Hetero Diels-Alder Synthesis and Fungitoxicity of New 1,3,4-Thiadiazolo[3,2-a]-s-triazine-5(H)-thiones
摘要:
Hetero Diels-Alder synthesis involving conjugated azomethines, 5-(arylideneamino)-2-mercapto-1,3,4-thiadiazoles IIa-c, as dienes (azadienes) and aryl isothiocyanates as dienophiles affords 2,6,7-trisubstituted 6,7-dihydro-1,3,4-thiadiazolo[3,2-a]-s-triazine-5(H)-thiones IIIa-f. The azomethines IIa-c on ethylation followed by hetero Diels-Alder reaction furnish 6,7-diaryl-2-(ethylthio)-6,7-dihydro-1,3 thiadiazolo[3,2-a]-s-triazine-5(H)-thiones IVa-f. Fungitoxicities of the compounds II-IV were evaluated in vitro aginst Aspergillus niger and Fusarium oxysporum. Some of the compounds displayed activities comparable with that of the commercial fungicide Dithane M-45. Structure-activity relationships for the screened compounds are discussed.
Hetero Diels-Alder Synthesis and Fungitoxicity of New 1,3,4-Thiadiazolo[3,2-a]-s-triazine-5(H)-thiones
摘要:
Hetero Diels-Alder synthesis involving conjugated azomethines, 5-(arylideneamino)-2-mercapto-1,3,4-thiadiazoles IIa-c, as dienes (azadienes) and aryl isothiocyanates as dienophiles affords 2,6,7-trisubstituted 6,7-dihydro-1,3,4-thiadiazolo[3,2-a]-s-triazine-5(H)-thiones IIIa-f. The azomethines IIa-c on ethylation followed by hetero Diels-Alder reaction furnish 6,7-diaryl-2-(ethylthio)-6,7-dihydro-1,3 thiadiazolo[3,2-a]-s-triazine-5(H)-thiones IVa-f. Fungitoxicities of the compounds II-IV were evaluated in vitro aginst Aspergillus niger and Fusarium oxysporum. Some of the compounds displayed activities comparable with that of the commercial fungicide Dithane M-45. Structure-activity relationships for the screened compounds are discussed.