Synthesis of novel sulfonamides with anti‐Alzheimer and antioxidant capacities

Abstract A series of novel dopamine analogs incorporating urea and sulfonamide functional groups was synthesized from 3,4‐dimethoxyphenethylamine. The reaction of 3,4‐dimethoxyphenethylamine with N , N ‐dimethylcarbamoyl chloride, followed by the sulfonyl chlorination of the urea derivative, gave benzene‐1‐sulfonyl chloride 9 , which was reacted with NH 3 (aq) or N ‐alkyl amines to give related sulfonamides. The O ‐demethylation reaction of the subsequent compounds with BBr 3 afforded four novel phenolic dopamine analogs including sulfonamide and urea in the same structure. The anticholinergic and antioxidant effects of the synthesized compounds were examined. Compound 13 exhibited inhibition at the micromolar level for both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The IC 50 value of 13 was calculated as 298 ± 43 µM for AChE and 321 ± 29 µM for BChE. The antioxidant and antiradical effects of the molecules were investigated by five different methods. Among the synthesized compounds 10–18 , the best antioxidant and antiradical activities belong to the phenolic compounds 15 – 18 . Compounds 16 and 18 have a higher reducing power than the standards used, that is, butylated hydroxytoluene, butylated hydroxyanisole, Trolox, and α‐tocopherol, for Fe 3+ –Fe 2+ and Cu 2+ –Cu + reducing activities. For the DPPH• radical scavenging method, compounds 16 – 18 have a much better scavenging power than the standard molecules. In addition, it has been determined by the induced‐fit docking method that compound 13 is well‐fitted in the active site of the enzymes. ADME studies reveal that the pharmacokinetic and physicochemical properties of all synthesized compounds are within an acceptable range.