Synthesis And Biological Activity Of Camphor-based Benzamide And Camphor-based Phenyl Thiourea Compounds

Camphor is a nonwood forest product with bicyclic monoterpene structure,and is also a natural and preponderant resource of China.Camphor and its derivatives show a wide range of biological activities.Various bioactive derivatives can be synthesized by structural modification of the molecule of camphor.In this thesis,two types of novel camphor-based derivatives with potential biological activity,camphor-based benzamides and camphor-based phenyl thioureas,were designed and synthesized by modification reactions of carbonyl group in D-(+)-camphor,and by introduction of active amide and thiourea groups into the skeleton of D-(+)-camphor.This research aims at providing a new way for the deep development and utilization of camphor.In this thesis,camphoramine 3 was prepared by the reduction of camphoroxime 2 converted from D-(+)-camphor.Then,nine novel camphor-based benzamide compounds 4a?4i were synthesized by the N-acylation reaction of camphoramine 3 with a series of substituted benzoyl chlorides.Besides,ten novel camphor-based phenyl thiourea compounds 6a?6j were synthesized by the reaction of camphoramine 3 with a series of substituted phenyl isothiocyanates.The synthetic conditions of the target compounds were investigated preliminarily.The target compounds were analyzed and characterized by means of FT-IR,1H NMR,13C NMR,and LC-MS techniques.The herbicidal activity of the target compounds,camphor-based benzamide compounds 4a?4i and camphor-based phenyl thiourea compounds 6a?6j,was evaluated by barnyard grass beaker method and rape petri dish method.It was found that,at the concentration of 100 ?g·mL-1,compounds 4d(R=p-Cl),4g(R=p-F),and 4a(R=p-H)exhibited inhibition rate of 97.4%,92.3%,and 89.0%(A-class activity level),respectively,against rape root(Brassica campestris).Compound 4b(R=p-CH3)showed inhibition rate of 70.0%(B-class activity level)against barnyard grass(Echinochloa crusgalli(L.)).Compound 6i(R=p-Br)displayed inhibition rate of 60.2%(B-class activity level)against rape root(Brassica campestris).Compound 4d(R=p-Cl)is a lead compound worthy of deep research.The fungicidal activity of all the target compounds,4a?4i and 6a?6j,was evaluated by in vitro method against Fusarium oxysporum f.cucumerinum,Physalospora piricola,Alternaria solani,Cercospora arachidicola,and Gibberella Zeae.It was found that,at the concentration of 50 ?g·mL-1,seven camphor-based benzamide compounds exhibited inhibition rate of greater than 90%(A-class activity level)against Physalospora piricola,in which compound 4e(R=o-Cl)had the best inhibition rate of 97.5%.Compounds 4g(R=p-F)and 4e(R=p-Cl)showed inhibition rate of 95.7%(A-class activity level)and 81.4%(B-class activity level)against Gibberella Zeae,respectively.Six camphor-based phenyl thiourea compounds exhibited inhibition rate of greater than 70%(B-class activity level)against Physalospora piricola,in which compound 6f(R=m-OCH3)had the best inhibition rate of 83.9%.Compound 6d(R=p-CH3)showed inhibition rate of 82.2%(B-class activity level)against Alternaria solani.Compounds 4e(R=o-Cl)and 4g(R=p-F)are lead compounds worthy of deep research.