An efficient and eco-friendly synthesis of 6-chloro-8-substituted-9H-purines using cellulose sulfuric acid as a reusable catalyst under solvent-free conditions

A simple and efficient catalytic protocol for the 6-chloro-8-substituted-9H-purine derivatives via the one-pot condensation of 6-chloropyrimidine-4,5-diamine and different aldehydes using cellulose sulfuric acid is reported. The present method offers several advantages such as high to excellent yields, short reaction times, recovery and reusability of catalyst, mild reaction conditions and easy workup procedures.