ABSTRACT A metal‐free, Ugi‐type dearomatization strategy for the efficient synthesis of dihydrophthalazine derivatives is described. This transformation enables the direct and efficient assembly of dihydrophthalazine‐1‐carboxamide scaffolds under mild conditions. The optimized process accommodates a broad range of substrates, including acyl chlorides, chloroformates, and both aromatic and aliphatic isocyanides, affording the desired products in good yields. This method offers notable advantages such as atom economy, operational simplicity, and wide functional group tolerance, providing efficient access to biologically relevant dihydrophthalazine frameworks.
Xu et al. (Tue,) studied this question.