SYNTHESIS OF POLYMETHYLENE CHAIN-BRIDGED 6-SUBSTITUTED 8-AZAPURINES AND RELATED-COMPOUNDS

The synthesis of a series of polymethylene chain-bridged 8-azapurines as potential DNA intercalating agents is described. N,N'-Bis(5-amino-6-chloro-4-pyrimidyl)-1,3-diaminopropane (III), N,N'-bis(5-amino-6-chloro-4-pyrimidyl)-1,8-diaminooctane (IV), and N,N'-bis(5-amino-6-chloro-4-pyrimidyl)-1,12-diaminododecane (V) were synthesized from 5-amino-4,6-dichloropyrimidine (I) and 1,3-diaminopropane (II, n = 3), 1,8-diaminooctane (II, n = 8), and 1,12-diaminododecane (II, n = 12), respectively, as the starting materials. 1,3-Bis(6-chloro-9-purinyl)propane (VI), 1,8-bis(6-chloro-9-purinyl)octane (VII), and 1,12-bis(6-chloro-9-purinyl)dodecane (VIII) were prepared by acid-catalyzed reaction of the corresponding pyrimidines III-V with triethyl orthoformate in N,N-dimethylacetamide. The polymethylene chain-bridged 6-hydroxy-8-azapurines XII-XIV were obtained via diazotization of the corresponding pyrimidines. The spectral data and other physical properties of the new compounds have been determined.