Synthesis of purine and pyrimidine derivatives using CsCl catalyst and by deamination

Abstract

Purine and pyrimidine derivatives containing a tetrahydrofuran moiety were successfully synthesized by a condensation of 2-acetoxytetrahydrofuran and trimethylsilyl derivatives of purine or pyrimidine in the presence of catalytic amounts of cecium chloride in excellent yields. 9-(Tetrahydro-2-furyl) adenine and 1-(tetrahydro-2-furyl)-5-fluorouracil which are known to show antitumor activity as one of important cancer therapeutic agents were prepared by this method in excellent yields more than 90\%. The yields of tetrahydro-2-furyl nuclosidesof purine and pyrimidine derivatives are much higher than those from the known methods. Though the role of cesium chloride is not yet clear, it may be assumed that oxygen of ether oxygen to promote the carbonium electrophilicity at the carbon adjacent to the ether oxygen. Ceicum chloride appears to be promising catalyst for the condensation reaction.