Hydrochloric Acid → 4-Oxo-4,5,6,7-tetrahydro-1-benzofuran-3-carboxylic acid

HRID 351897

反応式

HRID 351897 の反応式
[OH-:1].[K+].[C:3]1(=[O:10])[CH2:8][CH2:7][CH2:6][CH2:5][C:4]1=O.Br[CH2:12][C:13](=O)[C:14]([O:16]CC)=[O:15].[OH-].[Na+].Cl>CO.O>[O:10]=[C:3]1[C:4]2[C:13]([C:14]([OH:16])=[O:15])=[CH:12][O:1][C:5]=2[CH2:6][CH2:7][CH2:8]1

参加物

8

反応物 5

HCID 313Hydrochloric AcidHCID 130061,2-CyclohexanedioneHCID 14797Potassium Hydroxide2 回HCID 14798Sodium HydroxideHCID 66144Ethyl bromopyruvate

生成物 1

HCID 7139374-Oxo-4,5,6,7-tetrahydro-1-benzofuran-3-carboxylic acid収率 50.5%

試薬・触媒・溶媒 2

HCID 887Methanol溶媒3 回HCID 962Water溶媒

実験手順

4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid is prepared according to the following procedure. Potassium hydroxide (345 g, 6.15 mol) is dissolved in methyl alcohol (1.2 L) then cooled in an ice water bath. A solution of cyclohexanedione (714 g, 6.15 mol) in methyl alcohol (1.2 L), dissolved using gentle heat, is added dropwise to the cold, stirred KOH solution over 2 h. A solution of ethyl bromopyruvate (1200 g, 6.15 mol) in methyl alcohol (1.5 L) is then added dropwise over 3 h. The reaction mixture is allowed to reach ambient temperature and stirred an additional 14.5 h. While cooling the reaction mixture via a water bath, a solution of sodium hydroxide (492 g, 12.4 mol) in water (984 mL) is added dropwise over 2.5 h. After stirring at ambient temperature for 15.5 h, the reaction mixture is cooled in an ice water bath, 500 g of ice added, and the resulting mixture is then acidified with concentrated hydrochloric acid (ca 1 L) to pH 1. The reaction mixture is concentrated in vacuo, 1 L of ice is added, and the precipitate filtered, washed with ice water (3×200 mL), and then dried in a vacuum oven at 75° C. to afford 4-oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid (560 g). m.p. 137-138° C.

後処理

  1. custom4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid is prepared
  2. temperaturethen cooled in an ice water bath
  3. additionis added dropwise to the cold
  4. customto reach ambient temperature
  5. temperatureWhile cooling the reaction mixture via a water bath
  6. stirringAfter stirring at ambient temperature for 15.5 h
  7. temperaturethe reaction mixture is cooled in an ice water bath
  8. concentrationThe reaction mixture is concentrated in vacuo, 1 L of ice
  9. additionis added
  10. filtrationthe precipitate filtered
  11. washwashed with ice water (3×200 mL)
  12. customdried in a vacuum oven at 75° C.

出典と根拠

ORDレコード
ord-8b1832699e9048aabaedb08ce88b9862
出典データセット
uspto-grants-2004_06
特許番号
US06743817B2

関連ノート

読み込み中…