SOME CYCLIZATION REACTIONS WITH 2-(4-OXOTHIAZOLIDIN-2-YLIDENE) ACETONITRILE WITH Α-Β UNSATURATED NITRILE COMPOUNDS

A novel 2- Cyanomethine- 4,5dihydro-4-oxo-5-(2,4dichlorophenyl) methylidine 1,3 thiazole (2) was obtained via the reaction of 4-thiazolidinone (1) with 2,4 dichloro- benzaldehyde .Treatment of 4-thiazolodinone derivatives(2) with 2,4 dichlorobe-nzaldhyde afforded 2,5-bis arylmethylidine derivatives (3a-d). Cyclization of compound (2) with various α-Cyanocinnamonitriles(4a-c) afforded the corresponding thiazolopyrid-ine enaminonitrile derivatives (5a-c). Reaction of compound (2) with α-ethoxycarbonyl cinnamonitriles (7a-c) gave the corresponding thiazolo[3,2-a]pyridine enaminoester deri-vatives (10a-c) . Also α-formamidocinnamonitriles (11a-c) were reacted with compound (2) and gave thiazolo [3,2-a] pyridine derivatives (12a-c). The reaction of (5a) with hydrazine hydrate, carbon disulphide in pyridine and malononitrile afforded the corres-pondding thiazolo pyridine and thiazolonaphthyridine derivatives (15),(16) and (17); respectively.