Phenylselenenyl- and phenylthio-substituted pyrimidines as inhibitors of dihydrouracil dehydrogenase and uridine phosphorylase
摘要:
Lithiation of 5-bromo-2,4-bis (benzyloxy) pyrimidine (3) with n-BuLi at -80 degrees C followed by the addition of diphenyl diselenide or diphenyl disulfide as an electrophile furnished the corresponding 5-(phenylhetera)-2,4-bis(benzyloxy) pyrimidine, which on exposure to trimethylsilyl iodide in CH2-Cl-2 at room temperature yielded the 5-(phenylhetera)uracils in 70-75% yield. Similarly, the 6-(phenylhetera) uracils were prepared from 6-bromo-2,4-bis (benzyloxy) pyrimidine (10). 1-[(2-Hydroxyethoxy)methyl] -5-(phenylselenenyl)uracil (PSAU, 18) and 1-(ethoxymethyl)-5- (phenylselenenyl)uracil (17) were synthesized by the electrophilic addition of benzeneselenenyl chloride to the acyclic uracils under basic conditions. These compounds were evaluated for their ability to inhibit dihydrouracil dehydrogenase (DHUDase, E.C. 1.3.1.2), orotate phosphoribosyltransferase (OPRTase, E.C. 2.4.2.10), uridine phosphorylase (UrdPase, E.C. 2.4.2.3), and thymidine phosphorylase (dThdPase, E.C. 2.4.2.4). 5-(Phenylselenenyl)uracil (PSU, 6) and 5-(phenylthio)uracil (PTU, 7) inhibited DHUDase with apparent K-i values of 4.8 and 5.4 mu M, respectively. The corresponding 6-analogues, compounds 13 and 14, demonstrated inhibitory activity against OPRTase. PTU as well as PSU and its riboside, 2'-deoxyriboside, and acyclonucleosides were inhibitors of UrdPase, with PSAU (18) being the most potent with an apparent K-i value of 3.8 mu M. None of the compounds evaluated had any effect on dThdPase. Interestingly, most of the compounds showed modest selective anti-human-immunodeficiency-virus activity in acutely infected primary human lymphocytes.
Synthesis of substituted uracils by the reactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles under focused microwave irradiation
Undermicrowaveirradiation, the nucleophilic substitutionreactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles was complete within several minutes with yields up to 99%. The method using microwaveirradiation is superior to those conducted under conventional heating processes.
作者:Sergio A. Rodriguez、Leandro D. Mena、Maria T. Baumgartner
DOI:10.1071/ch15496
日期:——
Herein, we report a synthetic route to obtain aryl sulfides using inexpensive and non-toxic reactants and water as solvent, that avoids the use of catalysts or heating. The photoinduced reaction between soluble substrates and a series of thiols in alkaline aqueous medium produces the corresponding sulfides in moderate to good yields.
efficient iodide-catalyzed/hydrogen peroxide mediated sulfenylation and selenylation of unprotected uracil and its derivatives with simple thiols and diselenides was established. This coupling tolerates a broad variety of functional groups to provide diverse 5-sulfur/selenium-substituted uracilderivatives in good to excellent yields (up to 93%).
A recyclable iron/graphite (Fe/Cg) catalyst for the efficientC-S cross-coupling of various iodoarenes with aromatic/ aliphatic thiols has been developed under ligand-free conditions (26 examples, up to 99% yield). The catalyst can be easily recovered and recycled up to seven cycles without loss of activity.