Synthesis, Characterization and Antimicrobial Activity of Novel Substituted Purine Derivatives

Abstract

In the present work, three new compounds were synthesized (49a, 49b, 51). Compounds were synthesized as the reaction sequences outlined in scheme1. Nitration of the theophylline was carried out as per the literature method. In this theophylline was reacted with the 65% HNO3 in presence of the acetic anhydride at the 0-5oC. Acetic anhydride was used as a dehydrating agent in the nitration reactions. Reaction was carried out at a controlled temperature because; the high temperature may cause polynitration and oxidative breakdown of aromatic ring. Product was characterized by the FTIR, 1H NMR and mass spectra. The N-alkylation of 8-nitro theophylline can be done by using 1-chloro3-iodopropane as alkylating agent and K2CO3 as base, at controlled temperature condition to prevent polymerization and get better yield. Then the reaction of 7(2-chloro ethyl) 8-nitro theophylline, substituted aryl amines and KI was carried out in microwave oven at 140W for 15 minutes to obtain 1,3-dimethyl-7-{2-[(4-aryl amino] ethyl}-8-nitro-3, 7-dihydro-1H-purine-2, 6-dione. Keywords: Purine, Theophylline, 8-nitrotheophylline, Anti-microbial activity.