Syntheses of N, N, 3- and N, N, 9-Trialkyladenines by Alkylation of N, N-Dialkyladenines

Alkylations of N, N-dimethyl-(Ia) and N, N-diethyladenine (Ib) with methyl iodide, ethyl iodide, and benzyl bromide in N, N-dimethylacetamide in the presence of potassium carbonate gave the corresponding N, N, 9-trialkyladenines (II) in 54-74% yields, as well as minor amounts of N, N, 3-trialkyladenines (III). The alkylation of I without base gave the latter compounds (III) in 76-90% yields.