Study of Direct Regioselective -Alkylation of 6-Substituted Purines and Their Modification at Position through O, S, N, and C Substituents.

A new direct regioselective method allowing the introduction of -alkyl groups into appropriate 6-substituted purine derivatives is developed. This method is based on a reaction of -trimethylsilylated purines with a -alkyl halide using SnCl as a catalyst. In this work, we study the structure and optimal reaction conditions leading to the isomer and in some cases also to the isomer. The main goal is devoted to preparing 7-(-butyl)-6-chloropurine as a suitable compound for other purine transformations. The stability of the -butyl group at the position is tested for classic model reactions, leading to the preparation of new 6,7-disubstituted purine derivatives, which is also interesting from the point of view of possible biological activity.