5-Substituted-2,4-diamino-6-[2-(phosphonomethoxy)ethoxy]pyrimidines-acyclic nucleoside phosphonate analogues with antiviral activity.
2,4-Diamino-6-hydroxypyrimidines substituted in position 5 by an allyl, benzyl, cyanomethyl, ethoxycarbonylmethyl, phenyl, cyclopropyl, or methyl group were prepared either by C5-alkylation or by formation of the pyrimidine ring by cyclization. Their alkylation with 2-[(diisopropoxyphosphoryl)methoxy]ethyl tosylate afforded N1- and O6-regioisomers that were separated and converted to the free phosphonic acids by treatment with bromotrimethylsilane followed by hydrolysis. Reaction of 2,4-diamino-6-[[(diisopropoxyphosphoryl)methoxy]ethoxy]pyrimidine with elemental bromine, N-chloro-, or N-iodosuccinimide gave the corresponding phosphorus-protected 5-bromo-, 5-chloro-, and 5-iodo derivatives, respectively. Their deprotection afforded 2,4-diamino-5-bromo- and -5-chloro-6-[2-(phosphonomethoxy)ethoxy]pyrimidines. 2,4-Diamino-5-methyl-6-[2-(phosphonomethoxy)ethoxy]pyrimidine was synthesized also by cross-coupling of the 5-bromo compound with AlMe(3), followed by deprotection. The compounds showed poor, if any, inhibitory activity against DNA viruses such as herpes simplex virus type 1 and type 2, cytomegalovirus, varicella-zoster virus, and vaccinia virus. In contrast, several 5-substituted 2,4-diaminopyrimidine derivatives markedly inhibited retrovirus replication in cell culture. The 5-methyl derivative was exquisitely inhibitory to human immunodeficiency virus and Moloney murine sarcoma virus-induced cytopathicity in cell culture (EC(50) approximately 0.00018 mumol/mL) but also cytostatic to CEM cell cultures. In contrast, the 5-halogen-substituted derivatives showed pronounced antiretroviral activity (EC(50) = 0.0023-0.0110 mumol/mL), comparable to that of the reference drugs adefovir and tenofovir, but were devoid of measurable toxicity at 0.3 mumol/mL.
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10, Prague 6, Czech Republic. holy@uochb.cas.cz
Dana
D
Hocková
Antonín
A
Holý
Milena
M
Masojídková
Graciela
G
Andrei
Robert
R
Snoeck
Erik
E
De Clercq
Jan
J
Balzarini
D019380:Anti-HIV Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D004267:DNA Viruses / Q000187:drug effects*; D006801:Humans; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D012190:Retroviridae / Q000187:drug effects*; D013329:Structure-Activity Relationship
D019380:Anti-HIV Agents; D000970:Antineoplastic Agents; D000998:Antiviral Agents; D009705:Nucleosides; D063065:Organophosphonates; D011743:Pyrimidines