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Paper | Regular issue | Vol 26, No. 3, 1987, pp.689-697
Published online, 1st January, 1970
DOI: 10.3987/R-1987-03-0689
Transformations of 1,2,4-Thiadiazolo[2,3-x]azines

Bozidar Koren, Branko Stanovnik, and Miha Tisler

*Department of Chemistry, E. Kardelj University, Murnikova 6, 61000 Ljubljana, Slovenia


Hydrolysis of 1,2,4-thiadiazolo/2,3-c/pyrimidine derivative 2 produced cyanoaminopyrimidine 4, while treatment of 1,2,4-thiadiazolo/2,3-b/ pyridazine 5 with hydrazine hydrate gave thiourea derivative 7. 1,2,4-Thiadiazolo/2,3-a/pyridine 8 and 1,2,4-thiadiazolo//2,3-a/pyrazine 9 gave by alkaline hydrolysis the corresponding pyridopyrimidine 10 and pteridine 11, respectively . The compound 10 was converted with phenacyl bromide into 14 and further cyclized in PPA into pyrido/2,3-d/ thiazolo/2,3-a/pyrimidine 15. Pyrazinylthiourea derivative 16 was cyclized in acidic solution into thiazolo/4,5-b/pyrazine 17, which was converted by hydrolysis and decaroxylation into amino derivative 20. This gave with ethyl acetoacetate pyrazino/2’,3’:4,5/thiazoIo/3,2-a/pyrimidine 23. 1,2,4-Thiadiazoloazines 24 and N-ethoxycarbonyl-N ’-azinylthioureas 25 were transformed with hydrogen peroxide into urea derivatives 26.