Synthesis and biological activities of tricyclic conformationally restricted tetrahydropyrido annulated furo[2,3-d]pyrimidines as inhibitors of dihydrofolate reductases

Aleem Gangjee, Elfatih Elzein, Sherry F. Queener, John J. McGuire

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The synthesis of seven 2,4-diamino-5,6,7,8-tetrahydro-7-substituted pyrido[4',3':4,5]furo[2,3-d]pyrimidines 1-6 are reported as nonclassical antifolate inhibitors of dihydrofolate reductase (DHFR) and compound 7 as a classical antifolate inhibitor of tumor cells in culture. The compounds were designed as conformationally restricted analogues of trimetrexate. The synthesis was accomplished from the cyclocondensation of 3-bromo-4-piperidone with 2,4-diamino-6-hydroxypyrimidine to afford regiospecifically 2,4-diamino- 5,6,7,8-tetrahydropyrido-[4',3':4,5]furo[2,3-d]pyrimidine-7-hydrobromide (16). This in turn was alkylated with the appropriate benzyl halide to afford the target compounds 1-6. The classical antifolate 7 utilized 4- (chloromethyl)benzoyl-L-glutamic acid diethyl ester (17) instead of the benzyl halide for alkylation, followed by saponification to afford 7. Compounds 1-6 showed moderate inhibitory potency against DHFR from Pneumocystis carinii, Toxoplasma gondii, Mycobacterium avium, and rat liver. The classical analogue 7 was 88-fold more potent against M. avium DHFR than against rat liver DHFR. The classical analogue was also inhibitory against the growth of tumor cells, CCRF-CEM, and FaDu, in culture.

Original languageEnglish (US)
Pages (from-to)1409-1416
Number of pages8
JournalJournal of Medicinal Chemistry
Issue number9
StatePublished - Apr 23 1998


ASJC Scopus subject areas

  • Molecular Medicine
  • Drug Discovery

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