Synthesis of 4-trifluoromethyl-3,4-dihydro-1,3,5-triazino[2,1-a]isoindol-2-ones by cyclocondensation of 1-aryl-1-chloro-2,2,2-trifluoroethyl isocyanates with 3-amino-1-arylimino-1H-isoindoles

4-Trifluoromethyl-3,4-dihydro-1,3,5-triazino[2,1-a]isoindol-2-ones were prepared by reaction of 1-aryl-1-chloro-2,2,2-trifluoroethyl isocyanates with 3-amino-1-arylimino-1H-isoindoles in the presence of triethylamine. In some events alongside the main product isomeric 2-trifluoromethyl-2,3-dihydro-1,3,5-triazino[2,1-a]isoindol-4-ones were obtained. The regioselectivity of the reaction is affected by sterical and electronic characteristics of substituents and by temperature.