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

摘要

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 N-6-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. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)