Synthesis And Property Studies Of Biologically Active Novel Imidazolones

Many azole compounds have been found to show widespread biological activities. Some of them have been used as fungicide, herbicide, pestcide and medicine. In this paper, we studied the synthesis of novel imidazolones by utilizing aza-Wittig reaction. The spectral properties and biological activities of imidazolones were also researched and some of them were found to show good fungicidal activities. One hundred and fifteen unreported imidazolones in six series were synthesized. It may be summarized as follows:1. A general new synthetic method to 2-dialkylamino-5-arylidene-4H-imidazol-4-ones was proposed. This synthetic method has the advantages of easily accessible starting material, mild condition and good yields. The reaction of carbodiimides 2 with various nucleophiles was researched. Some of the gualidene-type intermediates were isolated and the possible mechanism was suggested.2. The selectivity of cyclization of carbodiimide 2 with primary amine was studied and the result showed that the anomalous product being cyclized from arylamino group was formed preferencially. This is probably due to the geometry of the intermediate.3. The cyclization of carbodiimide 2 with 1H-1, 2, 4-triazole in presence of solid potassium carbonate was studied firstly. The interesting color change was observed during the reaction process. The condition for cyclization was researched.4. The cyclization of carbodiimide 2 with substituted phenol in presence of solid potassium csrtjonaic was studied TiisX'iy. Tne resuYls show that It is a new mM method fOT preparing of 2-aryloxyimidazolones.5. 2-Alkyl(aryl)thio-4H-imidazol-4-ones were synthesized from consecutive aza-Wittig reaction. The condition of the reaction and the spectral properties of the products were studied.6. The biological activities of partial imidazolones were studied. The results showed that they did not exhibit obviously herbicidal activity but fungicidal activity. Twenty-one of them exhibited 100% inhibition of partial fungi in 50mg/L. The best one was compound12g which exhibited 100% inhibition of Pyricularia oryzae, Pellicularia sasakii, Fnsarium oxysporum, Physalospora piricola and Gibberella zeae as well as 81% inhibition of Cercospora asparagagas. The next was compounds 17r and 17s which exhibited 100% inhibition of Pyricularia oryzae, Pellicularia sasakii, Cercospora asparagagas and Physalospora piricola hi 50mg/L.