Borax Catalysed Domino Synthesis of Highly Functionalised Spirooxindole and Chromenopyridine Derivatives: X-Ray Structure, Hirshfeld Surface Analysis and Molecular Docking Studies

Borax efficiently catalysed the synthesis of a series of spirooxindole and chromeno[2,3-b]pyridine-3-carbonitrile derivatives in domino fashion via Knoevenagel condensation followed by Michael addition. This synthetic scheme is operationally simple, affording excellent yield and can be considered as an approach towards 'green chemistry'. In-silico docking studies of the synthesized molecules were carried to investigate the antitumor activity and to predict its binding affinity and orientation at the active site of human anaplastic lymphoma protein (Protein Data Bank (PDB): 2xp2). Molecular docking studies indicated that 2-amino-5'-chloro-7,7-dimethyl-2',5-dioxo- 5,6,7,8-tetrahydrospiro[chromene-4,3'-indoline]-3-carbonitrile (1 e) and 2'-amino-5-chloro-2,5'-dioxo-5'H-spiro[indoline-3,4'pyrano[3,2-c]chromene]-3'-carbonitrile (2 b) appeared to show strong interactions at the receptor active site with predicted binding energy of 8.47 kcal/mol and 9.19 kcal/mol respectively. A detailed analysis of topology of the compounds 1 e and 2 b were also determined by X-ray crystallography and Hirshfeld surface analysis to get an insight of the packing and intermolecular interactions in their molecular structure.