Synthesis of 5-Alkyl-6-arylmethyl-2-(7-bromo-3,5-dioxaheptylthio)-pyrimidin-4(1H)-ones and 7-Oxopyrimidino-1,5,3-oxathiazepines as NewS-DABO Analogues with Anti-HIV Activity

Summary. New S- DABO s with a long alkylating S-alkyl substituent showing antiretroviral activity against HIV-1 in the micromolar range were prepared from 5,6-disubstituted 4-oxo-2-thiopyrimidines and 1,7-dibromo-3,5-dioxaheptane. The analogues with an ethyl group in position 5 also showed activity in the micromolar range against a Tyr/8/Cys mutant strain of HIV-1. The S- DABO analogues 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 surprisingly all showed activity against HIV-1 in the micromolar range, as well as against a Tyr/8/Cys mutant strain of HIV-1. Some analogues of S- DABO with a thien-2-ylmethyl residue in position 6 were synthesized and tested against HIV-1 wild type, but they showed less or comparable activities to those of the corresponding 6-benzyl analogues.