{2-[6-chloro-2-(4-hexyl-3-hydroxyphenylamino)-purin-9-yl]-ethoxymethyl}-phosphonic acid diethyl ester
(2-{2-[3-(tert-butyldiphenylsiloxy)-4-butyl-phenylamino]-6-chloro-purin-9-yl}-ethoxymethyl)-phosphonic acid diethyl ester
(2-{2-[3-(tert-butyldiphenylsiloxy)-4-hexylphenylamino]-6-chloro-purin-9-yl}-ethoxymethyl)-phosphonic acid diethyl ester
toluene-4-sulfonic acid 2-(diethoxy-phosphorylmethoxy)-ethylester
[[2-(6-amino-9H-purine-9-yl)ethoxy]methyl]phosphonic acid diethyl ester