Synthetic Studies Directed towards Agelasine Analogs – Synthesis, Tautomerism, and Alkylation of 2‐Substituted N‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines

N‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines, carrying various substituents in the 2 positions, were synthesized by the N‐methylation of known 6‐chloropurines, followed by a displacement of the chlorine. Great variations in the amino/imino tautomer ratio among the compounds studied were observed. The tautomers were identified by NMR methods. Treatment of N‐methoxy‐9‐methyl‐9H‐purin‐6‐amines carrying alkyl, alkoxy, or amino substituents in the 2 position with benzyl bromide resulted in a mixture of N‐7‐ and N6‐benzylated compounds with the former as the major products. N‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines with strongly electronegative substituents at C‐2 hardly reacted at all under the same set of reaction conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)