Synthesis and fungicidal activity of 3,6,9-triaryl-2-thioxothiazolo[ 4,5-<i>d</i>][1,3,4] oxadiazolo [2,3-<i>b</i>]pyrimidine and 3,10-diaryl-2-thioxothiazolo[ 4,5-<i>d</i>]pyrimido [2,1-<i>b</i>] pyrimidines

49-53Several 3,6,9-triaryl-2-thioxothiazolo[4,5-d][1,3,4]oxadiazolo[2,3-b] pyrimidines 4 and 3,10-diaryl-2-thioxodiazolo[4,5-d] pyrimido[2,1-b]pyrimidines 6 have been synthesised from the Michael adducts 3-aryl-5[{(5'-phenyl-1',3',4'-oxadiazol-2'-yl)amino}-(aryl)]-methyl-2-thioxo-4-thiazolidinone 3 and 3-aryl-5[(2-pyrimidylamino)aryl]methyl-2-thioxo-4-thiazolidinone 5, respectively which in turn have been prepared by the reaction of arylidenorhodanines 2 with 2-amino-5-aryl-1,3,4-oxadiazoles and 2-amino pyrimidine, respectively via Michael addition. The antifungal activity of the title compounds have been screened against Aspergillus niger and Penicillium citrinum. The results have been compared with standard fungicide Carbendazim under similar conditions