反应详情

Methyl 5-benzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate (1.10 g.) in 30 ml. of methanol containing 2 molar equivalents potassium carbonate in 10 ml. of water is heated at reflux temperature for three hours. The methanol is removed in vacuo and water is added to the residue. The solution is extracted with ethyl acetate, the aqueous phase is cooled to 0° and made acidic with 20% hydrochloric acid. The solid which precipitates is collected by filtration, washed with cold water and dried in vacuo. The residue is crystallized from methanol-water to give 5-benzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid, m.p. 190° C.

1. temperatureat reflux temperature for three hours
2. customThe methanol is removed in vacuo and water
3. additionis added to the residue
4. extractionThe solution is extracted with ethyl acetate
5. temperaturethe aqueous phase is cooled to 0°
6. customThe solid which precipitates
7. filtrationis collected by filtration
8. washwashed with cold water
9. customdried in vacuo
10. customThe residue is crystallized from methanol-water