Synthesis of 5-alkyl-6-arylmethyl-2-(7-bromo-3,5-dioxaheptylthio)-pyrimidin-4(1H)-ones and 7-oxopyrimidino-1,5,3-oxathiazepines as new S-DABO analogues with anti-HIV activity

New S-DABOs with a long alkylating S-alkyl substituent showing antiretrovir al activity against HIV-1 in the micromolar range were prepared from 5,6-di substituted 4-oxo-2-thiopyrimidines and 1,7-dibromo-3,5-dioxaheptane. The a nalogues with an ethyl group in position 5 also showed activity in the micr omolar range against a Tyr/8/Cys mutant strain of HIV-1. The S-DABO analogu es showing activity against the HIV-1 RT mutant strain were transformed to the N-3 and N-1 ring closed 7-oxo-pyrimidino-1,3,5-oxathiazepines which sur prisingly all showed activity against HIV-1 in the micromolar range, as wel l as against a Tyr/8/Cys mutant strain of HIV-1. Some analogues of S-DABO w ith a thien-7-ylmethyl residue in position 6 were synthesized and tested ag ainst HIV-1 wild type, hut they showed less or comparable activities to tho se of the corresponding 6-benzyl analogues.