Herein, we report the synthesis, characterization, and catalytic evaluation of cobalt hydroxide chloride [Co₂(OH)₃Cl] in the solvent-free synthesis of 2-substituted 2,3-dihydroperimidines. The presented method aligns with several green chemistry principles, offering operational simplicity, purification by recrystallization, no by-product formation, high yields (64–99%), and short reaction times. A total of 16 dihydroperimidines were synthesized to demonstrate substrate scope versatility. Additionally, the catalyst was successfully recycled and reused in multiple cycles without significant loss. Its robustness was further confirmed by gram-scale synthesis, achieving an 89% yield.