Synthesis of acyclic nucleosides using a new coupling agent of lithium bromide and trifluoroacetic acid

Abstract

Recently acyclic nucleosides have been intensively studied because they show interesting biological activities along with decreasing side effects in comparison with those of ribonucleosides. As a catalyst, tin tetrachloride is usually well used. However tin tetrachloride is hygroscopic and leads to the mixture of colloids which cause to separate product difficult. Thus, we examined several new lewis acids for catalysts and found a good catalyst of a mixture lithium bromide and trifluoroacetic acid which is useful for the synthesis of 2-mercapto pyrimidine acyclic nucleosides and purine nucleosides.