Methanol → 5-Benzoyl-7-bromo-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid

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Reaction Steps

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.

Provenance & Evidence