Regioselective alkylation reaction of purines under microwave irradiation

Abstract

The alkylation of purines which is generally carried out after anion formation by treatment with a base and alkyl halide is complicated and in the best cases, mixtures of N-alkylated compounds are obtained. Purine derivatives can be acquired from alkylation at N-7 and N-9. In this work, the reaction conditions have been optimized to obtain the alkylation products of N-9 regioselectively. Different bases have been tried and tetrabutylammonium hydroxide has led to the best results. The reaction depends on the type of base and solvent used and improves considerably when the aid of microwave irradiation is used, which also considerably reduces the reaction time by reducing the formation of secondary products.