反应详情

Ethyl [(5,6-dichloro-9a-cyclopropyl-3-oxo-1,2,9,9a-tetrahydro-3H-fluoren-7-yl)oxy]acetate (4.2 gm., 0.011 mole) is added to a solution composed of 20% aqueous sodium hydroxide solution (4.32 ml., 0.022 mole) and methanol (45ml.). The mixture is stirred and heated at reflux for two hours and then concentrated in vacuo at 50° C. The residue is dissolved in water (50 ml.) and made acid to Congo red paper with 6 normal hydrochloric acid. The solid that separates is removed by filtration, washed with water, then with a little methanol and finally with a little ether. After drying, the product is recrystallized from acetic acid to give pure [(5,6-dichloro-3-oxo-9a-cyclopropyl-1,2,9,9a-tetrahydro-3H-fluoren-7-yl)oxy]acetic acid.

1. temperatureheated
2. temperatureat reflux for two hours
3. concentrationconcentrated in vacuo at 50° C
4. dissolutionThe residue is dissolved in water (50 ml.)
5. customThe solid that separates is removed by filtration
6. washwashed with water
7. customAfter drying
8. customthe product is recrystallized from acetic acid