The synthesis of new Betti base derivatives as spirodiclofen analogues is proposed as a promising alternative for the management of Tetranychus urticae, a pest that has become increasingly problematic in recent years due to the development of resistance and the overuse of synthetic acaricides. In this study, a series of compounds analogous to both spirodiclofen and the natural products caulersin and caulerpine were synthesized via the Biginelli multicomponent reaction, with the aim of evaluating their acaricidal activity against T. urticae under laboratory conditions. A total of five novel Betti base analogues were synthesized, each with chemical yields exceeding 80%. All compounds exhibited significant acaricidal activity against T. urticae. In adults and nymphs, Betti base derivatives H-108, H-110, H-115, and OGH-1 induced mortality rates ranging from 80% to 95%. Regarding egg mortality, H-107 and H-108 caused over 80% mortality. These findings indicate that certain Betti base derivatives hold potential for the effective control of T. urticae, supporting their possible integration into pest management strategies.