Synthesis and anti-HIV-1 activity of a series of 1-(alkoxymethyl)-5-alkyl-6-(arylselenenyl)uracils and -2-thiouracils

A series of 1-(alkoxymethyl)-5-alkyl-6-(phenylselenenyl)uracils and -2-thiouracils modified at the 3- and/or 5-posiuon of the C-6 phenylselenenyl ring with methyl or fluoro substituent has been synthesized and tested for their ability to inhibit HIV-1 replication. Lithiation of the acyclic uracil and 2-thiouracil derivatives 11-14 and 27-32 with lithium diisopropylamide or lithium bis(trimethylsilyl)amide followed by reaction with an appropriate diaryl diselenide afforded 6-arylselenenyl compounds 18-26 after removal of the tert-butyl-dimethylsilyl protecting group and 35-47. Compounds 48-54 were prepared from compounds 38-44 by oxidative hydrolysis of the thione function. Of these compounds, 50 inhibited HIV-1 replication in human T₄ lymphoblastoid cells at a 50% effective concentration (EC₅₀) of 0.0047 μM with a selectivity index of >42600.