How is 2-Butyl-1H-isoindole-1,3(2H)-dione (CAS: 1515-72-6) typically synthesized?

2-Butyl-1H-isoindole-1,3(2H)-dione is commonly synthesized via the condensation of 2-butyldione with isoindole. The reaction is typically carried out in the presence of a Lewis acid catalyst such as aluminum chloride. The selectivity and yield are high, with a purity of over 95% being achievable. The reaction is exothermic and should be performed in a well-ventilated area to prevent the accumulation of toxic fumes.