Poly(Ethylene Glycol) Supported Aza-Wittig Reaction In Imidazolinones Synthesis

Imidazolones have been found to show fungicidal, herbicidal, pestcidal and medicinal activities, and have been applied foreground extensively. In order to find a more effective synthetic method of imidazolones, aza-Wittig reaction from poly(ethylene glycol) (PEG) supported and traditional aza-Wittig reaction were applied in this paper. It may be summarized as follows:1.Twenty-seven unreported imidazolones in two series were synthesized. The structures of the target compounds (I_6a-I_6n, I_6a'-I_6g', II_16a-II_16l) have been confirmed by ¹H NMR, EI-MS, IR, elementary analysis and the X-ray crystallography for I_6a', I_6j, II_16g.2. Poly(ethylene glycol) supported iminophosphorane aza-Wittig reaction was firstly studied. By contrast with trational methods, it has the advantages of easily isolating the intermediates and it was facile. The application of aza-Wittig reaction in organic synthesis was enlarged greatly.3.The reactions of carbodiimide 4 reacted with primary amines were studied further. The results showed that carbodiimide 4 reacted with primary amines bearing large steric goups to provide 2-alkylamine-1-alry-1H-imidazol-5 (4H) -ones, while reacting with non-sterically primary amines give rise to 3-alkyl-2-(alryimino)-imidazol-4-ones. However, as reacting with primary amines like isopropyl, cyclohexylamine, both of the products were produced.4.The cyclization reactions of carbodiimide 14 with chiral amide ethyl ester was firstly studied. The results showed that the carbodiimide 14 reacted quickly with amide ethyl ester at room temperature. The product was identified as a five-membered ring compound. The reaction could not continue to cyclize when adding sodium ethanol. Then we synthesized 3-(ethoxycarbonyl) methylene-2-(alryimino)-imidazol-4-ones via aza-Wittig reaction in very mild conditions.