Purines tetrazolo pyrimidine

Tetrazolo[l,5-c]pyrimidine, 8-amino-7-chloro-purine synthesis from, 5, 591 Tetrazolopyrimidines... 

Pyrimidines have attracted the attention of organic chemists and biochemists because of their role in biological systems, particularly in nucleic acids, which contain pyrimidines and purines as the main nucleobases. Consequently, the aza analogs of purines, mainly the triazolo and tetrazolo[.r,y-zjpyrimidines, also are important. 

Tetrazolo[l,5-c]pyrimidine, 8-amino-7-chloro-purine synthesis from, 5, 591 Tetrazolopyrimidines purine synthesis from, 5, 591 Tetrazolo[ 1,5-a]pyrimidines cycloaddition reactions, 5, 881 reactions, 5, 880 ring opening, 5, 880 structure, 5, 859, 860 synthesis, 5, 902 thermolysis, 5, 881 Tetrazolo[ 1,5-c]pyrimidines hydrogenation, 5, 881 reactions, 5, 881 structure, 5, 859, 860 synthesis, 5, 902 thermolysis, 5, 881... 

A similar method was applied when preparing exclusively the [5,1-/)]-isomer from 2-hydrazino-l-methylpurinone. A useful access involved the treatment of nitrous acid and 4-amino-2-hydrazinopyrimidine-5-carbohydrazide (315) giving 5-amino-6-azidocarbonyltetrazolo[l,5-u]pyrimidine 316. Subsequent heating and cyclization converted it to the corresponding isocyanate 317 and tetrazolo[5, l-a]purin-7-one 318, respectively (86H1899) (Scheme 92). 

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