This study reports the synthesis and characterization of novel 4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (THBTC) derivatives. Compounds 3–12 were synthesized via N-alkylation of compound 2 with various alkyl, benzyl, and heterocyclic halides. Notably, compound 11 was formed through an unexpected intramolecular cyclization mechanism. Furthermore, derivatives 14–24, incorporating a 1,2,3-triazole ring, were prepared using a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between compound 12 and readily synthesized azides. All derivatives were characterized by ¹H NMR, ¹³C NMR, and mass spectrometry. Single-crystal X-ray diffraction analysis of derivatives 11 and 25 confirmed their molecular structures and revealed the presence of intramolecular cyclization and tautomerism. The crystal arrangements exhibited a range of noncovalent interactions, including N—H···O, C—H···O, N—H···π, and π-π stacking, which contributed to their stability in the solid state. A computational study using QTAIM and IGM topological analyses was conducted, offering insights into the nature and strength of intermolecular noncovalent interactions. Additionally, conceptual DFT calculations at wB97X-D/cc-pVTZ level provided insights into the global and local reactivity properties of both compounds. Molecular docking studies were conducted to evaluate their binding characteristics as inhibitors of the JNK3 target protein. Finally, in silico ADME (absorption, distribution, metabolism, and excretion) predictions were performed to assess their druglikeness and bioavailability. This work aims to advance our understanding of the chemistry, and potential applications of 4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (THBTC) derivatives.