Studies On Synthesis And Biological Activities Of Diphenyl Ethers

Diphenyl ether herbicides are widely used since the first diphenyl ether herbicide Nitrofen which was discovered by Rohm Haas America in 1960 opened up a new field of herbicides.The theme of today’s pesticides is "efficient,low toxicity and safety" which are the main features of diphenyl ether herbicides.So far,diphenyl ether herbicides still occupied an important position in the field of herbicides.In this paper,high-efficency herbicide Ethoxyfen as the lead compound,16 unreported and novel diphenyl ether compounds were designed by anologue synthesis,sub-structure and bioisosterism theory.Their structures were confirmed by LC/MS,1H NMR and IR spectra.According to the structure,the target compounds can be divided into the following categories:Diphenyl ethers with nitro I:I a:R1=H,R1=OCH(CH3)COOCH2CH3(S);I b:R1=H,R2=OCH(CH3)COOCH2CH3(R);I c:R1=H,R2= OCH-(CH3)COOCH3(S);Id:R1=H,R2=OCH(CHj)COOCH3(R);I e:R1=H.R2=OH;If:R1=H,R2=NHOCH2-C =CH;I g:R1=H,R2=OCH2COOCH2CH3;I h:R1=H,R2=NHSO2CH3;I i:R1=Cl,R1= OCH(CH3)COO-CH2CH3(S);I j:R1=Cl,R2=OCH(CH3)COOCH2CH3(R);I k:R1=Cl,R2= OCH(CH3)COOCH3(S);11:R1=Cl,R2= OCH(CH3)COOCH3(R);Diphenyl ethers with Sulfonyl II:Ⅱa:R1=SOCH3,R2=OCH(CH3)COOCH2CH3(S);Ⅱb:R1=SO2CH3,R2=OCH(CH3)COOCH2CH3(R);Ⅱc:R1=SOO2CH3,R2=OCH(CH3)COOCH3(S),Ⅱd:R1=SO2CH3,R2=OCH(CH3)COOCH3(R);Ⅱe:R1=NO2,R2= NHSO2-CH3;Bioassays of the synthesized compounds were tested according to the standard operation procedures of pesticides bioassay(SOP)established by National Engineering Research Center for Agrochemicals.Preliminary bioassay results showed that at a concentration of 2250 g a.i/ha,compound Ⅰa,Ⅰc,Ⅰd,Ⅰe,Ⅰb,If,Ⅰg and Ⅱe had 100%inhibition ratio against Abutilon theophrasti,Amaranthus spinosus and Chenopodium album,compound Ⅰa,Ⅰb,Ⅰg,Ⅱe had 90%inhibition ratio against Digitaria sanguinalis,Echinochloa crus-galli and Setaria viridis.Compound Ⅱe also had more than 95%inhibitory activity against Amaranthus spinosus and Chenopodium album at 2.5 g/mu.Compound I a still had 100%inhibitory activity against Abutilon theophrasti and Amaranthus spinosus at 1.25 g/mu.The insecticidal activity results showed that compound II possessed good insecticidal efficiency against Aphis fabae,especially compound Ⅱc had 90%mortality ratio at 500 mg/L.The structure-activity relationship based on biological activity for the target compounds was discussed.The law which was summarized can provide some theoretical guidance for designing such compounds in the future.