[Substances with central nervous system activity. Derivatives of 2,3,5,9b-tetrahydro-1,3-dioxo-1H-imidazo[5,1-a]isoindole-5 -carboxylic acid].

The AA. describe the synthesis of some methyl esters of 2-alkyl or 2-aryl-2,3,5, 9b -tetrahydro-1,3-dioxo-1H-imidazo[5,1-a] isoindol -5-carboxylic acids and of the corresponding acids. From these acids some aliphatic and heterocyclic amides were synthesized. The pharmacological data of these compounds are also reported.