Facile synthesis of fused purines from 8-aminotheophylline

Fused purines 3a-f were prepared by one-step from 8-aminotheophylline ( 1 ) and α,ω-dibromoalkanes in N, N-dimethylformamide in the presence of sodium hydride. Reaction of 3c-e with chloroacetyl chloride followed by treatment with dimethylamine gave 6a-c . A one-step reaction of 1 with ethyl bromopropionate gave 1,3-dimethyl-1,2,3,4,6,7,8,9-octahydropyrimido2,1-f]purine-2,4,8-trione ( 7b ). Facile syntheses of 7a, c, d from 1 were also carried out.