7-Substituted 7-deaza-2'-deoxyguanosines: Regioselective halogenation of pyrrolo[2,3-d]pyrimidine nucleosides

Article abstract of DOI:10.1002/hlca.19950780505

The synthesis of 7-chloro-, 7-bromo-, and 7-iodo-substituted 7-deaza-2'-deoxyguanosine derivatives 2b-d is described. The regioselective 7-halogenation with N-halogenosuccinimides was accomplished using 7-[2-deoxy-3,5-O-di(2-methylpropanoyl)-β-D-erythro-pentofuranosyl]-2- formylamino)-4-methoxy-7H-pyrrolo[2,3-d]pyrimidine (4) as the common precursor. A one-pot reaction (2N aq. NaOH) of the halogenated intermediates 5a-c furnished the desired compounds. Also the 7-hexynyl derivative 2e of 7-deaza-2'-deoxyguanosine is described.