反应详情

A solution of 250 mg. of ethyl 5-benzoyl-7-bromo-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate in 8 ml. of methanol is treated under an atmosphere of nitrogen, with a solution of 200 mg. of sodium hydroxide in 1 ml. of water, maintaining the reaction mixture at room temperature for 1.5 hours. The methanol is then removed under reduced pressure and the basic solution which remains is diluted with 5 ml. of water and extracted with ether to remove any unsaponifiable product. The aqueous solution is acidified with 10% hydrochloric acid and extracted three times with ethyl acetate. The combined extracts are dried and evaporated to dryness under reduced pressure, and the residue crystallized from ethyl acetate-hexane, to give 5-benzoyl-7-bromo-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid.

1. customThe methanol is then removed under reduced pressure
2. additionthe basic solution which remains is diluted with 5 ml
3. extractionof water and extracted with ether
4. customto remove any unsaponifiable product
5. extractionextracted three times with ethyl acetate
6. customThe combined extracts are dried
7. customevaporated to dryness under reduced pressure
8. customthe residue crystallized from ethyl acetate-hexane