Synthesis And Fungicidal Activity Of Amidyl Substituted Benzoxazinones And Quinazolinones

Benzoxazinone,quinazolinone and amide compounds are widely used in m edicine,pesticide,chemical industry and other fields because of their extensive biological activities.Therefore,people pay more and more attention to the syn thesis and research of quinozolinones and benzoxazinones.In this paper,a seri es of novel 3-amidoquinozoline-2-ones and 3-（substituted benzothiazolyl）-1,3-ben zoxazinone compounds were designed and synthesized,and their structures wer e characterized by ¹H NMR,¹³C NMR and IR.Their fungicidal activities were also evaluated.（1）Under the action of TEA,N-aryl-2-bromoacetamides III-1～III-15 were synthesized in 77%～97%yields by reaction of bromoacetyl bromide and arom atic amine or benzylamine.Similarly,N-（substituted benzothiazolyl）-2-bromoacet amides VI-1～VI-3 were synthesized in 73%～81%yields from bromoacetyl bro mide and aminobenzothiazole and its derivatives.（2）A series of N-aryl-2-（（2-aminobenzyl）amino）acetamides II-1～II-15 were synthesized in yields of 38%～76%at 65℃with N-aryl-2-bromoacetamide C ompounds III and o-aminobenzylamine as raw materials,TEA as base and DM F/THF（V:V=1:1）as solvent.When the substituent on the benzene ring is an electron donor one,the yields of the reactions abided the order:4->2->3-position,while the substituent is an electron withdrawing one,the yields fol lowed the trend:4->3->2-position.The effects of alkali and its loading,re actants ratio,solvent,temperature and time on the reaction were explored,and the optimized reaction conditions were obtained.（3）Reaction of N-aryl 2-（（2-aminobenzyl）amino）acetamide compound II wi th triphosgene under the action of TEA gave 3-amidoquinozoline-2-ones I-1～I-15 in yields of 41%～84%.When the substituent on the benzene ring was an electron-releasing group,the yield was the highest when it was at 4-opposite,b ut when the substituent was an electron-withdrawing group,it followeded the tr end of 3->4->2-position.The effects of alkali and its loading,reactants rat io,solvent,temperature and time on the reaction were discussed,and obtained the optimized reaction conditions.（4）Under the action of Na₂CO₃,N-（substituted benzothiazolyl）-2-bromoacet amide VI reacted with o-hydroxybenzylamine at 65℃to produce N-（benzothia zolyl-2-yl）-2-（（2-hydroxybenzyl）amino）acetamides V-1～V-3 in yields of 36.2%～46.7%.The effects of alkali and loading,reactants ratio,solvent,temperature an d time on the reaction were discussed,and obtained the optimized reaction con ditions.（5）3-（Substituted benzothiazolyl）-1,3-benzoxazinones IV-1～IV-3 were synth esized by the reaction of N-（benzothiazolyl）-2-（（2-hydroxybenzyl）amino）acetami de V with triphosgene under the action of TEA in 30.3%～40.9%yields.（6）The fungicidal activity of compounds I,II and IV-VI was tested,an d compounds showed moderate to excellent activity.Compound VI-2 showed 100%activity for all tested fungi pathogens at the concentration of 50g/ml.Co mpound VI-1 showed 100%activity against five pathogens except Gibberella z eae.Compound VI-3 demonstrated 100%activity against Phytophythora capsici and Pellicularia sasakii.Compound II-14 exhibited 81%,98%,95%and 81%activity against Gibberella zeae,Magnaporthe grisea,Sclerotinia sclerotiorum an d Botrytis cinerea,respectively.The inhibition rate of compound I-14 against Gibberella zeae was 75%.The activity of the above compounds is all higher t han that of chlorothalonil,which is worthy of further study.