Studies On The Synthesis And Biological Activities Of Acyl Ureas And Acyl Thioureas Including Thiodizole

Plant growth regulator is a kind of organic compound with plant hormone function synthesized by artificial methods.In order to seek good plant growth regulators, we have modified the main structure of 1,3,4-thiadiazole and synthesisized 90 new compouds by Bioisosterism Principles and Substructure Link Wory.By consulting concerning literatures, we reviewed the biological activities and the synthesis methods of l,3,4-thiadiazoles,acyl urea,acyl thioureas.Target compounds I -, II are synthesized by nucleophilic addition of amino heterocycle with acyl isocyanates in anhydrous and aprotonic solvent. Target compounds III ^ IV are synthesized by nucleophilic addition of amino heterocycle with acyl isothiocyanates in anhydrous and aprotonic solvent.Reaction of 2-amino-1,3,4-thiadiazole with acyl isocyanates in anhydrous acetonitrile gave 21 new acyl ureas.Reaction of acyl isocyanates with 2-amino-5-thiol- 1,3,4-thiadiazole in anhydrous acetonitrile gave 23 new acyl ureas. Reaction of acyl isothiocyanate with 2-amino-1,3,4-thiadiazole in anhydrous acetonitrile gave 23 new acyl thioureas. At the same time , Reaction of 2-amino-5-thiol-l,3,4-thiadiazole with acyl isothiocyanate in anhydrous acetonitrile gave 23 new acyl thioureas.. IR. MS 1H NMR and elementary analysis comfirm their structure, their physical-chemical properties and spectrum data and synthesis condition of the target compounds were reported firstly. The main structures of the target compounds were as follows:I. N-(l,3,4-thiadiazol-2-yl)-N'-aroyl urea/ aryloxyacetyl ureaII. N-(5-thiol-l,3,4-thiadiazol-2-yl )-N'- aroyl urea/ aryloxyacetyl ureaThe plant growth regulating activity was tested by taking root and wheat sheath on the target compounds and the cucumber cotyledon expansion, preliminary results indicated that many of acyl thioureas exhibited higher auxin and cytokinin activity. The auxin activity of compound If 1Ih Ip Iq II d II e, II h II i II q IIId, IIIe, IIIi IVc, IVd IVh, IVq was weekly higher than that of p-indolyl acetic acid, The cytokinin activity of compound Id . If Ii II IIk , IIIc IIId was higher than that of 6-furylmethyl purine.The auxin and cytokinin activity of compound If, Ip Illd are both high.