Reaction of heteroaromatic o-aminonitrile with ethyl N-/bis(methylthio)methyleneamino acetate resulted in annelation of a thieno/3,2-e/imidazo/1,2-c/pyrimidine moiety in a one step process. /1,2,4/Triazolo/4,3-c/thieno/3,2-e/pyrimidine derivatives were prepared by initial treatment of o-aminonitrile with carbon disulfide, followed by methylation with methyl iodide and subsequent reaction with benzhydrazide and thiosemicarbazide, respectively. Hydrazinothieno/2,3-d/pyrimidine was prepared by cyclization of heteroaromatic o-aminoester with formamide, followed by chlorination and subsequent displacement with hydrazine. Treatment of the hydrazine derivative with acetylacetone, benzaldehyde and acetic anhydride afforded pyrazolylpyrimidine, benzylidenehydrazonopyrimidine and trizolopyrimidine derivatives, respectively. Some of these derivatives exhibited pronounced antimicrobial activity.Reakcijom heteroaromatskih o-aminonitrila s etil N-/bis(metiltio)metilenamino acetatom u jednom sintetskom koraku doΕ‘lo je do anelacije u tieno/3,2-e/imidazo/1,2-c/pirimidin. Derivati /1,2,4/triazolo/4,3-c/tieno/3,2-e/pirimidina pripravljeni su reakcijom o-aminonitrila s ugljikovim disulfidom, te metilacijom s metil-jodidom i naknadnom reakcijom s benzhidrazidom, odnosno tiosemikarbazidom. Hidrazinotieno/2,3-d/pirimidin je pripravljen ciklizacijom heteroaromatskog o-aminoestera s formamidom, te kloriranjem i supstitucijom s hidrazinom. Reakcijom hidrazinskog derivata s acetilacetonom, benzaldehidom ili anhidridom octane kiseline nastali su derivati pirazolilpirimidina, benzilidenehidrazonopirimidina, odnosno trizolopirimidina. Neki od tih derivata djeluju antimikrobno
