Reacción #632025

Ecuación de reacción

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

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe resulting mixture was refluxed for 2 h
2. 2
   Otrothe EtOH was removed by evaporation
3. 3
   ExtracciónThe residue was extracted with EtOAc twice (15 mL×2)
4. 4
   OtroThe aqueous layer was then transferred into a flask
5. 5
   Temperaturacooled with an ice-water bath
6. 6
   workup.ADDITIONHCl was added dropwise
7. 7
   workup.ADDITIONEtOAc (60 mL) was then added
8. 8
   Otrothe layers were separated
9. 9
   Extracciónthe aqueous layer was extracted with EtOAc
10. 10
    LavadoThe combined extracts were washed with brine
11. 11
    SecadoAfter being dried (MgSO4)
12. 12
    Filtraciónfiltered
13. 13
    Concentraciónconcentrated

Procedimiento

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+).

Fuente