Synthesis And Fungicidal Activity Of 2-aryl(or 2-arylmethyl)pyrazinonoquinazoline Compounds

Amides,pyrazinones,quinazolines and imidazolines all have good biological activities,and have become one of the hot spots of drug and pesticide research.Therefore,this paper mainly designed and synthesized a series of novel2-arylpyrazazinonoquinazolines VI and 2-arylmethylpyrazinonoquinazoline VII,and a series of amides,which were characterized by ¹H NMR,¹³C NMR,and the single crystals of part of the compounds were determined by X-ray diffraction.The fungicidal activity of the synthetic compounds was tested.（1）Under the action of triethylamine,a series of 2-bromoacetyl aryl（methyl）amides I-1～I-20 were synthesized in a yield of 82%～96%by reaction of2-bromoacetyl bromide with aryl（methyl）amines.N-heterocyclic amides I-21～I-36were synthesized by reaction of 2-aminobenzothiazole or 2-aminobenzoimidazole with chloroacetyl chloride、bromoacetyl bromide、acetyl bromide and chloropropionyl chloride.（2）Under the action of triethylamine,2-bromoacetyl aryl（methyl）amines Ir eacted 2-aminobenzylamine（material ratio 1.0:1.2:1.5）in a mixed solvent of DMF and THF for 2h to produce a series of 2-（2-aminobenzyl）amino)aromatic（methyl）amine compounds II-1～II-20 in a yield of 46%～72%.（3）A series of N-（2-aminobenzyl）amino)-N′-aryl（methyl）-1,2-ethylenediamines III-1～III-20 were synthesized by reduction of 2-（2-aminobenzyl）amino)aryl（methyl）amines II with Li Al H₄ in 57%～90%of yield,and reaction material ratio of n（compound II）:n（Li Al H₄）=1.0:4.6,anhydrous THF as solvent,temperature 65℃,reaction time 3h.（4）The reaction of N-（2-aminobenzyl）amino)-N′-aryl-1,2-ethylenediamines III with ethyl glyoxalate yields 2-aryl-pyrazinonoquinazolines VI,but also in evitably generated 1-（2-aminobenzyl）-3-arylimidazolines IV and 3-（2-（aryl）amino）ethyl)quinazolines V.The optimum reaction conditions were as follows:the material ratio of compound III to ethyl glyoxate was 1:2.4,TEA（200%mol）as catalyst,toluene as solvent,and the reaction temperature 95℃,times 24 h.The total yield of compound VI,compound V,compound IV was 76%～85%.（5）A series of compounds VII-1～VII-20 were synthesized by the reaction of N-（2-aminobenzyl）amino)-N′-arylmethyl-1,2-ethylenediamines III with ethyl glyoxate or ethyl pyruvate in a total yield of 46%～80%.The material ratio of compound III to ethyl glyoxate was 1:2.4,and TEA（200%mol）as catalyst,toluene as solvent,reaction temperature 95℃,times 24 h.The results showed that products of the reaction N-（2-aminobenzyl）amino)N′-aromatic（methyl）-1,2-ethylenediamine III and ethyl glyoxylate were closely related to the groups linked to N atoms.When the substituent was arylmethyl,only pyrazinonoquinazolines VII were obtained.In addition to pyrazinonoquinazolines VI,quinazolines V and imidazolines IV are also formed when the substituent is aryl group.（6）The fungicidal activity of the compounds I、II、III、VI、VII was tested.Pyrazinonoquinazolines VI-4、VI-8、VII-3、VII-8、VII-12、VII-19和VII-20 showed good fungicidal activity against Sclerotonia sclerotiorum,with inhibition rates of70.9%、83.8%、64.2%、78.3%、75.2%、75.2%和78.9%,respectively,higher than that of chlorothalonil.Pyrazinonoquinazolines VII-9 showed 62.9%inhibition rates against Botrytis cinerea,respectively.Midazoline IV showed good fungicidal activity against Sclerotonia sclerotiorum,up to 80.5%,respectively,higher than that of chlorothalonil;Compound IV-5 showed 70.0%inhibitory activity against gibberella zeae.The quinazolines V-5 inhibited up to 80.5%against Sclerotonia sclerotiorum;Compound V-2 showed 65.0%inhibitory activity against gibberella zeae.Peterocyclic amides compounds I-22、I-24、I-33 and I-35 showed 100%inhibitory activity against Magnaporthe grisea.Compounds I-23、I-28 and I-34 showed 100%inhibitory activity against Magnaporthe grisea、Sclerotonia sclerotiorum and Pellicularia sasakii.2-（2-aminobenzyl）amino)aromatic（methyl）amine II-11、II-14and II-19 showed 91.8%inhibitory activity against Phytophythora capsici.The inhibition rate of compound II-13 against Magnaporthe grisea was 76.7%.The inhibition rates of compound II-18 against Sclerotonia sclerotiorum and Pellicularia sasakii were 74.5%and 68.8%.Substituent ethylenediamines III-14 had 91.7%inhibition rate against Sclerotonia sclerotiorum,and 84.2%inhibition rate against Pellicularia sasakii.The inhibition rate of compound III-10 against Sclerotonia sclerotiorum was 72.5%.Compound III-7 showed 67.7%inhibition against Botrytis cinerea.The inhibition rate of compound III-19 against Sclerotonia sclerotiorum was 85.0%.