反応 #1377270

ord-d6f64b5f3d4f4caa8d9151e61eda8e0e

反応条件

詳細条件
See reaction.notes.procedure_details.

後処理

  1. 1
    温度at reflux for 1 hour
  2. 2
    温度cooled in an ice bath
  3. 3
    その他the resulting precipitate was collected
  4. 4
    洗浄rinsed with water
  5. 5
    その他to dry

実験手順

A mixture of ethyl 4-oxo-5,6,7,8-tetrahydro-4H-cyclohepta[b]furan-3-carboxylate (3.48 g,15.7 mmol) and ammonium acetate (2.41 g, 31.3 mmol) in N,N-dimethylformamide (25 mL) was heated at 115° C. for 6 hours. The mixture was concentrated in vacuo, ice water was added, and extracted 2X with dichloromethane. The combined organic layers were washed with saturated aqueous sodium bicarbonate then brine, dried over sodium sulfate, filtered through a small pad of Silica gel (5% methyl alcohol/dichloromethane), and the filtrate concentrated in vacuo to give ethyl 4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxylate (1.76 g). A solution of this ester in aqueous 5N sodium hydroxide (30 mL) and ethyl alcohol(6 mL) was heated at reflux for 1 hour, then cooled in an ice bath. The mixture was acidified with hydrochloric acid; the resulting precipitate was collected, rinsed with water followed by diethyl ether and allowed to dry to give 4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxylic acid (1.17 g). m.p. 225°-227°C.

出典

DOI: 10.6084/m9.figshare.5104873.v1特許: US05750702uspto-grants-1998_05