The mechanism of formation of N²-benzylguanine in the reaction of 2-amino-6-chloropurine with a large excess (12-13 molar eq) of sodium benzyl oxide in benzyl alcohol at 130°C was studied, N², O⁶-Dibenzylguanine, a reaction intermediate, was isolated and a possible mechanism for its formation is discussed. Furthermore, using this sodium benzyl oxide system, benzylation at the amino group of nucleic acid bases was facilitated.