反応 #487587

反応方程式

ethyl 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetate

potassium hydroxide

→

2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetic acid

溶媒

ethanol

反応条件

後処理

1. 1
   温度the resulting mixture was refluxed for 2 h
2. 2
   その他the EtOH was removed by evaporation
3. 3
   抽出The residue was extracted with EtOAc twice (15 mL×2)
4. 4
   その他The aqueous layer was then transferred into a flask
5. 5
   温度cooled with an ice-water bath
6. 6
   workup.ADDITIONHCl was added dropwise
7. 7
   workup.ADDITIONEtOAc (60 mL) was then added
8. 8
   その他the layers were separated
9. 9
   抽出the aqueous layer was extracted with EtOAc
10. 10
    洗浄The combined extracts were washed with brine
11. 11
    乾燥After being dried (MgSO4)
12. 12
    ろ過filtered
13. 13
    濃縮concentrated

実験手順

The compound of formula (Db), ethyl 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetate, (6.6 g, 26.8 mmol) was dissolved in ethanol (EtOH) (30 mL), then 10% potassium hydroxide (KOH) aqueous solution (37.5 mL, 67 mmol) was added and the resulting mixture was refluxed for 2 h. After cooling to ambient temperature, the EtOH was removed by evaporation. The residue was extracted with EtOAc twice (15 mL×2). The aqueous layer was then transferred into a flask and cooled with an ice-water bath, con. HCl was added dropwise to adjust pH to about 2.0. EtOAc (60 mL) was then added, the layers were separated, and the aqueous layer was extracted with EtOAc. The combined extracts were washed with brine. After being dried (MgSO4), filtered, and concentrated, the compound of formula (Dc), 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetic acid, was obtained as an orange oil (5.7 g, 97%); 1H NMR (300 MHz, CDCl3) δ: 7.71-7.68 (m, 1H), 7.41-7.20 (m, 3H), 3.37-3.31 (m, 1H), 3.12-2.91 (m, 3H), 2.57-2.49 (m, 1H), 2.15-1.90 (m, 2H), 1.75-1.62 (m, 2H); LC-MS: purity: 100%; MS (m/e): 219 (MH+).

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