One-Pot Synthesis of 2-Substituted 5-Arylidene-1-alkyl-4-imidazolones and Study of Their Anticholinesterase and Antiradical Activity

A one-pot method was developed for the synthesis of 2-substituted 5-arylidene-1-alkyl-4-imidazolones using N-trimethylsilylimidazole. Two synthesis approaches were considered: (1) starting from 4-arylidene-5(4H)-oxazolones and (2) starting from N-substituted α,β-dehydroamino acids amides. It was shown that, in general, the one-pot synthesis method leads to higher yields of 2-substituted 5-arylidene-1-alkyl-4-imidazolones than the two-step method with the intermediate preparation of the N-substituted α,β-dehydroamino acid amide and its dehydration. N-Trimethylsilylimidazole was proposed as an effective reagent for the synthesis of 4(H)-imidazol-4-ones from 4-arylidene-5(4H)-oxazolones under one-pot synthesis conditions. Optical, antiradical and cholinesterase inhibitory properties of the synthesized 2-substituted 1-alkyl-4-imidazolones were studied.