Cинтез 1,5-діарил-4-арилтіопіролідин-2-онів реакцією арилсульфенілювання N-ариламідів стирилоцтової кислоти

• Date: 2015
• Main Authors: Tsyzoryk, N. M., Danyliuk, I. Yu., Vaskevych, A. I., Vaskevych, R. I., Vovk, M. V.
• Format: Article
• Language: English
• Published: National University of Pharmacy 2015
• Subjects: аміди стирилоцтової кислоти; електрофільна внутрішньомолекулярна циклізація; арилсульфенілхлориди; піролідин-2-они; УДК 541.398.1 547.569.4 547.745
• Online Access: https://ophcj.nuph.edu.ua/article/view/ophcj.15.870
• Journal Title: Journal of Organic and Pharmaceutical Chemistry

The role of the electrophilic intramolecular cyclization (EIC) reaction of unsaturated carboxylic acid amides has been described for the design of arylthio-containing lactams and lactones. In order to identify the effect of the styryl moiety on regioselectivity of the electrophilic intramolecular cyclization process styryl acetic acid amides with electron-donating substituents in para-position of the styryl moiety have been studied. It has been found that these compounds react with phenyl and p-tolylsulfenylchlorides in nitromethane in the presence of lithium perchlorate as a “doping additive” to form 1,5-diaryl-4-arylthiopyrrolidin-2-ones with the yield of 60-66%. It is most likely that the reaction found includes the formation of the episulfonium cation stabilized by the perchlorate-anion followed by 5-endo-cyclization onto the nitrogen atom of the amide group. The structure of the compounds synthesized has been confirmed by their spectral parameters. In particular, the IR-spectra contain strong absorption bands C=O at 1703-1703 cm-1, and 1H NMR-spectra of the compounds obtained are characterized by two protons multiple shifts of the H3 pyrrolidine ring at 2.52-2.64 and 3.08-3.22 ppm, respectively, H4 proton multiple shifts at 3.61-3.76 ppm and H5 at 4.99-5.09 ppm. Formation of the pyrrolidine ring as a result of cyclization has been reliably proven by 13C NMR-spectra with the typical signals of carbon atoms: C3 (37 ppm), C4 (48 ppm), C5 (69 ppm) and C2 (172 ppm).