Structure-Based Hybridization, Conventional and Microwave Irradiated Synthesis, Biological Evaluation and Molecular Docking Studies of New Compounds Derived from Thiomorpholin

Background: The amine 2 obtained via two steps starting from thiomorpholine was converted into the corresponding 1,3-thiazole (4), arylmethileneamino (5a- d) and hydrazide (7) derivatives using conventional and also microwave techniques. The synthesis of 1,3,4-oxadiazole (8), arylidenenhydrazide (9a-c) and carbothioamides (10a,b) was performed with the treatment of 7 with CS2, suitable amines and suitable isothiocyanates, respectively. Method: Moreover, the treatment of compounds 10a, b with ethylbromoacetate, 2-bromo-1-(4-chlorophenyl) ethanone, conc. H2SO4 and NaOH yielded the corresponding, 1,3-thiazolidinone (11a,b), 1,3-thiazole (12), 1,3,4-thiadiazole (13a,b) and 1,2,4-triazole (14) derivatives, respectively, by either conventional or microwave mediated conditions. The one-pot three component synthesis of fluoroquinolone derivatives (15a,b and 16) was performed by condensation between compounds 8 and 14 with norfloxacine and ciprofloxacine under conventional or microwave irradiation conditions. Results: The effects of different catalysts, solvents and microwave powers on conventional and microwave-prompted reactions was also examined. The synthesized compounds were screened for their antimicrobial, enzyme inhibition and antioxidant activities. Molecular docking of some of the synthesized compounds into the active sites of lipase, alpha-glucosidase and urease was also carried out in order to predict the binding affinity and non-covalent interactions between them.