Reacción #1621598

Ecuación de reacción

hydrochloric acid

3,4-dihydroxyphenylacetic acid

1,3-dibromopropane

potassium hydroxide

→

title compound

Rendimiento 23.0%

(Benzodioxepan-7-yl)acetic acid

Rendimiento 23.0%

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas heated
2. 2
   Temperaturaunder reflux for 17 hours
3. 3
   Extracciónextracted several times into methylene chloride
4. 4
   SecadoThe combined organic extracts were dried over magnesium sulphate
5. 5
   Otroevaporated
6. 6
   OtroThe residue was purified by chromatography on silica (75 g)
7. 7
   Otroevaporated
8. 8
   Extracciónextracted into 5% aqueous sodium carbonate solution
9. 9
   ExtracciónThe basic extract
10. 10
    Lavadowas washed with methylene chloride
11. 11
    Extracciónextracted into methylene chloride
12. 12
    ExtracciónThe organic extract
13. 13
    Secadowas dried over magnesium sulphate
14. 14
    Otroevaporated

Procedimiento

A mixture of 3,4-dihydroxyphenylacetic acid (5.0 g), 1,3-dibromopropane (7.2 g) and potassium hydroxide (7.3 g) in water (25 ml) was heated under reflux for 17 hours, acidified to pH 1 with 2M hydrochloric acid and extracted several times into methylene chloride. The combined organic extracts were dried over magnesium sulphate and evaporated. The residue was purified by chromatography on silica (75 g) using methylene chloride plus 0-2% acetic acid as the eluant. Appropriate fractions were combined and evaporated and the residue was taken up in methylene chloride and extracted into 5% aqueous sodium carbonate solution. The basic extract was washed with methylene chloride, acidified to pH 1 with 5M hydrochloric acid and extracted into methylene chloride. The organic extract was dried over magnesium sulphate and evaporated to give the title compound as a colourless solid (1.4 g, 23%), m.p. 99°-101°.

Fuente