An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yields of the N-alkyl pyrimidines and purines were found to be excellent. An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide (TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yield of the N-alkyl pyrimidines and purines were found to be excellent.