Pyrrole-2-Carboxylic Acid → 2-[2-(1H-Pyrrol-2-ylcarbonyl)-1H-pyrrol-1-yl]-1H-isoindole-1,3(2H)dione

Participants

Reaction Conditions

Reaction Steps

To a suspension of pyrrole-2-carboxylic acid (5.55 g) in 500 ml of DCM was added oxalyl chloride (8.7). The reaction mixture was heated under reflux for 1 hour, cooled to -10° C., and tin (IV) chloride (5.85 ml) was added. After stirring the mixture at -10° C. for 30 minutes, 2-(1H-pyrrol-1-yl)-1H-isoindole-1,3(2H)dione (10.6 g) was added in four portions over a period of 30 minutes, followed by stirring at -10° C. for additional 30 minutes. The reaction mixture was then poured into 500 ml of water and extracted with DCM. The combined extracts were washed with 1N sodium hydroxide solution, 1N sulfuric acid, and finally with water. The dried (magnesium sulfate) organic phase was filtered and evaporated in vacuo. The residue was tritated with DCM, affording the product as a powder (10.55 g), mp 204°-206° C.

Provenance & Evidence