Synthesis of N-[4-[1-ethyl-2-(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)ethyl]benzoyl]-L-glutamic acid as an antifolate.

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Gangjee A, Zeng Y, McGuire JJ, Kisliuk RL

Synthesis of N-[4-[1-ethyl-2-(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)ethyl]benzoyl]-L-glutamic acid as an antifolate.

J Med Chem. 2002 Apr 25;45(9):1942-8.

PubMed ID
11960504 [ View in PubMed
]
Abstract

N-[4-[1-Ethyl-2-(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)ethyl]benzoyl]-L-glutamic acid 3 was designed and synthesized to investigate the effect of homologation of a C9-methyl to an ethyl on dihydrofolate reductase (DHFR) inhibition and on antitumor activity. Compound 3 was obtained via a concise seven step synthesis starting from palladium-catalyzed carbonylation of 4-propionylphenol, followed by a Wittig reaction with 2,4-diamino-5-(chloromethyl)furo[2,3-d]pyrimidine (6), catalytic hydrogenation, hydrolysis, and standard peptide coupling with diethyl L-glutamate. The biological results indicated that extending the C9-methyl group to an ethyl on the C8-C9 bridge region (analogue 3) doubled the inhibitory potency against recombinant human (rh) DHFR (IC(50) = 0.21 microM) as compared to the C9-methyl analogue 1 and was 4-fold more potent than the C9-H analogue 2. As compared to 1, compound 3 demonstrated increased growth inhibitory potency against several human tumor cell lines in culture with GI(50) values < 1.0 x 10(-8) M. Compound 3 was also a weak inhibitor of rh thymidylate synthase. Compounds 1 and 3 were efficient substrates of human folylpolyglutamate synthetase (FPGS). Further evaluation of the cytotoxicity of 3 in methotrexate-resistant CCRF-CEM cell sublines and metabolite protection studies implicated DHFR as the primary intracelluar target. Thus, alkylation of the C9 position in the C8-C9 bridge of the classical 5-substituted 2,4-diaminofuro[2,3-d]pyrimidine is highly conducive to DHFR and tumor inhibitory activity as well as FPGS substrate efficiency.

DrugBank Data that Cites this Article

Binding Properties
DrugTargetPropertyMeasurementpHTemperature (°C)
MethotrexateDihydrofolate reductaseIC 50 (nM)22N/AN/ADetails