Hydrolysis of 5-neopentoxy-1, 3-diiminoisoindoline gave 5-neopentoxy-1 H-isoindole-1, 3 (2 H)-dione (4-neopentoxyphthalimide), which, on treatment with Lawesson's reagent, yielded the thiophthalimides, 5-neopentoxy-1 H-isoindole-1, 3 (2 H)-dithione, 2, 3-dihydro-6- neopentoxy-3-thioxo-1 H-isoindol-1-one, and 2, 3-dihydro-5-neopentoxy-3-thioxo-1 H- isoindol-1-one. Attempted S-alkylations of the thiophthalimides resulted in the formation of ...