Synthesis of 5-arylmethylidene-3-(arylmethylideneamino)thiazolidine-2,4-diones via triazine ring cleavage of tetrahydroimidazothiazolotriazinediones and their reactions with azomethine ylides

Cleavage of 1,3-dimethyl-3,3a,9,9a-tetrahydroimidazo[4,5- e ]thiazolo[3,2- b ][1,2,4]triazine-2,7(1 H ,6 H )-diones upon treatment with aromatic aldehydes has been shown to afford ( Z )-5-arylmethylidene-3-(( E )-arylmethylideneamino)thiazolidine-2,4-diones bearing two identical or different arylmethylidene fragments at the exocyclic nitrogen atom and at position 5 of thiazolidine cycle. 1,3-Dipolar cycloaddition reaction of thiazolidine-2,4-dione derivatives with azomethine ylide generated from isatin and sarcosine gave diastereomerically pure dispiro[indole-3,2′-pyrrolidine-3′,5″-thiazolidine]-2,2″,4″-triones in good yields. Dispiro compound with two 4-methoxyphenyl fragments exhibited slight antiproliferative activity toward CCRF-CEM (leukemia) and CAKI-1 (renal cancer) cell lines.