1,2-Cyclohexanedione → 4-Oxo-4,5,6,7-tetrahydro-1-benzofuran-3-carboxylic acid

HRID 375403

Reaction equation

[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+]>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

Participants

Conditions

Temperature: 0 °C

Procedure

4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid was prepared according to a modified literature procedure 1. To a stirring solution of potassium hydroxide (28.06 g, 0.5 mol) in methanol (100 mL) under Nitrogen at 0° C. was added dropwise a solution of cyclohexanedione (56.07 g, 0.5 mol) in methanol (100 mL). The mixture was stirred at 0° C. for 0.5 h, then a solution of ethyl bromopyruvate (66 mL, 0.525 mol) in methanol (100 mL) was added dropwise. After allowing the mixture to stir at ambient temperature for 17 h, a 50% aqueous sodium hydroxide solution (60 mL) was added dropwise and stirring continued an additional 7 h. After dilution with water, the solution was acididfied and the methanol removed in vacuo. Ice water was added and the precipitate filtered and dried in vacuo to afford 4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid.

Workup

custom4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid was prepared
stirringto stir at ambient temperature for 17 h
stirringstirring
waitcontinued an additional 7 h
customthe methanol removed in vacuo
additionIce water was added
filtrationthe precipitate filtered
customdried in vacuo

Sources & evidence

ORD record: ord-4cfa5899c26a44fe8535effb3e52de56
Source dataset: uspto-grants-1996_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05484944

Linked notes

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