Methanol → 5-(2-thenoyl)-1,2-dihydro-6-methyl-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid

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Reaction Steps

A solution of 500 mg. of isopropyl 5-(2-thenoyl)-1,2-dihydro-6-methyl-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate in 15 ml. of methanol is treated with a solution of 1.05 g. of potassium carbonate in 8 ml. of water. The reaction mixture is refluxed under nitrogen atmosphere for 3 hours, cooled, and evaporated to dryness. The residue is taken up in 10 ml. of 10% aqueous hydrochloric acid and 50 ml. of water and the resultant mixture extracted with ethyl acetate (3 × 50 ml.). The combined extracts are dried over magnesium sulfate and evaporated to dryness under reduced pressure, to give 5-(2-thenoyl)-1,2-dihydro-6-methyl-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid [(A), R = CH3, R1 = H, X = S], having a melting point of 166° C.

Provenance & Evidence