Purine Nucleoside Compounds

As an important biological molecue, adenosine is widely used in iatrology as a clinical medicine to protect heart or treat coronary heart disease. 8-Bromoadenosine is a useful intermediate on the synthesis of some analogs of adenosine, which can restrain the virus' vitality or tumour.Three methods are described to synthesize β-adenosine by using tetraacetyl -ribofuranose and adenine as two reactants. l)Fusion Method, tetraacetylriblfuranose and heterocycle base react in the precense of iodine by heating.Because of its shortage in stereoelective,the mixture of a- and P-adenosine is obtained after deacetylation and then needs to be separated through silicagel column. 2)Heavy metal method, P-adenosineis obtained by using chloromeruri N6-benzoyladenie and triacetylribo -furanosyl chloride as reagents in which chloromercuiri is used as catalyst. Because of its better stereoelective, silicagel column is not needed.3)Silylation method, Silylated N6-benzoyladenine without separation reacts with tetraacetylribofuranose, catalysted by SnCl4. It is not stereospecific and the product also needs to be separated through silicagel column regardless of the simple process and the moderate condition.Furthermore, the synthesis of 8-bromoadenosine of which the productivity is pretty high is also discussed by using adenosine and bromine reacting in the buffer solution ofNaOAc.