Benzothiazolyl- and benzimidazolyl-substituted 1-iminoisoindolines: synthesis, mechanistic studies, and crystal structure determination

New benzothiazolyl- and benzimidazolyl-substituted 1-iminoisoindolines are prepared in the reaction of o -phthalaldehyde and substituted 2-aminobenzothiazoles and 2-aminobenzimidazoles. The optimization of these reactions is discussed, and the reaction mechanisms are proposed based on the experimental findings. Isoindolines with other heterocyclic substituents are prepared as a confirmation of the proposed mechanisms. Molecular and crystal structures of several prepared compounds are determined by a single crystal X-ray diffraction. These structures are found to be in line with projections based on the chemical and spectroscopic properties, and thus offer an additional confirmation of the proposed reaction mechanisms. Graphical abstract