反应 #670010

ord-32971cf71d62453cab038f4741e3c23f

反应条件

温度
0°CELSIUS
详细条件
See reaction.notes.procedure_details.

后处理

  1. 1
    其他4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid was prepared
  2. 2
    workup.STIRRINGto stir at ambient temperature for 17 h
  3. 3
    workup.WAITsiring continued an additional 7 h
  4. 4
    其他the methanol removed in vacuo
  5. 5
    workup.ADDITIONIce water was added
  6. 6
    过滤the precipitate filtered
  7. 7
    其他dried in vacuo

实验过程

4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid was prepared as follows: To a stirred solution of potassium hydroxide (28.06 g, 0.5 mol) in methyl alcohol (100 mL) under nitrogen at 0° C. was added dropwise a solution of cyclohexanedione (56.07 g, 0.5 mol) in methyl alcohol (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 methyl alcohol(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 siring continued an additional 7 h. After dilution with water, the solution was acidified 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. m.p. 137-138° C.

来源

DOI: 10.6084/m9.figshare.5104873.v1专利: US05925770uspto-grants-1999_07