒2 回

実験手順

A mixture of 2-carboxy-4-nitrophenylacetic acid (described by H. E. Ungnade et al., J. Org. Chem., 10, 533 (1945), 50 g, 0.22 mol) and 5% palladium on carbon (5 g) is rapidly stirred under an atmosphere of hydrogen until the nitro group is reduced. Water (300 ml) is added and the mixture is warmed to dissolve the precipitate. The mixture is filtered through diatomaceous earth. The filtrate is evaporated and 375 ml of 2 N hydrobromic acid is added. The resulting solution is cooled in an ice-bath to 0°-5° C. Sodium nitrite (15.2 g, 0.22 mol) in 50 ml of water is added while stirring. The latter solution is added slowly to a cold (0°-5° C.) stirring freshly prepared solution of cuprous bromide (150 g, 0.105 mol) in 230 ml of 49% hydrobromic acid. The reaction is stirred at room temperature for 2 hr and the precipitate is collected by filtration. The precipitate is washed with water and dried to obtain 4-bromo-2-carboxyphenylacetic acid (53 g), mp 210°-213° C.

後処理

  1. temperaturethe mixture is warmed
  2. dissolutionto dissolve the precipitate
  3. filtrationThe mixture is filtered through diatomaceous earth
  4. customThe filtrate is evaporated
  5. addition375 ml of 2 N hydrobromic acid is added
  6. temperatureThe resulting solution is cooled in an ice-bath to 0°-5° C
  7. stirringwhile stirring
  8. additionThe latter solution is added slowly to a cold (0°-5° C.)
  9. stirringThe reaction is stirred at room temperature for 2 hr
  10. filtrationthe precipitate is collected by filtration
  11. washThe precipitate is washed with water
  12. customdried

出典と根拠

ORDレコード
ord-9b53afa92c084fa0b27f4555cbad11f3
出典データセット
uspto-grants-1981_06
特許番号
US04273773

反応ノート

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